mcp2515: Initial implementation; C; C++

The mcp2515 is a CAN bus controller.  It was developed using the Seeed
CAN bus shield.

Signed-off-by: Jon Trulson <jtrulson@ics.com>

examples/c++/CMakeLists.txt

@@ -327,6 +327,7 @@ add_example (ecezo)
 add_example (mb704x)
 add_example (rf22-server)
 add_example (rf22-client)
+add_example (mcp2515)
 
 # These are special cases where you specify example binary, source file and module(s)
 include_directories (${PROJECT_SOURCE_DIR}/src)
@@ -369,3 +370,4 @@ if (OPENZWAVE_FOUND)
   add_custom_example (tzemt400-example-cxx tzemt400.cxx ozw)
 endif()
 add_custom_example (nmea_gps_i2c_example-cxx nmea_gps_i2c.cxx nmea_gps)
+add_custom_example (mcp2515-txrx-example-cxx mcp2515-txrx.cxx mcp2515)

examples/c++/mcp2515-txrx.cxx

@@ -0,0 +1,125 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <iostream>
+#include <signal.h>
+#include <upm_utilities.h>
+
+#include "mcp2515.hpp"
+
+using namespace std;
+
+bool shouldRun = true;
+
+void sig_handler(int signo)
+{
+  if (signo == SIGINT)
+    shouldRun = false;
+}
+
+
+int main(int argc, char **argv)
+{
+    signal(SIGINT, sig_handler);
+
+    // by default we just receive packets
+    bool do_tx = false;
+
+    // if an argument is given, we will transmit packets
+    if (argc > 1)
+        do_tx = true;
+//! [Interesting]
+
+    // NOTE: This example assumes that only two devices are connected
+    // to the CAN bus, and that both devices are running this example;
+    // one in TX (transmit) mode, and one in RX (receive) mode.
+
+    // If this is not the case, then in rx mode you may see other
+    // packets from other devices, or not, depending on whether the
+    // speed is correct for the network.  In tx mode, errors may be
+    // generated on the bus, especially if the CAN bus speed does not
+    // match the rest of the network.
+
+    // You should start the receiver example first.  The transmitter
+    // example will fail after about 5 seconds (timeout) of not being
+    // able to transmit a message.
+
+    // Instantiate a MCP2515 on SPI bus 0 using a hw CS pin (-1).
+    upm::MCP2515 *sensor = new upm::MCP2515(0, 9);
+
+    // By default, after initialization, the baud rate is set to
+    // 50Kbps, and the mode is NORMAL, so we don't need to set any of
+    // that here.
+
+    // our TX payload.  If transmitting, the first number will be
+    // incremented (and rollover) on each transmission.
+    string myPayload = "01234567";
+
+    while (shouldRun)
+    {
+        if (do_tx)
+        {
+            cout << "Loading a packet of 8 numbers (0-7) into a TX buffer..."
+                 << endl;
+            sensor->loadTXBuffer(MCP2515_TX_BUFFER0, 0, false, false,
+                                 myPayload);
+
+            // now lets try to transmit it
+            cout << "Transmitting packet..." << endl;
+            sensor->transmitBuffer(MCP2515_TX_BUFFER0, true);
+
+            myPayload[0]++;
+            cout << "Transmit successful" << endl;
+            cout << endl;
+
+            upm_delay_ms(500);
+        }
+        else
+        {
+            // RX mode
+            // Look for a packet waiting for us in RXB0
+            if (sensor->rxStatusMsgs() == MCP2515_RXMSG_RXB0)
+            {
+                cout << "Packet received in RXB0, decoding..." << endl;
+
+                // now lets retrieve and print it
+                sensor->getRXMsg(MCP2515_RX_BUFFER0);
+
+                sensor->printMsg();
+                cout << endl;
+            }
+
+            upm_delay_ms(100);
+        }
+    }
+
+    cout << "Exiting..." << endl;
+
+    delete sensor;
+//! [Interesting]
+
+    return 0;
+}

examples/c++/mcp2515.cxx

@@ -0,0 +1,79 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <iostream>
+
+#include "mcp2515.hpp"
+
+using namespace std;
+
+int main(int argc, char **argv)
+{
+//! [Interesting]
+
+    // Instantiate a MCP2515 on SPI bus 0 using a hw CS pin (-1).
+    upm::MCP2515 *sensor = new upm::MCP2515(0, -1);
+
+    cout << "Setting loopback mode..." << endl;
+
+    // set the mode to loopback mode.  In loopback mode, transmitted
+    // packets are sent directly to an appropriate receive buffer
+    // without actually going out onto the CAN bus.
+    sensor->setOpmode(MCP2515_OPMODE_LOOPBACK);
+
+    // lets build up a packet and try loading it (8 bytes max).
+    string myPayload = "01234567";
+    cout << "Loading a packet of 8 numbers (0-7) into a TX buffer..." << endl;
+    sensor->loadTXBuffer(MCP2515_TX_BUFFER0, 0, false, false, myPayload);
+
+    // now lets try to transmit it
+    cout << "Transmitting packet..." << endl;
+    sensor->transmitBuffer(MCP2515_TX_BUFFER0, true);
+
+    cout << "Transmit successful" << endl;
+
+    // There should now be a packet waiting for us in RXB0
+    if (sensor->rxStatusMsgs() == MCP2515_RXMSG_RXB0)
+    {
+        cout << "Packet received in RXB0, decoding..." << endl;
+
+        // now lets retrieve and print it
+        sensor->getRXMsg(MCP2515_RX_BUFFER0);
+
+        sensor->printMsg();
+    }
+    else
+    {
+        cout << "No packet found, how strange." << endl;
+    }
+
+    cout << "Exiting..." << endl;
+
+    delete sensor;
+//! [Interesting]
+
+    return 0;
+}

examples/c/CMakeLists.txt

@@ -141,6 +141,7 @@ add_example (ms5803)
 add_example (ims)
 add_example (ecezo)
 add_example (mb704x)
+add_example (mcp2515)
 
 # Custom examples
 add_custom_example (nmea_gps_i2c-example-c nmea_gps_i2c.c nmea_gps)
@@ -149,3 +150,4 @@ add_custom_example (lcm1602-parallel-example-c lcm1602-parallel.c lcm1602)
 add_custom_example (rpr220-intr-example-c rpr220-intr.c rpr220)
 add_custom_example (md-stepper-example-c md-stepper.c md)
 add_custom_example (button_intr-example-c button_intr.c button)
+add_custom_example (mcp2515-txrx-example-c mcp2515-txrx.c mcp2515)

examples/c/mcp2515-txrx.c

@@ -0,0 +1,144 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <signal.h>
+#include <upm_utilities.h>
+
+#include "mcp2515.h"
+
+bool shouldRun = true;
+
+void sig_handler(int signo)
+{
+  if (signo == SIGINT)
+    shouldRun = false;
+}
+
+int main(int argc, char **argv)
+{
+    signal(SIGINT, sig_handler);
+
+    // by default we just receive packets
+    bool do_tx = false;
+
+    // if an argument is given, we will transmit packets
+    if (argc > 1)
+        do_tx = true;
+//! [Interesting]
+
+    // NOTE: This example assumes that only two devices are connected
+    // to the CAN bus, and that both devices are running this example;
+    // one in TX (transmit) mode, and one in RX (receive) mode.
+
+    // If this is not the case, then in rx mode you may see other
+    // packets from other devices, or not, depending on whether the
+    // speed is correct for the network.  In tx mode, errors may be
+    // generated on the bus, especially if the CAN bus speed does not
+    // match the rest of the network.
+
+    // You should start the receiver example first.  The transmitter
+    // example will fail after about 5 seconds (timeout) of not being
+    // able to transmit a message.
+
+    // Instantiate a MCP2515 on SPI bus 0 using a hw CS pin (-1).
+    mcp2515_context sensor = mcp2515_init(0, -1);
+
+    if (!sensor)
+    {
+        printf("mcp2515_init() failed\n");
+        return 1;
+    }
+
+    // By default, after initialization, the baud rate is set to
+    // 50Kbps, and the mode is NORMAL, so we don't need to set any of
+    // that here.
+
+    if (!do_tx)
+        printf("RX mode, waiting for packets...\n");
+
+    // our TX payload.  If transmitting, the first number will be
+    // incremented (and rollover) on each transmission.
+    uint8_t myPayload[8] = {0, 1, 2, 3, 4, 5, 6, 7};
+
+    while (shouldRun)
+    {
+        if (do_tx)
+        {
+            // lets build up a packet and try loading it.
+            printf("Loading a packet of 8 numbers into a tx buffer...\n");
+            if (mcp2515_load_tx_buffer(sensor, MCP2515_TX_BUFFER0, 0,
+                                       false, false, myPayload, 8))
+            {
+                printf("mcp2515_load_tx_buffer() failed\n");
+                return 1;
+            }
+
+            // now lets try to transmit it
+            printf("Transmitting packet...\n");
+            upm_result_t rv = 0;
+            if ((rv = mcp2515_transmit_buffer(sensor, MCP2515_TX_BUFFER0,
+                                              true)))
+            {
+                printf("mcp2515_transmit_buffer() failed with code %d\n", rv);
+                return 1;
+            }
+
+            // increment the first number for each transmission
+            myPayload[0]++;
+            printf("Transmit successful\n\n");
+            upm_delay_ms(500);
+        }
+        else
+        {
+            // RX mode
+            // Look for a packet waiting for us in RXB0
+            if (mcp2515_rx_status_msgs(sensor) == MCP2515_RXMSG_RXB0)
+            {
+                printf("Packet received in RXB0, decoding...\n");
+
+                // now lets retrieve it
+                MCP2515_MSG_T msg;
+                if (mcp2515_get_rx_msg(sensor, MCP2515_RX_BUFFER0, &msg))
+                {
+                    printf("mcp2515_get_rx_msg() failed\n");
+                    return 1;
+                }
+                mcp2515_print_msg(sensor, &msg);
+                printf("\n");
+            }
+
+            upm_delay_ms(100);
+        }
+
+    }
+
+    printf("Exiting...\n");
+
+    mcp2515_close(sensor);
+//! [Interesting]
+
+    return 0;
+}

examples/c/mcp2515.c

@@ -0,0 +1,101 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+
+#include "mcp2515.h"
+
+int main(int argc, char **argv)
+{
+//! [Interesting]
+
+    // Instantiate a MCP2515 on SPI bus 0 using a hw CS pin (-1).
+    mcp2515_context sensor = mcp2515_init(0, -1);
+
+    if (!sensor)
+    {
+        printf("mcp2515_init() failed\n");
+        return 1;
+    }
+
+    printf("Setting loopback mode...\n");
+
+    // set the mode to loopback mode.  In loopback mode, transmitted
+    // packets are sent directly to an appropriate receive buffer
+    // without actually going out onto the CAN bus.
+    if (mcp2515_set_opmode(sensor, MCP2515_OPMODE_LOOPBACK))
+    {
+        printf("mcp2515_set_opmode(loopback) failed.\n");
+        return 1;
+    }
+
+    // lets build up a packet and try loading it.
+    uint8_t myPayload[8] = {0, 1, 2, 3, 4, 5, 6, 7};
+    printf("Loading a packet of 8 numbers (0-7) into a TX buffer...\n");
+    if (mcp2515_load_tx_buffer(sensor, MCP2515_TX_BUFFER0, 0, false, false,
+                               myPayload, 8))
+    {
+        printf("mcp2515_load_tx_buffer() failed\n");
+        return 1;
+    }
+
+    // now lets try to transmit it
+    printf("Transmitting packet...\n");
+    upm_result_t rv = 0;
+    if ((rv = mcp2515_transmit_buffer(sensor, MCP2515_TX_BUFFER0, true)))
+    {
+        printf("mcp2515_transmit_buffer() failed with code %d\n", rv);
+        return 1;
+    }
+
+    printf("Transmit successful\n");
+
+    // There should now be a packet waiting for us in RXB0
+    if (mcp2515_rx_status_msgs(sensor) == MCP2515_RXMSG_RXB0)
+    {
+        printf("Packet received in RXB0, decoding...\n");
+
+        // now lets retrieve it
+        MCP2515_MSG_T msg;
+        if (mcp2515_get_rx_msg(sensor, MCP2515_RX_BUFFER0, &msg))
+        {
+            printf("mcp2515_get_rx_msg() failed\n");
+            return 1;
+        }
+
+        mcp2515_print_msg(sensor, &msg);
+    }
+    else
+    {
+        printf("No packet found, how strange.\n");
+    }
+
+    printf("Exiting...\n");
+
+    mcp2515_close(sensor);
+//! [Interesting]
+
+    return 0;
+}

examples/java/CMakeLists.txt

@@ -160,6 +160,7 @@ add_example(MS5803_Example ms5803)
 add_example(ECEZO_Example ecezo)
 add_example(IMS_Example ims)
 add_example(MB704X_Example mb704x)
+add_example(MCP2515_Example mcp2515)
 
 add_example_with_path(Jhd1313m1_lcdSample lcd i2clcd)
 add_example_with_path(Jhd1313m1Sample lcd i2clcd)
@@ -181,3 +182,4 @@ if (OPENZWAVE_FOUND)
   add_example_with_path(TZEMT400_Example ozw ozw)
 endif()
 add_example_with_path(NMEAGPS_I2C_Example nmea_gps nmea_gps)
+add_example_with_path(MCP2515_TXRX_Example mcp2515 mcp2515)

examples/java/MCP2515_Example.java

@@ -0,0 +1,73 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+import upm_mcp2515.MCP2515;
+
+public class MCP2515_Example
+{
+    public static void main(String[] args) throws InterruptedException
+    {
+// ! [Interesting]
+
+        // Instantiate a MCP2515 on SPI bus 0 using a hw CS pin (-1).
+        MCP2515 sensor = new MCP2515(0, -1);
+
+        // set the mode to loopback mode.  In loopback mode, transmitted
+        // packets are sent directly to an appropriate receive buffer
+        // without actually going out onto the CAN bus.
+        sensor.setOpmode(upm_mcp2515.MCP2515_OPMODE_T.MCP2515_OPMODE_LOOPBACK);
+
+        // lets build up a packet and try loading it (8 bytes max).
+        String myPayload = "01234567";
+        System.out.println("Loading a packet of 8 numbers (0-7) into a TX buffer...");
+        sensor.loadTXBuffer(upm_mcp2515.MCP2515_TX_BUFFER_T.MCP2515_TX_BUFFER0,
+                            0, false, false, myPayload);
+
+        // now lets try to transmit it
+        System.out.println("Transmitting packet...");
+        sensor.transmitBuffer(upm_mcp2515.MCP2515_TX_BUFFER_T.MCP2515_TX_BUFFER0,
+                              true);
+
+        System.out.println("Transmit successful");
+
+        // There should now be a packet waiting for us in RXB0
+        if (sensor.rxStatusMsgs() == upm_mcp2515.MCP2515_RXMSG_T.MCP2515_RXMSG_RXB0)
+        {
+            System.out.println("Packet received in RXB0, decoding...");
+
+            // now lets retrieve and print it
+            sensor.getRXMsg(upm_mcp2515.MCP2515_RX_BUFFER_T.MCP2515_RX_BUFFER0);
+
+            sensor.printMsg();
+        }
+        else
+        {
+            System.out.println("No packet found, how strange.");
+        }
+
+        System.out.println("Exiting...");
+
+// ! [Interesting]
+    }
+}

examples/java/MCP2515_TXRX_Example.java

@@ -0,0 +1,94 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+import upm_mcp2515.MCP2515;
+
+public class MCP2515_TXRX_Example
+{
+    public static void main(String[] args) throws InterruptedException
+    {
+// ! [Interesting]
+
+        // by default we just receive packets
+        Boolean do_tx = false;
+        if (args.length > 0)
+            do_tx = true;
+
+        // Instantiate a MCP2515 on SPI bus 0 using a hw CS pin (-1).
+        MCP2515 sensor = new MCP2515(0, -1);
+
+        // NOTE: This example assumes that only two devices are connected
+        // to the CAN bus, and that both devices are running this example;
+        // one in TX (transmit) mode, and one in RX (receive) mode.
+
+        // If this is not the case, then in rx mode you may see other
+        // packets from other devices, or not, depending on whether the
+        // speed is correct for the network.  In tx mode, errors may be
+        // generated on the bus, especially if the CAN bus speed does not
+        // match the rest of the network.
+
+        // You should start the receiver example first.  The transmitter
+        // example will fail after about 5 seconds (timeout) of not being
+        // able to transmit a message.
+
+        while (true)
+        {
+            if (do_tx)
+            {
+                // lets build up a packet and try loading it (8 bytes max).
+                String myPayload = "01234567";
+                System.out.println("Loading a packet of 8 numbers (0-7) into a TX buffer...");
+                sensor.loadTXBuffer(upm_mcp2515.MCP2515_TX_BUFFER_T.MCP2515_TX_BUFFER0,
+                                    0, false, false, myPayload);
+
+                // now lets try to transmit it
+                System.out.println("Transmitting packet...");
+                sensor.transmitBuffer(upm_mcp2515.MCP2515_TX_BUFFER_T.MCP2515_TX_BUFFER0,
+                                      true);
+
+                System.out.println("Transmit successful");
+                System.out.println();
+                Thread.sleep(500);
+            }
+            else
+            {
+                // There should now be a packet waiting for us in RXB0
+                if (sensor.rxStatusMsgs() == upm_mcp2515.MCP2515_RXMSG_T.MCP2515_RXMSG_RXB0)
+                {
+                    System.out.println("Packet received in RXB0, decoding...");
+
+                    // now lets retrieve and print it
+                    sensor.getRXMsg(upm_mcp2515.MCP2515_RX_BUFFER_T.MCP2515_RX_BUFFER0);
+
+                    sensor.printMsg();
+                    System.out.println();
+                }
+
+                Thread.sleep(100);
+            }
+        }
+
+// ! [Interesting]
+    }
+}

examples/javascript/mcp2515-txrx.js

@@ -0,0 +1,94 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+var sensorObj = require('jsupm_mcp2515');
+
+// Instantiate a MCP2515 on SPI bus 0 using a hw CS pin (-1).
+var sensor = new sensorObj.MCP2515(0, -1);
+
+// NOTE: This example assumes that only two devices are connected
+// to the CAN bus, and that both devices are running this example;
+// one in TX (transmit) mode, and one in RX (receive) mode.
+
+// If this is not the case, then in rx mode you may see other
+// packets from other devices, or not, depending on whether the
+// speed is correct for the network.  In tx mode, errors may be
+// generated on the bus, especially if the CAN bus speed does not
+// match the rest of the network.
+
+// You should start the receiver example first.  The transmitter
+// example will fail after about 5 seconds (timeout) of not being
+// able to transmit a message.
+
+function transmit(sensor)
+{
+    // lets build up a packet and try loading it (8 bytes max).
+    var myPayload = "01234567";
+    console.log("Loading a packet of 8 numbers (0-7) into a TX buffer...");
+    sensor.loadTXBuffer(sensorObj.MCP2515_TX_BUFFER0,
+                        0, false, false, myPayload);
+
+    // now lets try to transmit it
+    console.log("Transmitting packet...");
+    sensor.transmitBuffer(sensorObj.MCP2515_TX_BUFFER0, true);
+
+    console.log("Transmit successful");
+    console.log();
+}
+
+function receive(sensor)
+{
+    // There should now be a packet waiting for us in RXB0
+    if (sensor.rxStatusMsgs() == sensorObj.MCP2515_RXMSG_RXB0)
+    {
+        console.log("Packet received in RXB0, decoding...");
+
+        // now lets retrieve and print it
+        sensor.getRXMsg(sensorObj.MCP2515_RX_BUFFER0);
+
+        sensor.printMsg();
+        console.log();
+    }
+}
+
+// by default we just receive packets
+if (process.argv.length > 2)
+{
+    // transmit mode
+    interval = setInterval(function() { transmit(sensor); }, 500);
+}
+else
+{
+    // receive mode
+    interval = setInterval(function() { receive(sensor); }, 100);
+}
+
+process.on('SIGINT', function()
+{
+    sensor = null;
+    sensorObj.cleanUp();
+    sensorObj = null;
+    console.log("Exiting...");
+    process.exit(0);
+});

examples/javascript/mcp2515.js

@@ -0,0 +1,66 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+var sensorObj = require('jsupm_mcp2515');
+
+// Instantiate a MCP2515 on SPI bus 0 using a hw CS pin (-1).
+var sensor = new sensorObj.MCP2515(0, -1);
+
+// set the mode to loopback mode.  In loopback mode, transmitted
+// packets are sent directly to an appropriate receive buffer
+// without actually going out onto the CAN bus.
+sensor.setOpmode(sensorObj.MCP2515_OPMODE_LOOPBACK);
+
+// lets build up a packet and try loading it (8 bytes max).
+var myPayload = "01234567";
+console.log("Loading a packet of 8 numbers (0-7) into a TX buffer...");
+sensor.loadTXBuffer(sensorObj.MCP2515_TX_BUFFER0, 0, false, false, myPayload);
+
+// now lets try to transmit it
+console.log("Transmitting packet...");
+sensor.transmitBuffer(sensorObj.MCP2515_TX_BUFFER0, true);
+
+console.log("Transmit successful");
+
+// There should now be a packet waiting for us in RXB0
+if (sensor.rxStatusMsgs() == sensorObj.MCP2515_RXMSG_RXB0)
+{
+    console.log("Packet received in RXB0, decoding...");
+
+    // now lets retrieve and print it
+    sensor.getRXMsg(sensorObj.MCP2515_RX_BUFFER0);
+
+    sensor.printMsg();
+}
+else
+{
+    console.log("No packet found, how strange.");
+}
+
+console.log("Exiting...");
+
+sensor = null;
+sensorObj.cleanUp();
+sensorObj = null;
+process.exit(0);

examples/python/mcp2515-txrx.py

@@ -0,0 +1,99 @@
+#!/usr/bin/python
+# Author: Jon Trulson <jtrulson@ics.com>
+# Copyright (c) 2016 Intel Corporation.
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+from __future__ import print_function
+import time, sys, signal, atexit
+from upm import pyupm_mcp2515 as MCP2515
+
+def main():
+    # Instantiate a MCP2515 on SPI bus 0 using a hw CS pin (-1).
+    sensor = MCP2515.MCP2515(0, -1)
+
+    ## Exit handlers ##
+    # This function stops python from printing a stacktrace when you
+    # hit control-C
+    def SIGINTHandler(signum, frame):
+        raise SystemExit
+
+    # This function lets you run code on exit, including functions from sensor
+    def exitHandler():
+        print("Exiting")
+        sys.exit(0)
+
+    # Register exit handlers
+    atexit.register(exitHandler)
+    signal.signal(signal.SIGINT, SIGINTHandler)
+
+    # by default we just receive packets
+    do_tx = False;
+    if (len(sys.argv) > 1):
+        do_tx = True
+
+    # NOTE: This example assumes that only two devices are connected
+    # to the CAN bus, and that both devices are running this example;
+    # one in TX (transmit) mode, and one in RX (receive) mode.
+
+    # If this is not the case, then in rx mode you may see other
+    # packets from other devices, or not, depending on whether the
+    # speed is correct for the network.  In tx mode, errors may be
+    # generated on the bus, especially if the CAN bus speed does not
+    # match the rest of the network.
+
+    # You should start the receiver example first.  The transmitter
+    # example will fail after about 5 seconds (timeout) of not being
+    # able to transmit a message.
+
+    # By default, after initialization, the baud rate is set to
+    # 50Kbps, and the mode is NORMAL, so we don't need to set any of
+    # that here.
+
+    while (True):
+        if (do_tx):
+            print("Loading a packet of 8 numbers (0-7) into a TX buffer...")
+            myPayload = "01234567";
+            sensor.loadTXBuffer(MCP2515.MCP2515_TX_BUFFER0, 0, False,
+                                False, myPayload);
+
+            # now lets try to transmit it
+            print("Transmitting packet...")
+            sensor.transmitBuffer(MCP2515.MCP2515_TX_BUFFER0, True)
+
+            print("Transmit successful")
+            print()
+            time.sleep(.5)
+        else:
+            # RX mode
+            # Look for a packet waiting for us in RXB0
+            if (sensor.rxStatusMsgs() == MCP2515.MCP2515_RXMSG_RXB0):
+                print("Packet received in RXB0, decoding...")
+
+                # now lets retrieve and print it
+                sensor.getRXMsg(MCP2515.MCP2515_RX_BUFFER0)
+
+                sensor.printMsg();
+                print()
+
+    print("Exiting...")
+
+if __name__ == '__main__':
+    main()

examples/python/mcp2515.py

@@ -0,0 +1,79 @@
+#!/usr/bin/python
+# Author: Jon Trulson <jtrulson@ics.com>
+# Copyright (c) 2016 Intel Corporation.
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+from __future__ import print_function
+import time, sys, signal, atexit
+from upm import pyupm_mcp2515 as MCP2515
+
+def main():
+    # Instantiate a MCP2515 on SPI bus 0 using a hw CS pin (-1).
+    sensor = MCP2515.MCP2515(0, -1)
+
+    ## Exit handlers ##
+    # This function stops python from printing a stacktrace when you
+    # hit control-C
+    def SIGINTHandler(signum, frame):
+        raise SystemExit
+
+    # This function lets you run code on exit, including functions from sensor
+    def exitHandler():
+        print("Exiting")
+        sys.exit(0)
+
+    # Register exit handlers
+    atexit.register(exitHandler)
+    signal.signal(signal.SIGINT, SIGINTHandler)
+
+    print("Setting loopback mode...")
+
+    # set the mode to loopback mode.  In loopback mode, transmitted
+    # packets are sent directly to an appropriate receive buffer
+    # without actually going out onto the CAN bus.
+    sensor.setOpmode(MCP2515.MCP2515_OPMODE_LOOPBACK);
+
+    # lets build up a packet and try loading it (8 bytes max).
+    myPayload = "01234567";
+    print("Loading a packet of 8 numbers (0-7) into a TX buffer...")
+    sensor.loadTXBuffer(MCP2515.MCP2515_TX_BUFFER0, 0, False, False, myPayload);
+
+    # now lets try to transmit it
+    print("Transmitting packet...")
+    sensor.transmitBuffer(MCP2515.MCP2515_TX_BUFFER0, True);
+
+    print("Transmit successful")
+
+    # There should now be a packet waiting for us in RXB0
+    if (sensor.rxStatusMsgs() == MCP2515.MCP2515_RXMSG_RXB0):
+        print("Packet received in RXB0, decoding...")
+
+        # now lets retrieve and print it
+        sensor.getRXMsg(MCP2515.MCP2515_RX_BUFFER0);
+
+        sensor.printMsg();
+    else:
+        print("No packet found, how strange.")
+
+    print("Exiting...")
+
+if __name__ == '__main__':
+    main()

src/mcp2515/CMakeLists.txt

@@ -0,0 +1,8 @@
+upm_mixed_module_init (NAME mcp2515
+    DESCRIPTION "CAN bus controller"
+    C_HDR mcp2515.h mcp2515_regs.h
+    C_SRC mcp2515.c
+    CPP_HDR mcp2515.hpp
+    CPP_SRC mcp2515.cxx
+    CPP_WRAPS_C
+    REQUIRES mraa)

src/mcp2515/javaupm_mcp2515.i

@@ -0,0 +1,25 @@
+%module javaupm_mcp2515
+%include "../upm.i"
+%include "typemaps.i"
+%include "arrays_java.i"
+%include "../java_buffer.i"
+%include "std_string.i"
+%include "../carrays_uint8_t.i"
+
+%include "mcp2515_regs.h"
+%include "mcp2515.hpp"
+%{
+    #include "mcp2515.hpp"
+%}
+
+
+%pragma(java) jniclasscode=%{
+    static {
+        try {
+            System.loadLibrary("javaupm_mcp2515");
+        } catch (UnsatisfiedLinkError e) {
+            System.err.println("Native code library failed to load. \n" + e);
+            System.exit(1);
+        }
+    }
+%}

src/mcp2515/jsupm_mcp2515.i

@@ -0,0 +1,13 @@
+%module jsupm_mcp2515
+%include "../upm.i"
+%include "cpointer.i"
+%include "std_string.i"
+%include "../carrays_uint8_t.i"
+
+%pointer_functions(float, floatp);
+
+%include "mcp2515_regs.h"
+%include "mcp2515.hpp"
+%{
+    #include "mcp2515.hpp"
+%}

src/mcp2515/license.txt

@@ -0,0 +1,51 @@
+The table of CNF1-3 valuses used to set the CAN bus baudrate were
+taken from the Seeed studio code at:
+
+https://github.com/Seeed-Studio/CAN_BUS_Shield/
+
+/*
+  mcp_can.cpp
+  2012 Copyright (c) Seeed Technology Inc.  All right reserved.
+
+  Author:Loovee
+  2014-1-16
+
+  Contributor:
+
+  Cory J. Fowler
+  Latonita
+  Woodward1
+  Mehtajaghvi
+  BykeBlast
+  TheRo0T
+  Tsipizic
+  ralfEdmund
+  Nathancheek
+  BlueAndi
+  Adlerweb
+  Btetz
+  Hurvajs
+  xboxpro1
+
+  The MIT License (MIT)
+
+  Copyright (c) 2013 Seeed Technology Inc.
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy
+  of this software and associated documentation files (the "Software"), to deal
+  in the Software without restriction, including without limitation the rights
+  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+  copies of the Software, and to permit persons to whom the Software is
+  furnished to do so, subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in
+  all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+  THE SOFTWARE.
+*/

src/mcp2515/mcp2515.cxx

@@ -0,0 +1,253 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <unistd.h>
+#include <iostream>
+#include <stdexcept>
+#include <string>
+
+#include "mcp2515.hpp"
+
+using namespace upm;
+using namespace std;
+
+MCP2515::MCP2515(int bus, int csPin) :
+    m_mcp2515(mcp2515_init(bus, csPin))
+{
+    if (!m_mcp2515)
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_init() failed");
+}
+
+MCP2515::~MCP2515()
+{
+    mcp2515_close(m_mcp2515);
+}
+
+void MCP2515::reset()
+{
+    if (mcp2515_reset(m_mcp2515))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_reset() failed");
+}
+
+void MCP2515::setOpmode(MCP2515_OPMODE_T opmode)
+{
+    if (mcp2515_set_opmode(m_mcp2515, opmode))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_set_opmode() failed");
+}
+
+void MCP2515::setSpeed(MCP2515_SPEED_T speed)
+{
+    if (mcp2515_set_speed(m_mcp2515, speed))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_set_speed() failed");
+}
+
+void MCP2515::loadTXBuffer(MCP2515_TX_BUFFER_T bufnum, int id, bool ext,
+                  bool rtr, std::string payload)
+{
+    if (mcp2515_load_tx_buffer(m_mcp2515, bufnum, id, ext, rtr,
+                               (uint8_t *)payload.data(), payload.size()))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_load_tx_buffer() failed");
+
+}
+
+void MCP2515::transmitBuffer(MCP2515_TX_BUFFER_T bufnum, bool wait)
+{
+    if (mcp2515_transmit_buffer(m_mcp2515, bufnum, wait))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_transmit_buffer() failed");
+}
+
+bool MCP2515::isTXBufferFree(MCP2515_TX_BUFFER_T bufnum)
+{
+    return mcp2515_tx_buffer_is_free(m_mcp2515, bufnum);
+}
+
+MCP2515_TX_BUFFER_T MCP2515::findFreeTXBuffer()
+{
+    return mcp2515_find_free_tx_buffer(m_mcp2515);
+}
+
+void MCP2515::setTXBufferPriority(MCP2515_TX_BUFFER_T bufnum,
+                                  MCP2515_TXP_T priority)
+{
+    if (mcp2515_set_tx_buffer_priority(m_mcp2515, bufnum, priority))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_set_tx_buffer_priority() failed");
+}
+
+void MCP2515::abortTX(MCP2515_TX_BUFFER_T bufnum)
+{
+    if (mcp2515_abort_tx(m_mcp2515, bufnum))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_abort_tx() failed");
+}
+
+void MCP2515::setRXBufferMode(MCP2515_RX_BUFFER_T bufnum, MCP2515_RXMODE_T rxm)
+{
+    if (mcp2515_set_rx_buffer_mode(m_mcp2515, bufnum, rxm))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_set_rx_buffer_mode() failed");
+}
+
+MCP2515_RXMSG_T MCP2515::rxStatusMsgs()
+{
+    return mcp2515_rx_status_msgs(m_mcp2515);
+}
+
+MCP2515_MSGTYPE_T MCP2515::rxStatusMsgType()
+{
+    return mcp2515_rx_status_msg_type(m_mcp2515);
+}
+
+MCP2515_FILTERMATCH_T MCP2515::rxStatusFiltermatch()
+{
+    return mcp2515_rx_status_filtermatch(m_mcp2515);
+}
+
+upm_result_t MCP2515::getRXMsg(MCP2515_RX_BUFFER_T bufnum)
+{
+    return mcp2515_get_rx_msg(m_mcp2515, bufnum, &m_message);
+}
+
+void MCP2515::printMsg()
+{
+    mcp2515_print_msg(m_mcp2515, &m_message);
+}
+
+void MCP2515::installISR(int pin, void (*isr)(void *), void *arg)
+{
+    if (mcp2515_install_isr(m_mcp2515, pin, isr, arg))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_install_isr() failed");
+}
+
+void MCP2515::uninstallISR()
+{
+    mcp2515_uninstall_isr(m_mcp2515);
+}
+
+void MCP2515::setIntrEnables(uint8_t enables)
+{
+    if (mcp2515_set_intr_enables(m_mcp2515, enables))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_set_intr_enables() failed");
+}
+
+uint8_t MCP2515::getIntrFlags()
+{
+    uint8_t flags = 0;
+    if (mcp2515_get_intr_flags(m_mcp2515, &flags))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_get_intr_flags() failed");
+    return flags;
+}
+
+void MCP2515::setIntrFlags(uint8_t flags)
+{
+    if (mcp2515_set_intr_flags(m_mcp2515, flags))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_set_intr_flags() failed");
+}
+
+void MCP2515::clearIntrFlags(uint8_t flags)
+{
+    if (mcp2515_clear_intr_flags(m_mcp2515, flags))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_clear_intr_flags() failed");
+}
+
+uint8_t MCP2515::getErrorFlags()
+{
+    uint8_t flags = 0;
+    if (mcp2515_get_error_flags(m_mcp2515, &flags))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_get_error_flags() failed");
+    return flags;
+}
+
+void MCP2515::clearErrorFlags(uint8_t flags)
+{
+    if (mcp2515_clear_error_flags(m_mcp2515, flags))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_clear_error_flags() failed");
+}
+
+void MCP2515::setFilter(MCP2515_RX_FILTER_T filter, bool ext, int id)
+{
+    if (mcp2515_set_filter(m_mcp2515, filter, ext, id))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_set_filter() failed");
+}
+
+void MCP2515::setMask(MCP2515_RX_MASK_T mask, bool ext, int id)
+{
+    if (mcp2515_set_mask(m_mcp2515, mask, ext, id))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_set_mask() failed");
+}
+
+string MCP2515::busRead(uint8_t cmd, std::string args, int datalen)
+{
+    uint8_t data[datalen];
+
+    if (mcp2515_bus_read(m_mcp2515, cmd, (uint8_t *)args.data(), args.size(),
+                         data, datalen))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_bus_read() failed");
+    return string((char *)data, datalen);
+}
+
+void MCP2515::busWrite(uint8_t cmd, std::string data)
+{
+    if (mcp2515_bus_write(m_mcp2515, cmd, (uint8_t *)data.data(), data.size()))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_bus_write() failed");
+}
+
+void MCP2515::writeReg(uint8_t reg, uint8_t value)
+{
+    if (mcp2515_write_reg(m_mcp2515, reg, value))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_write_reg() failed");
+}
+
+void MCP2515::writeRegs(uint8_t reg, std::string buffer)
+{
+    if (mcp2515_write_regs(m_mcp2515, reg, (uint8_t *)buffer.data(),
+                           buffer.size()))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_write_regs() failed");
+}
+
+void MCP2515::bitModify(uint8_t addr, uint8_t mask, uint8_t value)
+{
+    if (mcp2515_bit_modify(m_mcp2515, addr, mask, value))
+        throw std::runtime_error(string(__FUNCTION__)
+                                 + ": mcp2515_bit_modify() failed");
+}

src/mcp2515/mcp2515.h

@@ -0,0 +1,525 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#pragma once
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <upm.h>
+
+#include <mraa/i2c.h>
+#include <mraa/spi.h>
+#include <mraa/gpio.h>
+
+#include <mcp2515_regs.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+    /**
+     * @file mcp2515
+     * @library mcp2515
+     * @brief C API for the MCP2515 CAN bus controller
+     *
+     * @include mcp2515.c
+     * @include mcp2515_regs.c
+     */
+
+    /**
+     * Device context
+     */
+    typedef struct _mcp2515_context {
+        mraa_spi_context        spi;
+
+        // CS pin, if we are using one
+        mraa_gpio_context       gpio;
+
+        // interrupt, if enabled
+        mraa_gpio_context       intr;
+    } *mcp2515_context;
+
+    /**
+     * MCP2515 initializer
+     *
+     * @param bus spi bus to use
+     * @param cs_pin The GPIO pin to use for Chip Select (CS).  Pass
+     * pass -1 if your CS is handled automatically by your SPI
+     * implementation (Edison).
+     * @return an initialized device context on success, NULL on error.
+     */
+    mcp2515_context mcp2515_init(int bus, int cs_pin);
+
+    /**
+     * MCP2515 close
+     *
+     * @param dev Device context.
+     */
+    void mcp2515_close(mcp2515_context dev);
+
+    /**
+     * Reset the device.
+     *
+     * @param dev Device context.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_reset(const mcp2515_context dev);
+
+    /**
+     * Set the operating mode of the device.  After initialization
+     * (mcp2515_init()), the device mode will be set to NORMAL.  Note
+     * that some operations require the device to be placed into CONFIG
+     * mode.  This function will wait until the selected mode has been
+     * entered.
+     *
+     * @param dev Device context.
+     * @param opmode One of the MCP2515_OPMODE_T values.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_set_opmode(const mcp2515_context dev,
+                                    MCP2515_OPMODE_T opmode);
+
+    /**
+     * Set the baud rate of the CAN bus.  All devices on a given CAN
+     * bus must be operating at the correct speed.  The device must be
+     * switched into CONFIG mode bofore this function will have any
+     * effect.  On initialization (mcp2515_init()), the default CAN
+     * bus speed will be set to 50Kbps.
+     *
+     * @param dev Device context.
+     * @param speed One of the MCP2515_SPEED_T values.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_set_speed(const mcp2515_context dev,
+                                   MCP2515_SPEED_T speed);
+
+    /**
+     * Load a transmit buffer with the id, payload, and other
+     * information.  This function does not actually transmit the
+     * buffer.  There are 3 TX buffers available.  The buffer must be
+     * free (ie: not awaiting transmit) before it can be loaded.  Once
+     * a TX buffer has been successfully loaded, it can be transmitted
+     * with the mcp2515_transmit_buffer() function.
+     *
+     * @param dev Device context.
+     * @param bufnum The buffer to load.  One of the
+     * MCP2515_TX_BUFFER_T values.
+     * @param id The integer representation of the CAN bus ID.
+     * @param ext True if the ID is an extended identifier, false otherwise.
+     * @param rtr True if this is a Remote Transfer Request, false otherwise.
+     * @param payload A pointer to an array of bytes that make up the
+     * payload to send.
+     * @param len The length of the payload.  The length is limited to
+     * 8.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_load_tx_buffer(const mcp2515_context dev,
+                                        MCP2515_TX_BUFFER_T bufnum,
+                                        int id, bool ext, bool rtr,
+                                        uint8_t *payload, int len);
+
+    /**
+     * Transmit a buffer already loaded by mcp2515_load_tx_buffer().
+     *
+     * @param dev Device context.
+     * @param bufnum The buffer to transmit.  One of the
+     * MCP2515_TX_BUFFER_T values.
+     * @param wait True if the function should wait until transmission
+     * is complete before returning, false otherwise.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_transmit_buffer(const mcp2515_context dev,
+                                         MCP2515_TX_BUFFER_T bufnum,
+                                         bool wait);
+
+    /**
+     * Determine whether a TX buffer is available for use or not. A TX
+     * buffer is unavailable if a transmit request is pending on it,
+     * but transmission has not yet completed.
+     *
+     * @param dev Device context.
+     * @param bufnum The buffer to check. One of the
+     * MCP2515_TX_BUFFER_T values.
+     * @return True if the buffer is availabe, false otherwise.
+     */
+    bool mcp2515_tx_buffer_is_free(const mcp2515_context dev,
+                                   MCP2515_TX_BUFFER_T bufnum);
+
+    /**
+     * Find a free TX buffer and return it.
+     *
+     * @param dev Device context.
+     * @return One of the MCP2515_TX_BUFFER_T values.  If no buffers
+     * are available, MCP2515_TX_NO_BUFFERS will be returned.
+     */
+    MCP2515_TX_BUFFER_T mcp2515_find_free_tx_buffer(const mcp2515_context dev);
+
+    /**
+     * Set the transmit priority of a TX buffer.  Higher priority
+     * buffers are always transmitted before lower priority buffers.
+     * This function can be called on a buffer at any time prior to
+     * actual transmission.
+     *
+     * @param dev Device context.
+     * @param bufnum The buffer to set priority for.  One of the
+     * MCP2515_TX_BUFFER_T values.
+     * @param priority The priority to set for the buffer.  One of the
+     * MCP2515_TXP_T values.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_set_tx_buffer_priority(const mcp2515_context dev,
+                                                MCP2515_TX_BUFFER_T bufnum,
+                                                MCP2515_TXP_T priority);
+
+    /**
+     * Abort a transmission that has been queued, but not yet
+     * completed.  This will also free up the TX buffer for future
+     * use.  Note, if you abort a transmission, but transmission has
+     * already started, this call will have no effect, and the buffer
+     * will complete transmission.
+     *
+     * @param dev Device context.
+     * @param bufnum The buffer to abort.  One of the
+     * MCP2515_TX_BUFFER_T values.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_abort_tx(const mcp2515_context dev,
+                                  MCP2515_TX_BUFFER_T bufnum);
+
+    /**
+     * Set the mode for an RX buffer.  The mode specifies, at a high
+     * level, what packets should be captured from the bus and placed
+     * into an RX buffer.  See the datasheet for details, but the
+     * default, MCP2515_RXMODE_ANY_FILTER, should be sufficient in
+     * most cases.  It is also possible to use this to restrict the
+     * types of CAN ids accepted (extended only, standard only) as
+     * well as a debug ANY_NOFILTER mode.
+     *
+     * @param dev Device context.
+     * @param bufnum The buffer to set the mode for.  One of the
+     * MCP2515_RX_BUFFER_T values.
+     * @param rxm The mode to set.  One of the MCP2515_RXMODE_T values.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_set_rx_buffer_mode(const mcp2515_context dev,
+                                            MCP2515_RX_BUFFER_T bufnum,
+                                            MCP2515_RXMODE_T rxm);
+
+    /**
+     * Return a bitmask indicating which of the 2 RX buffers have
+     * packets waiting in them.  This can be 0 (no packets), 1(RXB0),
+     * 2(RXB1), or 3 (RXB0 and RXB1).  This information is retrieved
+     * using the MCP2515_CMD_RX_STATUS command.
+     *
+     * @param dev Device context.
+     * @return A bitmask indicating which RX buffers (if any) have
+     * packets in them.  One of the MCP2515_RXMSG_T values.
+     */
+    MCP2515_RXMSG_T mcp2515_rx_status_msgs(const mcp2515_context dev);
+
+    /**
+     * Return the message type present in one of the RX buffers.  RXB0
+     * has the highest priority, so if both RX buffers are full, this
+     * function will only return data for the packet in RXB0.  This
+     * information is retrieved using the MCP2515_CMD_RX_STATUS
+     * command.
+     *
+     * @param dev Device context.
+     * @return One of the MCP2515_MSGTYPE_T values.
+     */
+    MCP2515_MSGTYPE_T mcp2515_rx_status_msg_type(const mcp2515_context dev);
+
+    /**
+     * Return the filter that matched an RX buffer.  RXB0 has the
+     * highest priority, so if both RX buffers are full, this function
+     * will only return data for the packet in RXB0.  This information
+     * is retrieved using the MCP2515_CMD_RX_STATUS command.
+     *
+     * @param dev Device context.
+     * @return One of the MCP2515_FILTERMATCH_T values.
+     */
+    MCP2515_FILTERMATCH_T mcp2515_rx_status_filtermatch(const mcp2515_context dev);
+
+    /**
+     * This function retrieves a message from the specified RX buffer.
+     * The message (MCP2515_MSG_T) contains all of the data in the
+     * packet, including id, rtr, ext, payload and payload length.  In
+     * addition, after retrieving the message, the RX buffer is freed
+     * to receive further data from the CAN bus.
+     *
+     * @param dev Device context.
+     * @param bufnum The buffer to retrieve.  One of the
+     * MCP2515_RX_BUFFER_T values.
+     * @param msg A pointer to a MCP2515_MSG_T, which will be filled
+     * with the decoded contents of the RX buffer.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_get_rx_msg(const mcp2515_context dev,
+                                    MCP2515_RX_BUFFER_T bufnum,
+                                    MCP2515_MSG_T *msg);
+
+    /**
+     * This is a utility function that accepts a MCP2515_MSG_T and
+     * prints out it's decoded contents.  This is of primary
+     * importance for debugging, and to simplify the examples
+     * somewhat.
+     *
+     * The output will look similar to:
+     *
+     * id 00000000 ext 0 rtr 0 filt 0 len 8
+     *          payload: 0xc8 0x01 0x02 0x03 0x04 0x05 0x06 0x07
+     *
+     * @param dev Device context.
+     * @param msg A pointer to a MCP2515_MSG_T containing the data to
+     * be printed out.
+     */
+    void mcp2515_print_msg(const mcp2515_context dev, MCP2515_MSG_T *msg);
+
+    /**
+     * Installs an interrupt service routine (ISR) to be called when
+     * an interrupt occurs.
+     *
+     * @param dev Device context.
+     * @param pin GPIO pin to use as the interrupt pin.
+     * @param fptr Pointer to a function to be called on interrupt.
+     * @param arg Pointer to an object to be supplied as an
+     * argument to the ISR.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_install_isr(const mcp2515_context dev, int pin,
+                                     void (*isr)(void *), void *arg);
+
+    /**
+     * Uninstalls the previously installed ISR
+     *
+     * @param dev Device context.
+     */
+    void mcp2515_uninstall_isr(const mcp2515_context dev);
+
+    /**
+     * Set the interrupt enables register.
+     *
+     * @param dev Device context.
+     * @param enables A bitmask of interrupts to enable from
+     * MCP2515_CANINT_BITS_T.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_set_intr_enables(const mcp2515_context dev,
+                                          uint8_t enables);
+
+    /**
+     * Retrieve the interrupt flags register.
+     *
+     * @param dev Device context.
+     * @param flags A pointer to a bitmask that will be filled with
+     * values from MCP2515_CANINT_BITS_T, indicating which interrupt
+     * flags are set.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_get_intr_flags(const mcp2515_context dev,
+                                        uint8_t *flags);
+
+    /**
+     * This function allows you to set specific interrupt flags.  If
+     * the corresponding interrupt enable is set, an interrupt will be
+     * generated.
+     *
+     * @param dev Device context.
+     * @param flags A bitmask of interrupt flags to set, from
+     * MCP2515_CANINT_BITS_T values.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_set_intr_flags(const mcp2515_context dev,
+                                        uint8_t flags);
+
+    /**
+     * This function allows you to clear specific interrupt flags.
+     * See the datasheet.  Some flags cannot be cleared until the
+     * underlying cause has been corrected.
+     *
+     * @param dev Device context.
+     * @param flags A bitmask of interrupt flags to clear, from
+     * MCP2515_CANINT_BITS_T values.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_clear_intr_flags(const mcp2515_context dev,
+                                          uint8_t flags);
+
+    /**
+     * Retrieve the error flags register
+     *
+     * @param dev Device context.
+     * @param flags A pointer to a uint8_t that will hold the flags
+     * with values from MCP2515_EFLG_BITS_T.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_get_error_flags(const mcp2515_context dev,
+                                         uint8_t *flags);
+
+    /**
+     * Clear error flags.  Note, some flags cannot be cleared
+     * until the underlying issues is resolved.
+     *
+     * @param dev Device context.
+     * @param flags A bitmask of values from MCP2515_EFLG_BITS_T
+     * specifying the flags to clear.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_clear_error_flags(const mcp2515_context dev,
+                                           uint8_t flags);
+
+    /**
+     * This function allows you to set one of the 6 RX filters
+     * available.  Filters 0 and 1 are for RXB0 only, while filters
+     * 2-5 are for RXB1.  See the datasheet for details on how these
+     * filters (along with the masks) are used to select candidate CAN
+     * bus data for retrieval from the CAN bus.
+     *
+     * These can only be set when the device is in CONFIG mode.
+     *
+     * @param dev Device context.
+     * @param filter One of the 6 MCP2515_RX_FILTER_T values.
+     * @param ext True if the id is extended, false for standard.
+     * @param id Integer representation of a CAN bus ID.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_set_filter(const mcp2515_context dev,
+                                    MCP2515_RX_FILTER_T filter, bool ext,
+                                    int id);
+
+    /**
+     * This function allows you to set one of the 2 RX masks.  Mask 0
+     * is for RXB0, mask 1 is for RXB1.  The masks specify which bits
+     * in the filters are used for matching CAN bus data.  See the
+     * datasheet for details on how these masks (along with the
+     * filters) are used to select candidate CAN bus data for retrieval
+     * from the CAN bus.
+     *
+     * These can only be set when the device is in CONFIG mode.
+     *
+     * @param dev Device context.
+     * @param mask One of the 2 MCP2515_RX_MASK_T values.
+     * @param ext True if the id is extended, false for standard.
+     * @param id Integer representation of a CAN bus ID.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_set_mask(const mcp2515_context dev,
+                                  MCP2515_RX_MASK_T mask, bool ext, int id);
+
+    /**
+     * Perform a bus read.  This function is exposed here for those
+     * users wishing to perform their own low level accesses.  This is
+     * a low level function, and should not be used unless you know
+     * what you are doing.
+     *
+     * @param dev Device context.
+     * @param cmd The command to send.
+     * @param args An array of arguments, or NULL.
+     * @param arglen The number of args, or 0.
+     * @param data A pointer to a buffer in which data will be read into.
+     * @param len The number of bytes to read.
+     * @return UPM result.
+     */
+    upm_result_t mcp2515_bus_read(const mcp2515_context dev, uint8_t cmd,
+                                  uint8_t *args, unsigned int arglen,
+                                  uint8_t *data, uint8_t len);
+
+    /**
+     * Perform a bus write.  This function is exposed here for those
+     * users wishing to perform their own low level accesses.  This is
+     * a low level function, and should not be used unless you know
+     * what you are doing.
+     *
+     * @param dev Device context
+     * @param cmd The command to send.
+     * @param data A pointer to a buffer containing data to write.
+     * @param len The number of bytes to write.
+     * @return UPM Status
+     */
+    upm_result_t mcp2515_bus_write(const mcp2515_context dev, uint8_t cmd,
+                                   uint8_t *data, uint8_t len);
+
+    /**
+     * Write to a specific register.  This function is exposed here
+     * for those users wishing to perform their own low level
+     * accesses.  This is a low level function, and should not be used
+     * unless you know what you are doing.
+     *
+     * @param dev Device context
+     * @param reg The register to write to.
+     * @param value The byte to write.
+     * @return UPM Status
+     */
+    upm_result_t mcp2515_write_reg(const mcp2515_context dev, uint8_t reg,
+                                   uint8_t value);
+
+    /**
+     * Write to multiple consecutive registers.  This function is
+     * exposed here for those users wishing to perform their own low
+     * level accesses.  This is a low level function, and should not
+     * be used unless you know what you are doing.
+     *
+     * @param dev Device context
+     * @param reg The register to start writing to.
+     * @param buffer A pointer to an array of bytes to write.
+     * @param len The number of bytes to write.
+     * @return UPM Status
+     */
+    upm_result_t mcp2515_write_regs(const mcp2515_context dev, uint8_t reg,
+                                    uint8_t *buffer, int len);
+
+    /**
+     * Read a register.  This function is exposed here for those users
+     * wishing to perform their own low level accesses.  This is a low
+     * level function, and should not be used unless you know what you
+     * are doing.
+     *
+     * @param dev Device context
+     * @param reg The register to read.
+     * @param buffer A pointer to a a byte where the value will be placed.
+     * @return UPM Status
+     */
+    upm_result_t mcp2515_read_reg(const mcp2515_context dev, uint8_t reg,
+                                  uint8_t *value);
+
+    /**
+     * Perform a bit modify operation on a register.  Only certain
+     * registers support this method of access - check the datasheet.
+     * This function is exposed here for those users wishing to
+     * perform their own low level accesses.  This is a low level
+     * function, and should not be used unless you know what you are
+     * doing.
+     *
+     * @param dev Device context
+     * @param addr The address of the register to access.
+     * @param mask A bitmask used to mask off value bits.
+     * @param value The value to write (bits masked by mask).
+     * @return UPM Status
+     */
+    upm_result_t mcp2515_bit_modify(const mcp2515_context dev, uint8_t addr,
+                                    uint8_t mask, uint8_t value);
+
+#ifdef __cplusplus
+}
+#endif

src/mcp2515/mcp2515.hpp

@@ -0,0 +1,522 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#pragma once
+
+#include <string>
+
+#include "mcp2515.h"
+
+namespace upm {
+
+    /**
+     * @brief MCP2515 Can bus controller
+     * @defgroup mcp2515 libupm-mcp2515
+     * @ingroup spi gpio
+     */
+
+    /**
+     * @library mcp2515
+     * @sensor mcp2515
+     * @comname MCP2515 CAN bus controller
+     * @man seeed
+     * @con spi gpio
+     * @web https://www.seeedstudio.com/CANBUS-Shield-p-2256.html
+     *
+     * @brief API for the MCP2515 CAN bus controller
+     *
+     * The MCP2515 is a stand-alone CAN controller developed to
+     * simplify applications that require interfacing with a CAN bus.
+     *
+     * This driver was developed using the Grove CAN bus shield
+     * version 1.2.
+     *
+     * An example using the loopback mode.
+     * @snippet mcp2515.cxx Interesting
+     * A simple transmit and receive example.
+     * @snippet mcp2515-txrx.cxx Interesting
+     */
+    class MCP2515 {
+    public:
+
+        /**
+         * MCP2515 constructor.
+         *
+         * @param bus spi bus to use
+         * @param cs_pin The GPIO pin to use for Chip Select (CS).  Pass
+         * pass -1 if your CS is handled automatically by your SPI
+         * implementation (Edison).
+         */
+        MCP2515(int bus, int csPin);
+
+        /**
+         * MCP2515 Destructor
+         */
+        ~MCP2515();
+
+        /**
+         * Reset the device.
+         *
+         */
+        void reset();
+
+        /**
+         * Set the operating mode of the device.  After initialization,
+         * the device mode will be set to NORMAL.  Note that some
+         * operations require the device to be placed into CONFIG mode.
+         * This function will wait until the selected mode has been
+         * entered.
+         *
+         * @param opmode One of the MCP2515_OPMODE_T values.
+         */
+        void setOpmode(MCP2515_OPMODE_T opmode);
+
+        /**
+         * Set the baud rate of the CAN bus.  All devices on a given
+         * CAN bus must be operating at the correct speed.  The device
+         * must be switched into CONFIG mode bofore this function will
+         * have any effect.  On initialization, the default CAN bus
+         * speed will be set to 50Kbps.
+         *
+         * @param speed One of the MCP2515_SPEED_T values.
+         */
+        void setSpeed(MCP2515_SPEED_T speed);
+
+        /**
+         * Load a transmit buffer with the id, payload, and other
+         * information.  This function does not actually transmit the
+         * buffer.  There are 3 TX buffers available.  The buffer must be
+         * free (ie: not awaiting transmit) before it can be loaded.  Once
+         * a TX buffer has been successfully loaded, it can be transmitted
+         * with the TransmitBuffer() method.
+         *
+         * @param bufnum The buffer to load.  One of the
+         * MCP2515_TX_BUFFER_T values.
+         * @param id The integer representation of the CAN bus ID.
+         * @param ext True if the ID is an extended identifier, false otherwise.
+         * @param rtr True if this is a Remote Transfer Request, false
+         * otherwise.
+         * @param payload A string containing the payload bytes.
+         * Maximum length is 8.
+         */
+        void loadTXBuffer(MCP2515_TX_BUFFER_T bufnum,
+                          int id, bool ext, bool rtr,
+                          std::string payload);
+
+        /**
+         * Transmit a buffer already loaded by loadTXBuffer().
+         *
+         * @param bufnum The buffer to transmit.  One of the
+         * MCP2515_TX_BUFFER_T values.
+         * @param wait True if the function should wait until transmission
+         * is complete before returning, false otherwise.
+         */
+        void transmitBuffer(MCP2515_TX_BUFFER_T bufnum, bool wait);
+
+        /**
+         * Determine whether a TX buffer is available for use or not. A TX
+         * buffer is unavailable if a transmit request is pending on it,
+         * but transmission has not yet completed.
+         *
+         * @param bufnum The buffer to check. One of the
+         * MCP2515_TX_BUFFER_T values.
+         * @return True if the buffer is availabe, false otherwise.
+         */
+        bool isTXBufferFree(MCP2515_TX_BUFFER_T bufnum);
+
+        /**
+         * Find a free TX buffer and return it.
+         *
+         * @return One of the MCP2515_TX_BUFFER_T values.  If no buffers
+         * are available, MCP2515_TX_NO_BUFFERS will be returned.
+         */
+        MCP2515_TX_BUFFER_T findFreeTXBuffer();
+
+        /**
+         * Set the transmit priority of a TX buffer.  Higher priority
+         * buffers are always transmitted before lower priority buffers.
+         * This function can be called on a buffer at any time prior to
+         * actual transmission.
+         *
+         * @param bufnum The buffer to set priority for.  One of the
+         * MCP2515_TX_BUFFER_T values.
+         * @param priority The priority to set for the buffer.  One of the
+         * MCP2515_TXP_T values.
+         */
+        void setTXBufferPriority(MCP2515_TX_BUFFER_T bufnum,
+                                 MCP2515_TXP_T priority);
+
+        /**
+         * Abort a transmission that has been queued, but not yet
+         * completed.  This will also free up the TX buffer for future
+         * use.  Note, if you abort a transmission, but transmission has
+         * already started, this call will have no effect, and the buffer
+         * will complete transmission.
+         *
+         * @param bufnum The buffer to abort.  One of the
+         * MCP2515_TX_BUFFER_T values.
+         */
+        void abortTX(MCP2515_TX_BUFFER_T bufnum);
+
+        /**
+         * Set the mode for an RX buffer.  The mode specifies, at a high
+         * level, what packets should be captured from the bus and placed
+         * into an RX buffer.  See the datasheet for details, but the
+         * default, MCP2515_RXMODE_ANY_FILTER, should be sufficient in
+         * most cases.  It is also possible to use this to restrict the
+         * types of CAN ids accepted (extended only, standard only) as
+         * well as a debug ANY_NOFILTER mode.
+         *
+         * @param bufnum The buffer to set the mode for.  One of the
+         * MCP2515_RX_BUFFER_T values.
+         * @param rxm The mode to set.  One of the MCP2515_RXMODE_T values.
+         */
+        void setRXBufferMode(MCP2515_RX_BUFFER_T bufnum,
+                             MCP2515_RXMODE_T rxm);
+
+        /**
+         * Return a bitmask indicating which of the 2 RX buffers have
+         * packets waiting in them.  This can be 0 (no packets), 1(RXB0),
+         * 2(RXB1), or 3 (RXB0 and RXB1).  This information is retrieved
+         * using the MCP2515_CMD_RX_STATUS command.
+         *
+         * @return A bitmask indicating which RX buffers (if any) have
+         * packets in them.  One of the MCP2515_RXMSG_T values.
+         */
+        MCP2515_RXMSG_T rxStatusMsgs();
+
+        /**
+         * Return the message type present in one of the RX buffers.  RXB0
+         * has the highest priority, so if both RX buffers are full, this
+         * function will only return data for the packet in RXB0.  This
+         * information is retrieved using the MCP2515_CMD_RX_STATUS
+         * command.
+         *
+         * @return One of the MCP2515_MSGTYPE_T values.
+         */
+        MCP2515_MSGTYPE_T rxStatusMsgType();
+
+        /**
+         * Return the filter that matched an RX buffer.  RXB0 has the
+         * highest priority, so if both RX buffers are full, this function
+         * will only return data for the packet in RXB0.  This information
+         * is retrieved using the MCP2515_CMD_RX_STATUS command.
+         *
+         * @return One of the MCP2515_FILTERMATCH_T values.
+         */
+        MCP2515_FILTERMATCH_T rxStatusFiltermatch();
+
+        /**
+         * This function retrieves a message from the specified RX
+         * buffer.  The message (MCP2515_MSG_T) contains all of the
+         * data in the packet, including id, rtr, ext, payload and
+         * payload length.  In addition, after retrieving the message,
+         * the RX buffer is freed to receive further data from the CAN
+         * bus.  The message is stored within the class.
+         *
+         * @param bufnum The buffer to retrieve.  One of the
+         * MCP2515_RX_BUFFER_T values.
+         */
+        upm_result_t getRXMsg(MCP2515_RX_BUFFER_T bufnum);
+
+        /**
+         * This is a utility function prints the current (last
+         * received) messages decoded contents.  This is of
+         * primary importance for debugging, and to simplify the
+         * examples somewhat.
+         *
+         * The output will look similar to:
+         *
+         * id 00000000 ext 0 rtr 0 filt 0 len 8
+         *          payload: 0xc8 0x01 0x02 0x03 0x04 0x05 0x06 0x07
+         *
+         */
+        void printMsg();
+
+
+        /**
+         * This method returns the id of a received message.  It will
+         * only be valid after a successful completion of rxGetMsg().
+         *
+         * @return ID of the last received message.
+         */
+        int msgGetID()
+        {
+            return m_message.id;
+        }
+
+        /**
+         * This method returns the RTR flag of a received message.  It will
+         * only be valid after a successful completion of rxGetMsg().
+         *
+         * @return True if the message has the RTR flag set, false otherwise.
+         */
+        bool msgGetRTR()
+        {
+            return m_message.rtr;
+        }
+
+        /**
+         * This method returns the EXT (extended ID) flag of a
+         * received message.  It will only be valid after a successful
+         * completion of rxGetMsg().
+         *
+         * @return True if the message has an extended ID, false otherwise.
+         */
+        bool msgGetEXT()
+        {
+            return m_message.ext;
+        }
+
+        /**
+         * This method returns the filter number that caused the
+         * message to be stored in the RX buffer.  It will only be
+         * valid after a successful completion of rxGetMsg().
+         *
+         * @return The filter number that was matched.
+         */
+        int msgGetFilterNum()
+        {
+            return m_message.filter_num;
+        }
+
+        /**
+         * This method returns the length of the payload of the RX
+         * buffer.  It will only be valid after a successful
+         * completion of rxGetMsg().
+         *
+         * @return Length of the payload in bytes, max 8.
+         */
+        int msgGetPayloadLen()
+        {
+            return m_message.len;
+        }
+
+        /**
+         * This method returns the contents of the payload in the last
+         * received message.  It will only be valid after a successful
+         * completion of rxGetMsg().
+         *
+         * @return String containing the payload.
+         */
+        std::string msgGetPayload()
+        {
+            return std::string((char *)m_message.pkt.data, m_message.len);
+        }
+
+#if defined(SWIGJAVA) || defined(JAVACALLBACK)
+        void installISR(int pin, jobject runnable)
+        {
+            installISR(pin, mraa_java_isr_callback, runnable);
+        }
+#else
+        /**
+         * Installs an interrupt service routine (ISR) to be called when
+         * an interrupt occurs.
+         *
+         * @param pin GPIO pin to use as the interrupt pin.
+         * @param fptr Pointer to a function to be called on interrupt.
+         * @param arg Pointer to an object to be supplied as an
+         * argument to the ISR.
+         */
+        void installISR(int pin, void (*isr)(void *), void *arg);
+#endif
+
+        /**
+         * Uninstalls the previously installed ISR
+         *
+         * @param dev Device context.
+         */
+        void uninstallISR();
+
+        /**
+         * Set the interrupt enables register.
+         *
+         * @param enables A bitmask of interrupts to enable from
+         * MCP2515_CANINT_BITS_T.
+         */
+        void setIntrEnables(uint8_t enables);
+
+        /**
+         * Retrieve the interrupt flags register.
+         *
+         * @return A bitmask that will be filled with values from
+         * MCP2515_CANINT_BITS_T, indicating which interrupt flags are
+         * set.
+         */
+        uint8_t getIntrFlags();
+
+        /**
+         * This function allows you to set specific interrupt flags.  If
+         * the corresponding interrupt enable is set, an interrupt will be
+         * generated.
+         *
+         * @param flags A bitmask of interrupt flags to set, from
+         * MCP2515_CANINT_BITS_T values.
+         */
+        void setIntrFlags(uint8_t flags);
+
+        /**
+         * This function allows you to clear specific interrupt flags.
+         * See the datasheet.  Some flags cannot be cleared until the
+         * underlying cause has been corrected.
+         *
+         * @param flags A bitmask of interrupt flags to clear, from
+         * MCP2515_CANINT_BITS_T values.
+         */
+        void clearIntrFlags(uint8_t flags);
+
+        /**
+         * Retrieve the error flags register
+         *
+         * @return A bitmask that will be filled with values from
+         * MCP2515_EFLG_BITS_T, indicating which error flags are set.
+         */
+        uint8_t getErrorFlags();
+
+        /**
+         * Clear error flags.  Note, some flags cannot be cleared
+         * until the underlying issues is resolved.
+         *
+         * @return A bitmask of values from MCP2515_EFLG_BITS_T,
+         * indicating which error flags to clear.
+         */
+        void clearErrorFlags(uint8_t flags);
+
+        /**
+         * This function allows you to set one of the 6 RX filters
+         * available.  Filters 0 and 1 are for RXB0 only, while filters
+         * 2-5 are for RXB1.  See the datasheet for details on how these
+         * filters (along with the masks) are used to select candidate CAN
+         * bus data for retrieval from the CAN bus.
+         *
+         * These can only be set when the device is in CONFIG mode.
+         *
+         * @param filter One of the 6 MCP2515_RX_FILTER_T values.
+         * @param ext True if the id is extended, false for standard.
+         * @param id Integer representation of a CAN bus ID.
+         */
+        void setFilter(MCP2515_RX_FILTER_T filter, bool ext, int id);
+
+        /**
+         * This function allows you to set one of the 2 RX masks.  Mask 0
+         * is for RXB0, mask 1 is for RXB1.  The masks specify which bits
+         * in the filters are used for matching CAN bus data.  See the
+         * datasheet for details on how these masks (along with the
+         * filters) are used to select candidate CAN bus data for retrieval
+         * from the CAN bus.
+         *
+         * These can only be set when the device is in CONFIG mode.
+         *
+         * @param mask One of the 2 MCP2515_RX_MASK_T values.
+         * @param ext True if the id is extended, false for standard.
+         * @param id Integer representation of a CAN bus ID.
+         */
+        void setMask(MCP2515_RX_MASK_T mask, bool ext, int id);
+
+
+    protected:
+        mcp2515_context m_mcp2515;
+
+        // We operate only on this message (for received messages) to
+        // simplify SWIG accesses.
+        MCP2515_MSG_T m_message;
+
+        /**
+         * Perform a bus read.  This function is exposed here for those
+         * users wishing to perform their own low level accesses.  This is
+         * a low level function, and should not be used unless you know
+         * what you are doing.
+         *
+         * @param cmd The command to send.
+         * @param args String containing arguments, or empty for no arguments.
+         * @param datalen The length of the data to read.
+         * @return A string containing the data.
+         */
+        std::string busRead(uint8_t cmd, std::string args, int datalen);
+
+        /**
+         * Perform a bus write.  This function is exposed here for those
+         * users wishing to perform their own low level accesses.  This is
+         * a low level function, and should not be used unless you know
+         * what you are doing.
+         *
+         * @param cmd The command to send.
+         * @param data A string containing the data to write.
+         * @param len The number of bytes to write.
+         */
+        void busWrite(uint8_t cmd, std::string data);
+
+        /**
+         * Write to a specific register.  This function is exposed here
+         * for those users wishing to perform their own low level
+         * accesses.  This is a low level function, and should not be used
+         * unless you know what you are doing.
+         *
+         * @param reg The register to write to.
+         * @param value The byte to write.
+         */
+        void writeReg(uint8_t reg, uint8_t value);
+
+        /**
+         * Write to multiple consecutive registers.  This function is
+         * exposed here for those users wishing to perform their own low
+         * level accesses.  This is a low level function, and should not
+         * be used unless you know what you are doing.
+         *
+         * @param reg The register to start writing to.
+         * @param buffer A string containing data to write.
+         */
+        void writeRegs(uint8_t reg, std::string buffer);
+
+        /**
+         * Read a register.  This function is exposed here for those users
+         * wishing to perform their own low level accesses.  This is a low
+         * level function, and should not be used unless you know what you
+         * are doing.
+         *
+         * @param reg The register to read.
+         * @return The register contents.
+         */
+        uint8_t readReg(uint8_t reg);
+
+        /**
+         * Perform a bit modify operation on a register.  Only certain
+         * registers support this method of access - check the datasheet.
+         * This function is exposed here for those users wishing to
+         * perform their own low level accesses.  This is a low level
+         * function, and should not be used unless you know what you are
+         * doing.
+         *
+         * @param addr The address of the register to access.
+         * @param mask A bitmask used to mask off value bits.
+         * @param value The value to write (bits masked by mask).
+         */
+        void bitModify(uint8_t addr, uint8_t mask, uint8_t value);
+
+    private:
+#if defined(SWIGJAVA) || defined(JAVACALLBACK)
+        void installISR(int pin, void (*isr)(void *), void *arg);
+#endif
+    };
+}

src/mcp2515/mcp2515_regs.h

@@ -0,0 +1,641 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// maximum number of bytes we can send/receive
+#define MCP2515_MAX_PAYLOAD_DATA (8)
+
+// This includes SIDH, SIDL, EID8, EID0, DLC, and 8 payload bytes.
+// This represents the non-control components of the RX and TX
+// buffers.
+#define MCP2515_MAX_PKT_DATA (13)
+// Now we break them out for clarity.  These are offsets into a
+// transmitted or received packet.
+#define MCP2515_PKT_SIDH     (0)
+#define MCP2515_PKT_SIDL     (1)
+#define MCP2515_PKT_EID8     (2)
+#define MCP2515_PKT_EID0     (3)
+#define MCP2515_PKT_DLC      (4)
+#define MCP2515_PKT_D0       (5)
+#define MCP2515_PKT_D1       (6)
+#define MCP2515_PKT_D2       (7)
+#define MCP2515_PKT_D3       (8)
+#define MCP2515_PKT_D4       (9)
+#define MCP2515_PKT_D5       (10)
+#define MCP2515_PKT_D6       (11)
+#define MCP2515_PKT_D7       (12)
+
+// The number of bytes that make up an ID (SIDH, SIDL, EID8, EID0)
+#define MCP2515_MAX_ID_BYTES (4)
+
+    // 4 byte SIDH, SIDL, SID8, SID0 id.  This is used only for
+    // converting back and forth from an integer and 4-byte device
+    // representation of a standard or extended ID.
+    typedef union {
+        uint8_t data[MCP2515_MAX_ID_BYTES];
+        struct {
+            uint8_t SIDH;
+            uint8_t SIDL;
+            uint8_t EID8;
+            uint8_t EID0;
+        };
+    } MCP2515_ID_T;
+
+    // 13 byte packet starting at SIDH.  This is used to represent
+    // packets for transmission and reception.
+    typedef union {
+        uint8_t data[MCP2515_MAX_PKT_DATA];
+        struct {
+            uint8_t SIDH; // Id data
+            uint8_t SIDL;
+            uint8_t EID8;
+            uint8_t EID0;
+            uint8_t DLC;  // DLC (data length)
+            uint8_t D0;   // start of 8 byte (max) payload
+            uint8_t D1;
+            uint8_t D2;
+            uint8_t D3;
+            uint8_t D4;
+            uint8_t D5;
+            uint8_t D6;
+            uint8_t D7;
+        };
+    } MCP2515_PKT_T;
+
+    // A received message.  This includes the packet, and some decoded
+    // data (rtr, ext, id, etc.
+    typedef struct {
+        int id;
+        bool rtr;
+        bool ext;
+        int filter_num;
+        int len;
+        MCP2515_PKT_T pkt;
+    } MCP2515_MSG_T;
+
+    // Registers
+    typedef enum {
+        // 5 RX filters, each composed of SIDH, SIDL, EID8, EID0.  We
+        // only specify the leading (SIDH) address here.
+
+        // first two filters are associated with rxb0
+        MCP2515_REG_FILTER0              = 0x00,
+        MCP2515_REG_FILTER1              = 0x04,
+        // remaining 4 filters are associated with rxb1
+        MCP2515_REG_FILTER2              = 0x08,
+        MCP2515_REG_FILTER3              = 0x10,
+        MCP2515_REG_FILTER4              = 0x14,
+        MCP2515_REG_FILTER5              = 0x18,
+
+        // 2 RX filter mask registers, like above, we only specify the
+        // SIDH address
+
+        // associated with rxb0
+        MCP2515_REG_MASK0                = 0x20,
+        // associated with rxb1
+        MCP2515_REG_MASK1                = 0x24,
+
+        MCP2515_REG_BFPCTL               = 0x0c,
+        MCP2515_REG_TXRTSCTRL            = 0x0d, // tx ready-to-send
+
+        // CANSTAT and CANCTRL are aliased in several locations to
+        // make it easier to get maximum data using burst reads.  In
+        // reality, they are the same register, but we list them all
+        // anyway for completeness.
+
+        // CANSTAT and aliases
+        MCP2515_REG_CANSTAT              = 0x0e,
+        MCP2515_REG_CANSTAT_0            = 0x0e, // same as CANSTAT
+
+        MCP2515_REG_CANSTAT_1            = 0x1e, // rest of the aliases
+        MCP2515_REG_CANSTAT_2            = 0x2e,
+        MCP2515_REG_CANSTAT_3            = 0x3e,
+        MCP2515_REG_CANSTAT_4            = 0x4e,
+        MCP2515_REG_CANSTAT_5            = 0x5e,
+        MCP2515_REG_CANSTAT_6            = 0x6e,
+        MCP2515_REG_CANSTAT_7            = 0x7e,
+
+        // CANCTRL and aliases
+        MCP2515_REG_CANCTRL              = 0x0f,
+        MCP2515_REG_CANCTRL_0            = 0x0f, // same as CANCTRL
+
+        MCP2515_REG_CANCTRL_1            = 0x1f, // rest of the aliases
+        MCP2515_REG_CANCTRL_2            = 0x2f,
+        MCP2515_REG_CANCTRL_3            = 0x3f,
+        MCP2515_REG_CANCTRL_4            = 0x4f,
+        MCP2515_REG_CANCTRL_5            = 0x5f,
+        MCP2515_REG_CANCTRL_6            = 0x6f,
+        MCP2515_REG_CANCTRL_7            = 0x7f,
+
+        MCP2515_REG_TEC                  = 0x1c, // tx error count
+        MCP2515_REG_REC                  = 0x1d, // rx error count
+
+        MCP2515_REG_CNF3                 = 0x28, // configuration bytes
+        MCP2515_REG_CNF2                 = 0x29,
+        MCP2515_REG_CNF1                 = 0x2a,
+
+        MCP2515_REG_CANINTE              = 0x2b, // intr enables
+        MCP2515_REG_CANINTF              = 0x2c, // intr flags
+
+        MCP2515_REG_EFLG                 = 0x2a, // error flags
+
+        // Start of the buffer reg ranges for tx and rx buffers.
+        // There are 3 transmit buffers and 2 rx buffers.  You can
+        // read and write 16 bytes (0x0f) starting at these locations
+        // to set and/get buffer control bits, message ids, msg
+        // content, and CANSTAT and CANCTRL regs in one bus transaction.
+
+        // See the datasheet page 61
+        MCP2515_REG_TXB0CTRL             = 0x30, // tx buffer 0 ctrl
+        MCP2515_REG_TXB1CTRL             = 0x40, // tx buffer 1 ctrl
+        MCP2515_REG_TXB2CTRL             = 0x50, // tx buffer 2 ctrl
+
+        MCP2515_REG_RXB0CTRL             = 0x60, // rx buffer 0 ctrl
+        MCP2515_REG_RXB1CTRL             = 0x70 // rx buffer 1 ctrl
+    } MCP2515_REG_T;
+
+    // MCP2515_REG_CANCTRL bits
+    typedef enum {
+        MCP2515_CANCTRL_CLKPRE0          = 0x01,
+        MCP2515_CANCTRL_CLKPRE1          = 0x02,
+        _MCP2515_CANCTRL_CLKPRE_MASK     = 3,
+        _MCP2515_CANCTRL_CLKPRE_SHIFT    = 0,
+
+        MCP2515_CANCTRL_CLKEN            = 0x04, //enable CLKOUT pin
+
+        MCP2515_CANCTRL_OSM              = 0x08, // one shot mode
+
+        MCP2515_CANCTRL_ABAT             = 0x10, // abort all pending tx
+
+        MCP2515_CANCTRL_REQOP0           = 0x20, // request new operating mode
+        MCP2515_CANCTRL_REQOP1           = 0x40,
+        MCP2515_CANCTRL_REQOP2           = 0x80,
+        _MCP2515_CANCTRL_REQOP_MASK      = 7,
+        _MCP2515_CANCTRL_REQOP_SHIFT     = 5,
+    } MCP2515_CANCTRL_BITS_T;
+
+    // MCP2515_CLKPRE values
+    typedef enum {
+        MCP2515_CLKPRE_DIV1              = 0, // sysclk/1
+        MCP2515_CLKPRE_DIV2              = 1, // sysclk/2
+        MCP2515_CLKPRE_DIV4              = 2, // sysclk/4
+        MCP2515_CLKPRE_DIV8              = 3  // sysclk/8
+    } MCP2515_CLKPRE_T;
+
+    // MCP2515_OPMODE values.  These are the same for the CANCTRL_REQOP and
+    // CANSTAT_OPMODE bitfields.
+    typedef enum {
+        MCP2515_OPMODE_NORMAL            = 0,
+        MCP2515_OPMODE_SLEEP             = 1,
+        MCP2515_OPMODE_LOOPBACK          = 2,
+        MCP2515_OPMODE_LISTENONLY        = 3,
+        MCP2515_OPMODE_CONFIG            = 4
+    } MCP2515_OPMODE_T;
+
+    // MCP2515_REG_CANSTAT bits
+    typedef enum {
+        // 0x01 reserved
+
+        MCP2515_CANSTAT_ICOD0            = 0x02, // intr flag code
+        MCP2515_CANSTAT_ICOD1            = 0x04,
+        MCP2515_CANSTAT_ICOD2            = 0x08,
+        _MCP2515_CANSTAT_ICOD_MASK       = 7,
+        _MCP2515_CANSTAT_ICOD_SHIFT      = 1,
+
+        // 0x10 reserved
+
+        MCP2515_CANSTAT_OPMODE0          = 0x20, // request new operating mode
+        MCP2515_CANSTAT_OPMODE1          = 0x40,
+        MCP2515_CANSTAT_OPMODE2          = 0x80,
+        _MCP2515_CANSTAT_OPMODE_MASK     = 7,
+        _MCP2515_CANSTAT_OPMODE_SHIFT    = 5,
+    } MCP2515_CANSTAT_BITS_T;
+
+    // MCP2515_REG_BFPCTL bits, Buffer Pin Control
+    typedef enum {
+        MCP2515_BFPCTL_B0BFM             = 0x01, // opmode bit
+        MCP2515_BFPCTL_B1BFM             = 0x02,
+
+        MCP2515_BFPCTL_B0BFE             = 0x04, // func enable bit
+        MCP2515_BFPCTL_B1BFE             = 0x08,
+
+        MCP2515_BFPCTL_B0BFS             = 0x10, // pin state (output mode only)
+        MCP2515_BFPCTL_B1BFS             = 0x20,
+
+        // 0x40-0x080 reserved
+    } MCP2515_BFPCTL_BITS_T;
+
+    // MCP2515_REG_TXRTSCTRL bits, TX RTS pin control
+    typedef enum {
+        MCP2515_TXRTSCTRL_B0RTSM          = 0x01, // pin mode
+        MCP2515_TXRTSCTRL_B1RTSM          = 0x02,
+        MCP2515_TXRTSCTRL_B2RTSM          = 0x04,
+
+        MCP2515_TXRTSCTRL_B0RTS           = 0x08, // pin state when in
+                                                  // input mode
+        MCP2515_TXRTSCTRL_B1RTS           = 0x10,
+        MCP2515_TXRTSCTRL_B2RTS           = 0x20,
+
+        // 0x40-0x80 reserved
+    } MCP2515_TXRTSCTRL_BITS_T;
+
+    // MCP2515_REG_EFLG bits, Error flags
+    typedef enum {
+        MCP2515_EFLG_EWARN               = 0x01, // error warning (TEC/REC > 96)
+        MCP2515_EFLG_RXWAR               = 0x02, // rx warning (REC > 96)
+        MCP2515_EFLG_TXWAR               = 0x04, // tx warning (REC > 96)
+
+        MCP2515_EFLG_RXEP                = 0x08, // rx error-passive
+        MCP2515_EFLG_TXEP                = 0x10, // tx error-passive
+
+        MCP2515_EFLG_TXBO                = 0x20, // tx bus off
+
+        MCP2515_EFLG_RX0OVR              = 0x40, // rx buf 0 overflow
+        MCP2515_EFLG_RX1OVR              = 0x80, // rx buf 1 overflow
+    } MCP2515_EFLG_BITS_T;
+
+    // MCP2515_REG_CANINTE and MCP2515_REG_CANINTF bits, interrupt
+    // enables and flags.  We use the same enum here as the two regs
+    // have the same bits.
+    typedef enum {
+        MCP2515_CANINT_RX0I              = 0x01, // rx buf 0 full
+        MCP2515_CANINT_RX1I              = 0x02, // rx buf 1 full
+
+        MCP2515_CANINT_TX0I              = 0x04, // tx buf 1 empty
+        MCP2515_CANINT_TX1I              = 0x08, // tx buf 2 empty
+        MCP2515_CANINT_TX2I              = 0x10, // tx buf 3 empty
+
+        MCP2515_CANINT_ERRI              = 0x20, // error intr
+        MCP2515_CANINT_WAKI              = 0x40, // wakeup intr
+
+        MCP2515_CANINT_MERR              = 0x80  // msg error
+    } MCP2515_CANINT_BITS_T;
+
+    // MCP2515_REG_TXBCTRL, TX control for tx buffers 0 (0x30), 1
+    // (0x40), and 2 (0x50)
+    typedef enum {
+        MCP2515_TXBCTRL_TXP0              = 0x01, // message priority
+        MCP2515_TXBCTRL_TXP1              = 0x02,
+        _MCP2515_TXBCTRL_TXP_MASK         = 3,
+        _MCP2515_TXBCTRL_TXP_SHIFT        = 0,
+
+        // 0x04 reserved
+
+        MCP2515_TXBCTRL_TXREQ             = 0x08, // tx request
+        MCP2515_TXBCTRL_TXERR             = 0x10, // tx error detected
+        MCP2515_TXBCTRL_MLOA              = 0x20, // msg lost arbitration
+        MCP2515_TXBCTRL_ABTF              = 0x40  // msg aborted flag
+
+        // 0x80 reserved
+    } MCP2515_TXBCTRL_BITS_T;
+
+    // MCP2515_TXBCTRL_TXP priority values
+    typedef enum {
+        MCP2515_TXP_LOWEST                = 0,
+        MCP2515_TXP_LOW                   = 1,
+        MCP2515_TXP_HIGH                  = 2,
+        MCP2515_TXP_HIGHEST               = 3
+    } MCP2515_TXP_T;
+
+    // MCP2515_TXBDLC bits, (addresses 0x35, 0x45, 0x55)
+    typedef enum {
+        MCP2515_TXBDLC_DLC0               = 0x01, // data length code
+        MCP2515_TXBDLC_DLC1               = 0x02, // max is 8 bytes
+        MCP2515_TXBDLC_DLC2               = 0x04,
+        MCP2515_TXBDLC_DLC3               = 0x08,
+        _MCP2515_TXBDLC_MASK              = 15,
+        _MCP2515_TXBDLC_SHIFT             = 0,
+
+        // 0x10-0x20 reserved
+
+        MCP2515_TXBDLC_RTR                = 0x40, // remote
+                                                  // transmission
+                                                  // request bit
+
+        // 0x80 reserved
+    } MCP2515_TXBDLC_BITS_T;
+
+    // MCP2515_REG_RXB0CTRL, RX control for rx buffer 0 (0x60)
+    typedef enum {
+        MCP2515_RXB0CTRL_FILHIT            = 0x01, // which filter was hit
+
+        MCP2515_RXB0CTRL_BUKT1             = 0x02, // readonly version of BUKT
+        MCP2515_RXB0CTRL_BUKT              = 0x04, // rollover enable (to rx1)
+
+        MCP2515_RXB0CTRL_RXRTR             = 0x08, // RTR request
+
+        // 0x10 reserved
+
+        MCP2515_RXB0CTRL_RXMODE0           = 0x20, // rx buf mode bits
+        MCP2515_RXB0CTRL_RXMODE1           = 0x40,
+        _MCP2515_RXB0CTRL_RXMODE_MASK      = 3,
+        _MCP2515_RXB0CTRL_RXMODE_SHIFT     = 5
+
+        // 0x80 reserved
+    } MCP2515_RXB0CTRL_BITS_T;
+
+    // These values determine whether the filters are used and what
+    // kinds of messages to accept.  They are the same for both rx
+    // buffers.
+    typedef enum {
+        MCP2515_RXMODE_ANY_FILTER          = 0, // std/ext based on filter
+        MCP2515_RXMODE_STANDARD_FILTER     = 1, // standard only, filter
+        MCP2515_RXMODE_EXTENDED_FILTER     = 2, // extended only, filter
+        MCP2515_RXMODE_ANY_NOFILTER        = 3  // any, no filter
+    } MCP2515_RXMODE_T;
+
+    // MCP2515_REG_RXB1CTRL, RX control for rx buffer 1 (0x70)
+    typedef enum {
+        MCP2515_RXB1CTRL_FILHIT0           = 0x01, // which filter was hit
+        MCP2515_RXB1CTRL_FILHIT1           = 0x02, // for a rollover, this can
+        MCP2515_RXB1CTRL_FILHIT2           = 0x04, // be filter 0 or 1 too.
+        _MCP2515_RXB1CTRL_FILHIT_MASK      = 7,
+        _MCP2515_RXB1CTRL_FILHIT_SHIFT     = 0,
+
+        MCP2515_RXB1CTRL_RXRTR             = 0x08, // RTR request
+
+        // 0x10 reserved
+
+        MCP2515_RXB1CTRL_RXMODE0           = 0x20, // rx buf mode bits
+        MCP2515_RXB1CTRL_RXMODE1           = 0x40,
+        _MCP2515_RXB1CTRL_RXMODE_MASK      = 3,
+        _MCP2515_RXB1CTRL_RXMODE_SHIFT     = 5
+
+        // 0x80 reserved
+    } MCP2515_RXB1CTRL_BITS_T;
+
+    // MCP2515_RXB1CTRL_FILHIT values for rx buffer 1
+    typedef enum {
+        MCP2515_FILHIT_F0                  = 0, // filter 0 hit (only if bukt)
+        MCP2515_FILHIT_F1                  = 1, // filter 1 hit (only if bukt)
+        MCP2515_FILHIT_F2                  = 2, // filter 2 hit
+        MCP2515_FILHIT_F3                  = 3,
+        MCP2515_FILHIT_F4                  = 4,
+        MCP2515_FILHIT_F5                  = 5
+    } MCP2515_FILHIT_T;
+
+    // Valid CANBUS speeds.  These are precomputed and represented in
+    // a table in mcp2515.c.  It is a requirement that the enum values
+    // below correspond to the indexes in the speed table.  Keep them
+    // in sync!  Add any new values to the end of this enum, and to
+    // the corresponding table in mcp2515.c.
+    //
+    // These values are valid only for 16Mhz clocks.
+    typedef enum {
+        MCP2515_SPEED_5KBPS                = 0,
+        MCP2515_SPEED_10KBPS               = 1,
+        MCP2515_SPEED_20KBPS               = 2,
+        MCP2515_SPEED_25KBPS               = 3,
+        MCP2515_SPEED_31_25KBPS            = 4, // 31.25kbps
+        MCP2515_SPEED_33KBPS               = 5,
+        MCP2515_SPEED_40KBPS               = 6,
+        MCP2515_SPEED_50KBPS               = 7,
+        MCP2515_SPEED_80KBPS               = 8,
+        MCP2515_SPEED_83KBPS               = 9,
+
+        MCP2515_SPEED_95KBPS               = 10,
+        MCP2515_SPEED_100KBPS              = 11,
+        MCP2515_SPEED_125KBPS              = 12,
+        MCP2515_SPEED_200KBPS              = 13,
+        MCP2515_SPEED_250KBPS              = 14,
+        MCP2515_SPEED_500KBPS              = 15,
+        MCP2515_SPEED_666KBPS              = 16,
+        MCP2515_SPEED_1000KBPS             = 17
+    } MCP2515_SPEED_T;
+
+    // MCP2515_RXBDLC bits, (addresses 0x65, 0x75)
+    typedef enum {
+        MCP2515_RXBDLC_DLC0               = 0x01, // data length code
+        MCP2515_RXBDLC_DLC1               = 0x02, // max is 8 bytes
+        MCP2515_RXBDLC_DLC2               = 0x04,
+        MCP2515_RXBDLC_DLC3               = 0x08,
+        _MCP2515_RXBDLC_MASK              = 15,
+        _MCP2515_RXBDLC_SHIFT             = 0,
+
+        // 0x10-0x20 reserved
+
+        MCP2515_RXBDLC_RTR                = 0x40, // remote
+                                                  // transmission
+                                                  // request bit, if
+                                                  // extended id
+
+        // 0x80 reserved
+    } MCP2515_RXBDLC_BITS_T;
+
+    // SPI commands - these are commands sent to the device to start
+    // certain operations.  The datasheet specifies that after CS is
+    // active, the first byte must be the command byte.  It is not
+    // possible to send multiple commands in a single transaction
+    // (a CS On/CS Off sequence).
+    typedef enum {
+        MCP2515_CMD_RESET                  = 0xc0,
+
+        MCP2515_CMD_READ                   = 0x03,
+
+        // These commands allows the specification of a read buffer.
+        // The real command is 0x90. The lower nibble is 0mn0,
+        // where m and n specify the 4 locations to start reading
+        // from.  In this list, we will enumerate all of them.
+        //
+        // n  m  cmd        real hex addr
+        // ------------------------------
+        // 0  0  RXB0SIDH   0x61
+        // 0  1  RXB0D0     0x66
+        // 1  0  RXB1SIDH   0x71
+        // 1  1  RXB1D0     0x76
+        MCP2515_CMD_READ_RXBUF_RXB0SIDH    = 0x90,
+        MCP2515_CMD_READ_RXBUF_RXB0D0      = 0x92,
+        MCP2515_CMD_READ_RXBUF_RXB1SIDH    = 0x94,
+        MCP2515_CMD_READ_RXBUF_RXB1D0      = 0x96,
+
+        MCP2515_CMD_WRITE                  = 0x02,
+
+        // This command allows speedier loading of tx buffer contents.
+        // The lower nibble is 0b0abc, where abc specifies 6 location
+        // addresses to start writing to.  This works similarly to the
+        // READ_RXBUF_* commands.
+        //
+        // a  b  c   cmd        real hex addr
+        // ----------------------------------
+        // 0  0  0   TXB0SIDH   0x31
+        // 0  0  1   TXB0D0     0x36
+        // 0  1  0   TXB1SIDH   0x41
+        // 0  1  1   TXB1D0     0x46
+        // 1  0  0   TXB2SIDH   0x51
+        // 1  0  1   TXB2D0     0x56
+        MCP2515_CMD_LOAD_TXBUF_TXB0SIDH    = 0x40,
+        MCP2515_CMD_LOAD_TXBUF_TXB0D0      = 0x41,
+        MCP2515_CMD_LOAD_TXBUF_TXB1SIDH    = 0x42,
+        MCP2515_CMD_LOAD_TXBUF_TXB1D0      = 0x43,
+        MCP2515_CMD_LOAD_TXBUF_TXB2SIDH    = 0x44,
+        MCP2515_CMD_LOAD_TXBUF_TXB2D0      = 0x45,
+
+        // Request to Send.  This is a quick way to request the
+        // sending of tx buffers without having to do a
+        // read/modify/write register sequence.  The lower 3 bits
+        // indicate which buffer(s) to setup for transmission.
+        //
+        // 0x8n Where n is 0b0xxx. bit 0 is for txb 0, bit 1 for txb 1
+        // and bit 2 for txb 2.
+        MCP2515_CMD_RTS                    = 0x80,
+        MCP2515_CMD_RTS_BUFFER0            = 0x81,
+        MCP2515_CMD_RTS_BUFFER1            = 0x82,
+        MCP2515_CMD_RTS_BUFFER2            = 0x84,
+
+        // return status bits for rx and tx. See MCP2515_RDSTATUS_BITS_T.
+        MCP2515_CMD_READ_STATUS            = 0xa0,
+
+        // returns information on which filters have been matched.
+        // See MCP2515_RXSTATUS_BITS_T.
+        MCP2515_CMD_RX_STATUS              = 0xb0,
+
+        // This command allows for certain registers to have certain
+        // bit(s) modified w/o going through a read/modify/write cycle
+        // of the whole register.  See the datasheet - only certain
+        // registers can be used with this command.
+        //
+        // The format for this command is: cmd, addr, mask, value
+        MCP2515_CMD_BIT_MODIFY             = 0x05
+    } MCP2515_CMD_T;
+
+    // This bitfield is the contents of the byte returned from a
+    // CMD_READ_STATUS command.
+    typedef enum {
+        MCP2515_RDSTATUS_RX0IF              = 0x01, // rx buf 0 full IF
+        MCP2515_RDSTATUS_RX1IF              = 0x02, // rx buf 1 full IF
+        MCP2515_RDSTATUS_TXB0REQ            = 0x04, // TX buf 0 req bit
+        MCP2515_RDSTATUS_TXB0IF             = 0x08, // TX buf 0 empty IF
+        MCP2515_RDSTATUS_TXB1REQ            = 0x10, // TX buf 1 req bit
+        MCP2515_RDSTATUS_TXB1IF             = 0x20, // TX buf 1 empty IF
+        MCP2515_RDSTATUS_TXB2REQ            = 0x40, // TX buf 2 req bit
+        MCP2515_RDSTATUS_TXB2IF             = 0x80  // TX buf 2 empty IF
+    } MCP2515_RDSTATUS_BITS_T;
+
+    // This bitfield is the contents of the byte returned from a
+    // CMD_READ_RX_STATUS command.
+    typedef enum {
+        MCP2515_RXSTATUS_FILTERMATCH0       = 0x01,
+        MCP2515_RXSTATUS_FILTERMATCH1       = 0x02,
+        MCP2515_RXSTATUS_FILTERMATCH2       = 0x04,
+        _MCP2515_RXSTATUS_FILTERMATCH_MASK  = 7,
+        _MCP2515_RXSTATUS_FILTERMATCH_SHIFT = 0,
+
+        MCP2515_RXSTATUS_MSGTYPE0           = 0x08,
+        MCP2515_RXSTATUS_MSGTYPE1           = 0x10,
+        _MCP2515_RXSTATUS_MSGTYPE_MASK      = 3,
+        _MCP2515_RXSTATUS_MSGTYPE_SHIFT     = 3,
+
+        // 0x20 is not mentioned in the DS
+
+        MCP2515_RXSTATUS_RXMSG0             = 0x40,
+        MCP2515_RXSTATUS_RXMSG1             = 0x80,
+        _MCP2515_RXSTATUS_RXMSG_MASK        = 3,
+        _MCP2515_RXSTATUS_RXMSG_SHIFT       = 6
+    } MCP2515_RXSTATUS_BITS_T;
+
+    // MCP2515_RXSTATUS_FILTERMATCH values
+    typedef enum {
+        MCP2515_FILTERMATCH_RXF0            = 0,
+        MCP2515_FILTERMATCH_RXF1            = 1,
+        MCP2515_FILTERMATCH_RXF2            = 2,
+        MCP2515_FILTERMATCH_RXF3            = 3,
+        MCP2515_FILTERMATCH_RXF4            = 4,
+        MCP2515_FILTERMATCH_RXF5            = 5,
+        MCP2515_FILTERMATCH_RXF0_ROLLOVER   = 6,
+        MCP2515_FILTERMATCH_RXF1_ROLLOVER   = 7
+    } MCP2515_FILTERMATCH_T;
+
+    // MCP2515_RXSTATUS_MSGTYPE values
+    typedef enum {
+        MCP2515_MSGTYPE_STD                 = 0, // standard
+        MCP2515_MSGTYPE_STDRF               = 1, // standard remote frame
+        MCP2515_MSGTYPE_EXT                 = 2, // extended
+        MCP2515_MSGTYPE_EXTRF               = 3  // extended remote frame
+    } MCP2515_MSGTYPE_T;
+
+    // MCP2515_RXSTATUS_RXMSG values
+    typedef enum {
+        MCP2515_RXMSG_NONE                  = 0, // no msg
+        MCP2515_RXMSG_RXB0                  = 1, // msg in rxb0
+        MCP2515_RXMSG_RXB1                  = 2, // msg in rxb1
+        MCP2515_RXMSG_BOTH                  = 3  // msg in both
+    } MCP2515_RXMSG_T;
+
+    // we spell out the SIDL registers as they contain the EXIDE bit.
+    // The others (SIDL, EID0 and EID8 just contain their respective
+    // ID bits.
+    typedef enum {
+        MCP2515_SIDL_EID16                  = 0x01,
+        MCP2515_SIDL_EID17                  = 0x02,
+
+        // 0x04 reserved
+
+        MCP2515_SIDL_EXIDE                  = 0x08,
+
+        // 0x10 reserved
+
+        MCP2515_SIDL_SID0                   = 0x20,
+        MCP2515_SIDL_SID1                   = 0x40,
+        MCP2515_SIDL_SID2                   = 0x80
+    } MCP2515_SIDL_T;
+
+    // An enum to specify one of the 3 TX buffers
+    typedef enum {
+        MCP2515_TX_BUFFER0                  = 0,
+        MCP2515_TX_BUFFER1                  = 1,
+        MCP2515_TX_BUFFER2                  = 2,
+        // special value indicating no buffers
+        MCP2515_TX_NO_BUFFERS               = 255
+    } MCP2515_TX_BUFFER_T;
+
+    // An enum to specify one of the 2 rx buffers
+    typedef enum {
+        MCP2515_RX_BUFFER0                  = 0,
+        MCP2515_RX_BUFFER1                  = 1
+    } MCP2515_RX_BUFFER_T;
+
+    // An enum to specify one of the 6 rx filters
+    typedef enum {
+        MCP2515_RX_FILTER0                  = 0,
+        MCP2515_RX_FILTER1                  = 1,
+        MCP2515_RX_FILTER2                  = 2,
+        MCP2515_RX_FILTER3                  = 3,
+        MCP2515_RX_FILTER4                  = 4,
+        MCP2515_RX_FILTER5                  = 5
+    } MCP2515_RX_FILTER_T;
+
+    // An enum to specify one of the 2 rx masks
+    typedef enum {
+        MCP2515_RX_MASK0                    = 0,
+        MCP2515_RX_MASK1                    = 1
+    } MCP2515_RX_MASK_T;
+
+
+#ifdef __cplusplus
+}
+#endif

src/mcp2515/pyupm_mcp2515.i

@@ -0,0 +1,19 @@
+// Include doxygen-generated documentation
+%include "pyupm_doxy2swig.i"
+%module pyupm_mcp2515
+%include "../upm.i"
+%include "cpointer.i"
+%include "std_string.i"
+%include "../carrays_uint8_t.i"
+
+%include "stdint.i"
+
+%feature("autodoc", "3");
+
+%pointer_functions(float, floatp);
+
+%include "mcp2515_regs.h"
+%include "mcp2515.hpp"
+%{
+    #include "mcp2515.hpp"
+%}