MPR121: Added C Source

Signed-off-by: Abhishek Malik <abhishek.malik@intel.com>

src/mpr121/CMakeLists.txt

@@ -1,5 +1,9 @@
-set (libname "mpr121")
+upm_mixed_module_init (NAME mpr121
-set (libdescription "upm mpr121 I2C Touch module")
+    DESCRIPTION "upm mpr121sensor module"
-set (module_src ${libname}.cxx)
+    C_HDR mpr121.h
-set (module_hpp ${libname}.hpp)
+    C_SRC mpr121.c
-upm_module_init()
+    CPP_HDR mpr121.hpp
+    CPP_SRC mpr121.cxx
+    FTI_SRC mpr121_fti.c
+    CPP_WRAPS_C
+    REQUIRES mraa)

src/mpr121/mpr121.c

@@ -0,0 +1,205 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ *         Abhishek Malik <abhishek.malik@intel.com>
+ * Copyright (c) 2014 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 "mpr121.h"
+
+mpr121_context mpr121_init(int bus, uint8_t address){
+    mpr121_context dev = (mpr121_context)malloc(sizeof(struct _mpr121_context));
+
+    if (!dev)
+      return NULL;
+
+    dev->bus = bus;
+    dev->address = address;
+    dev->i2c = mraa_i2c_init(dev->bus);
+
+    if(dev->i2c == NULL){
+        free(dev);
+        return NULL;
+    }
+
+    if (mraa_i2c_address(dev->i2c, dev->address) != MRAA_SUCCESS){
+        free(dev);
+        printf("error using i2c address: %x\n", dev->address);
+        return NULL;
+    }
+
+    dev->over_current_fault = false;
+    return dev;
+}
+
+void mpr121_close(mpr121_context dev){
+    mraa_i2c_stop(dev->i2c);
+    free(dev);
+}
+
+upm_result_t mpr121_write_bytes(mpr121_context dev, uint8_t reg,
+                                uint8_t *buffer, int len){
+    if(!len || !buffer)
+        return UPM_ERROR_INVALID_SIZE;
+
+    // create a buffer 1 byte larger than the supplied buffer,
+    // store the register in the first byte
+    uint8_t buf2[len + 1];
+    buf2[0] = reg;
+
+    // copy in the buffer after the reg byte
+
+    int i;
+    for(i=1; i<(len + 1); i++)
+        buf2[i] = buffer[i-1];
+
+    if(mraa_i2c_address(dev->i2c, dev->address) != MRAA_SUCCESS){
+        printf("write byte error address\n");
+        return UPM_ERROR_OPERATION_FAILED;
+    }
+
+    if(mraa_i2c_write(dev->i2c, buf2, len+1) != MRAA_SUCCESS){
+        printf("write byte error while writing\n");
+        return UPM_ERROR_OPERATION_FAILED;
+    }
+    return UPM_SUCCESS;
+}
+
+upm_result_t mpr121_read_bytes(mpr121_context dev, uint8_t reg,
+                               uint8_t *buffer, int len){
+    if(!len || !buffer)
+        return UPM_ERROR_INVALID_SIZE;
+
+    // The usual m_i2c.read() does not work here, so we need to
+    // read each byte individually.
+    int i;
+    for (i=0; i<len; i++)
+        buffer[i] = mraa_i2c_read_byte_data(dev->i2c, reg+i);
+
+    return UPM_SUCCESS;
+}
+
+upm_result_t mpr121_read_buttons(mpr121_context dev, uint32_t* states,
+                                     int num){
+    int len = 2;
+    uint8_t buffer[2];
+
+    // read in the 2 bytes at register 0x00-0x01, and setup the member
+    // variables accordingly.
+    mpr121_read_bytes(dev, 0x00, buffer, len);
+
+    *states = (buffer[0] | ((buffer[1] & 0x1f) << 8));
+    if (buffer[1] & 0x80)
+        dev->over_current_fault = true;
+    else
+        dev->over_current_fault = false;
+
+    return UPM_SUCCESS;
+}
+
+upm_result_t mpr121_config_an3944(mpr121_context dev){
+    // Configure the mpr121 chip as recommended in the AN3944 MPR121
+    // Quick Start Guide
+    // First, turn off all electrodes by zeroing out the Electrode Configuration
+    // register.
+    // If this one fails, it's unlikely any of the others will succeed.
+    uint8_t eleConf = 0x00;
+    if (mpr121_write_bytes(dev, 0x5e, &eleConf, 1) != UPM_SUCCESS){
+        printf("write to electrode configuration register failed\n");
+        return UPM_ERROR_OPERATION_FAILED;
+    }
+
+    // Section A
+    // Filtering when data is greater than baseline
+    // regs 0x2b-0x2e
+
+    uint8_t sectA[] = {0x01, 0x01, 0x00, 0x00};
+    if (mpr121_write_bytes(dev, 0x2b, sectA, 4) != UPM_SUCCESS){
+        printf("write to section a failed\n");
+        return UPM_ERROR_OPERATION_FAILED;
+    }
+
+    // Section B
+    // Filtering when data is less than baseline
+    // regs 0x2f-0x32
+
+    uint8_t sectB[] = {0x01, 0x01, 0xff, 0x02};
+    if (mpr121_write_bytes(dev, 0x2f, sectB, 4) != UPM_SUCCESS){
+        printf("write to section b failed\n");
+        return UPM_ERROR_OPERATION_FAILED;
+    }
+
+    // Section C
+    // Touch Threshold/Release registers, ELE0-ELE11
+    // regs 0x41-0x58
+    //                    __T_  __R_
+    uint8_t sectC[] =  {0x0f, 0x0a,
+        0x0f, 0x0a,
+        0x0f, 0x0a,
+        0x0f, 0x0a,
+        0x0f, 0x0a,
+        0x0f, 0x0a,
+        0x0f, 0x0a,
+        0x0f, 0x0a,
+        0x0f, 0x0a,
+        0x0f, 0x0a,
+        0x0f, 0x0a,
+        0x0f, 0x0a};
+
+    if (mpr121_write_bytes(dev, 0x41, sectC, 24) != UPM_SUCCESS){
+        printf("failed to configure touch threshold/release regs\n");
+        return UPM_ERROR_OPERATION_FAILED;
+    }
+
+    // Section D
+    // Filter configuration
+    // reg 0x5d
+    uint8_t filterConf = 0x04;
+    if (mpr121_write_bytes(dev, 0x5d, &filterConf, 1) != UPM_SUCCESS){
+        printf("unable to configure filters\n");
+        return UPM_ERROR_OPERATION_FAILED;
+    }
+
+    // Section F
+    // Autoconfiguration registers
+    // regs 0x7b-0x7f
+    uint8_t sectF0 = 0x0b;
+    if (mpr121_write_bytes(dev, 0x7b, &sectF0, 1) != UPM_SUCCESS){
+        printf("unable to configure auto config regs\n");
+        return UPM_ERROR_OPERATION_FAILED;
+    }
+
+    uint8_t sectF1[] = {0x9c, 0x65, 0x8c};
+    if (mpr121_write_bytes(dev, 0x7d, sectF1, 3) != UPM_SUCCESS){
+        return UPM_ERROR_OPERATION_FAILED;
+    }
+
+    // Section E - this one must be set last, and switches to run mode
+    // Enable all 12 electrodes, and set a pre-calibration to avoid
+    // excessive calibration delay on startup.
+    // reg 0x5e
+    eleConf = 0x8c;
+    if (mpr121_write_bytes(dev, 0x5e, &eleConf, 3) != UPM_SUCCESS){
+        return UPM_ERROR_OPERATION_FAILED;
+    }
+
+    return UPM_SUCCESS;
+}

src/mpr121/mpr121.h

@@ -0,0 +1,111 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ *         Abhishek Malik <abhishek.malik@intel.com>
+ * Copyright (c) 2014 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.
+ */
+
+#ifndef MPR121_H_
+#define MPR121_H_
+
+#include <stdint.h>
+#include "upm.h"
+#include "mraa/i2c.h"
+
+#define MPR121_I2C_BUS     0
+#define MPR121_DEFAULT_I2C_ADDR    0x5a
+
+/**
+ * device context
+ */
+typedef struct _mpr121_context {
+    mraa_i2c_context    i2c;
+    int                 bus;
+    uint8_t             address;
+    uint8_t             over_current_fault;
+} *mpr121_context;
+
+/**
+ * MPR121 Init function
+ *
+ * @param bus i2c bus
+ * @param address i2c address of the sensor
+ * @return void* pointer to the sensor struct
+ */
+mpr121_context mpr121_init(int bus, uint8_t address);
+
+/**
+ * MPR121 Close function
+ *
+ * @param dev pointer to sensor struct
+ */
+void mpr121_close(mpr121_context dev);
+
+/**
+ * Sets up a default configuration, based on Application Note 3944
+ * (AN3944):
+ * http://cache.freescale.com/files/sensors/doc/app_note/AN3944.pdf
+ *
+ * After configuration, the sensor is left in the run state.
+ *
+ * @param dev pointer to the sensor struct
+ * @return upm_result_t UPM success/error code
+ */
+upm_result_t mpr121_config_an3944(mpr121_context dev);
+
+/**
+ * Function to read the individual button values
+ *
+ * @param dev pointer to the sensor struct
+ * @param states Pointer to store the states of the individual buttons
+ * @param num used to retrieve the state of a particular button
+ * @return upm_result_t UPM success/error code
+ */
+upm_result_t mpr121_read_buttons(mpr121_context dev, uint32_t* states, int num);
+
+/**
+ * Function used to write multiple bytes to the i2c bus
+ *
+ * @param dev sensor struct
+ * @param reg i2c register to read from
+ * @param *buffer pointer that contains the values that have to be
+ * written to the registers
+ * @param len length of the values that have to be written to the regs
+ * @return upm_result_t UPM success/error code
+ */
+upm_result_t mpr121_write_bytes(mpr121_context dev, uint8_t reg,
+                                uint8_t *buffer, int len);
+
+/**
+ * Function used to read multiple bytes from the i2c bus
+ *
+ * @param dev sensor struct
+ * @param reg i2c register to read from
+ * @param *buffer pointer that contains the values that have been
+ * read from the registers
+ * @param len length of the values that have to be read
+ * @return upm_result_t UPM success/error code
+ */
+
+upm_result_t mpr121_read_bytes(mpr121_context dev, uint8_t reg,
+                               uint8_t *buffer, int len);
+
+#endif /* MPR121_H_ */

src/mpr121/mpr121_fti.c

@@ -0,0 +1,75 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ *         Abhishek Malik <abhishek.malik@intel.com>
+ * Copyright (c) 2014 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 "mpr121.h"
+#include "upm_fti.h"
+
+/** 
+ * This file implements the Function Table Interface (FTI) for this sensor
+ */
+
+const char upm_mpr121_name[] = "MPR121";
+const char upm_mpr121_description[] = "MPR121 Touch Sensor";
+const upm_protocol_t upm_mpr121_protocol[] = {UPM_I2C};
+const upm_sensor_t upm_mpr121_category[] = {UPM_SWITCH};
+
+// forward declarationss
+const upm_sensor_descriptor_t upm_mpr121_get_descriptor ();
+const void* upm_mpr121_get_ft(upm_sensor_t sensor_type);
+void* upm_mpr121_init_name();
+void upm_mpr121_close(void* dev);
+
+const upm_sensor_descriptor_t upm_mpr121_get_descriptor (){
+    upm_sensor_descriptor_t usd;
+    usd.name = upm_mpr121_name;
+    usd.description = upm_mpr121_description;
+    usd.protocol_size = 1;
+    usd.protocol = upm_mpr121_protocol;
+    usd.category_size = 1;
+    usd.category = upm_mpr121_category;
+    return usd;
+}
+
+static const upm_sensor_ft ft =
+{
+    .upm_sensor_init_name = &upm_mpr121_init_name,
+    .upm_sensor_close = &upm_mpr121_close,
+    .upm_sensor_get_descriptor = &upm_mpr121_get_descriptor
+};
+
+const void* upm_mpr121_get_ft(upm_sensor_t sensor_type){
+    if(sensor_type == UPM_SENSOR){
+        return &ft;
+    }
+    return NULL;
+}
+
+void* upm_mpr121_init_name(){
+    return NULL;
+}
+
+void upm_mpr121_close(void* dev){
+    mpr121_close((mpr121_context)dev);
+}