/* * Author: Jon Trulson * 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 #include #include #include #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; }