ADVES / Mbed 2 deprecated CAN_Hello

example showing how to use the mbed CAN API

Dependencies:   mbed CANMsg

main.cpp@8:c65afde7f7f5, 2019-02-05 (annotated)

Committer:
hudakz
Date:
Tue Feb 05 19:03:26 2019 +0000
Revision:
8:c65afde7f7f5
Parent:
7:883da97339ab
Child:
9:3211e88e30a5
Updated.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
hudakz 0:1b9561cd1c36 1 /*
hudakz 1:6f8ffb2c2dd7 2 * An example showing how to use the mbed CAN API:
hudakz 0:1b9561cd1c36 3 *
hudakz 3:87a128bca8f5 4 * Two affordable (about $2 on ebay) STM32F103C8T6 boards (20kB SRAM, 64kB Flash),
hudakz 1:6f8ffb2c2dd7 5 * (see [https://developer.mbed.org/users/hudakz/code/STM32F103C8T6_Hello/] for more details)
hudakz 0:1b9561cd1c36 6 * are connected to the same CAN bus via transceivers (MCP2551 or TJA1040, or etc.).
hudakz 0:1b9561cd1c36 7 * CAN transceivers are not part of NUCLEO boards, therefore must be added by you.
hudakz 0:1b9561cd1c36 8 * Remember also that CAN bus (even a short one) must be terminated with 120 Ohm resitors at both ends.
hudakz 1:6f8ffb2c2dd7 9 *
hudakz 0:1b9561cd1c36 10 *
hudakz 1:6f8ffb2c2dd7 11 * The same code is used for both mbed boards, but:
hudakz 0:1b9561cd1c36 12 * For board #1 compile the example without any change.
hudakz 3:87a128bca8f5 13 * For board #2 comment out line 21 before compiling
hudakz 0:1b9561cd1c36 14 *
hudakz 3:87a128bca8f5 15 * Once the binaries have been downloaded to the boards reset both boards at the same time.
hudakz 0:1b9561cd1c36 16 *
hudakz 0:1b9561cd1c36 17 */
hudakz 1:6f8ffb2c2dd7 18
hudakz 8:c65afde7f7f5 19 //#define TARGET_STM32F103C8T6 1 // uncomment this line to use STM32F103C8T6 boards
hudakz 4:09d564da0e24 20
hudakz 4:09d564da0e24 21 #define BOARD1 1 // comment out this line when compiling for board #2
hudakz 0:1b9561cd1c36 22
hudakz 0:1b9561cd1c36 23 #if defined(TARGET_STM32F103C8T6)
hudakz 7:883da97339ab 24 #define LED_PIN PC_13
hudakz 7:883da97339ab 25 #define USBTX PA_2
hudakz 7:883da97339ab 26 #define USBRX PA_3
hudakz 7:883da97339ab 27 const int OFF = 1;
hudakz 7:883da97339ab 28 const int ON = 0;
hudakz 0:1b9561cd1c36 29 #else
hudakz 7:883da97339ab 30 #define LED_PIN LED1
hudakz 7:883da97339ab 31 const int OFF = 0;
hudakz 7:883da97339ab 32 const int ON = 1;
hudakz 0:1b9561cd1c36 33 #endif
hudakz 7:883da97339ab 34
hudakz 0:1b9561cd1c36 35 #if defined(BOARD1)
hudakz 7:883da97339ab 36 const unsigned int RX_ID = 0x100;
hudakz 7:883da97339ab 37 const unsigned int TX_ID = 0x101;
hudakz 0:1b9561cd1c36 38 #else
hudakz 7:883da97339ab 39 const unsigned int RX_ID = 0x101;
hudakz 7:883da97339ab 40 const unsigned int TX_ID = 0x100;
hudakz 0:1b9561cd1c36 41 #endif
hudakz 7:883da97339ab 42
hudakz 0:1b9561cd1c36 43 #include "mbed.h"
hudakz 0:1b9561cd1c36 44 #include "CANMsg.h"
hudakz 0:1b9561cd1c36 45
hudakz 3:87a128bca8f5 46 Serial pc(USBTX, USBRX);
hudakz 4:09d564da0e24 47 CAN can(PB_8, PB_9); // CAN Rx pin name, CAN Tx pin name
hudakz 0:1b9561cd1c36 48 CANMsg rxMsg;
hudakz 0:1b9561cd1c36 49 CANMsg txMsg;
hudakz 0:1b9561cd1c36 50 DigitalOut led(LED_PIN);
hudakz 0:1b9561cd1c36 51 Timer timer;
hudakz 0:1b9561cd1c36 52 uint8_t counter = 0;
hudakz 0:1b9561cd1c36 53 AnalogIn analogIn(A0);
hudakz 0:1b9561cd1c36 54 float voltage;
hudakz 0:1b9561cd1c36 55
hudakz 0:1b9561cd1c36 56 /**
hudakz 8:c65afde7f7f5 57 * @brief Prints CAN message to PC's serial terminal
hudakz 2:6546e4a2d593 58 * @note
hudakz 1:6f8ffb2c2dd7 59 * @param CANMessage to print
hudakz 3:87a128bca8f5 60 * @retval
hudakz 0:1b9561cd1c36 61 */
hudakz 5:37ab4112d547 62 void printMsg(CANMessage& msg)
hudakz 5:37ab4112d547 63 {
hudakz 0:1b9561cd1c36 64 pc.printf(" ID = 0x%.3x\r\n", msg.id);
hudakz 0:1b9561cd1c36 65 pc.printf(" Type = %d\r\n", msg.type);
hudakz 0:1b9561cd1c36 66 pc.printf(" Format = %d\r\n", msg.format);
hudakz 0:1b9561cd1c36 67 pc.printf(" Length = %d\r\n", msg.len);
hudakz 0:1b9561cd1c36 68 pc.printf(" Data =");
hudakz 0:1b9561cd1c36 69 for(int i = 0; i < msg.len; i++)
hudakz 0:1b9561cd1c36 70 pc.printf(" 0x%.2X", msg.data[i]);
hudakz 0:1b9561cd1c36 71 pc.printf("\r\n");
hudakz 0:1b9561cd1c36 72 }
hudakz 0:1b9561cd1c36 73
hudakz 0:1b9561cd1c36 74 /**
hudakz 5:37ab4112d547 75 * @brief Handles received CAN messages
hudakz 8:c65afde7f7f5 76 * @note Called on 'CAN message received' interrupt.
hudakz 5:37ab4112d547 77 * @param
hudakz 5:37ab4112d547 78 * @retval
hudakz 5:37ab4112d547 79 */
hudakz 5:37ab4112d547 80 void onCanReceived(void)
hudakz 5:37ab4112d547 81 {
hudakz 5:37ab4112d547 82 can.read(rxMsg);
hudakz 5:37ab4112d547 83 printMsg(rxMsg);
hudakz 5:37ab4112d547 84
hudakz 5:37ab4112d547 85 if (rxMsg.id == RX_ID) {
hudakz 5:37ab4112d547 86 // extract data from the received CAN message
hudakz 8:c65afde7f7f5 87 // in the same order as it was added on the transmitter side
hudakz 5:37ab4112d547 88 rxMsg >> counter;
hudakz 5:37ab4112d547 89 rxMsg >> voltage;
hudakz 5:37ab4112d547 90 pc.printf(" counter = %d\r\n", counter);
hudakz 5:37ab4112d547 91 pc.printf(" voltage = %e V\r\n", voltage);
hudakz 5:37ab4112d547 92 }
hudakz 8:c65afde7f7f5 93 timer.start(); // to transmit next message in main
hudakz 5:37ab4112d547 94 }
hudakz 5:37ab4112d547 95
hudakz 5:37ab4112d547 96
hudakz 5:37ab4112d547 97 /**
hudakz 0:1b9561cd1c36 98 * @brief Main
hudakz 0:1b9561cd1c36 99 * @note
hudakz 0:1b9561cd1c36 100 * @param
hudakz 0:1b9561cd1c36 101 * @retval
hudakz 0:1b9561cd1c36 102 */
hudakz 0:1b9561cd1c36 103 int main(void)
hudakz 0:1b9561cd1c36 104 {
hudakz 8:c65afde7f7f5 105 pc.baud(9600); // set serial speed
hudakz 8:c65afde7f7f5 106 can.frequency(1000000); // set CAN bit rate to 1Mbps
hudakz 5:37ab4112d547 107 can.filter(RX_ID, 0xFFF, CANStandard, 0); // set filter #0 to accept only standard messages with ID == RX_ID
hudakz 8:c65afde7f7f5 108 can.attach(onCanReceived); // attach ISR to handle received messages
hudakz 5:37ab4112d547 109
hudakz 0:1b9561cd1c36 110 #if defined(BOARD1)
hudakz 1:6f8ffb2c2dd7 111 led = ON; // turn the LED on
hudakz 1:6f8ffb2c2dd7 112 timer.start(); // start timer
hudakz 1:6f8ffb2c2dd7 113 pc.printf("CAN_Hello board #1\r\n");
hudakz 0:1b9561cd1c36 114 #else
hudakz 0:1b9561cd1c36 115 led = OFF; // turn LED off
hudakz 1:6f8ffb2c2dd7 116 pc.printf("CAN_Hello board #2\r\n");
hudakz 0:1b9561cd1c36 117 #endif
hudakz 0:1b9561cd1c36 118 while(1) {
hudakz 3:87a128bca8f5 119 if(timer.read_ms() >= 1000) { // check for timeout
hudakz 3:87a128bca8f5 120 timer.stop(); // stop timer
hudakz 3:87a128bca8f5 121 timer.reset(); // reset timer
hudakz 3:87a128bca8f5 122 counter++; // increment counter
hudakz 5:37ab4112d547 123 voltage = analogIn * 3.3f; // read the small drift voltage from analog input
hudakz 3:87a128bca8f5 124 txMsg.clear(); // clear Tx message storage
hudakz 3:87a128bca8f5 125 txMsg.id = TX_ID; // set ID
hudakz 5:37ab4112d547 126 // append data (total data length must not exceed 8 bytes!)
hudakz 5:37ab4112d547 127 txMsg << counter; // one byte
hudakz 5:37ab4112d547 128 txMsg << voltage; // four bytes
hudakz 5:37ab4112d547 129
hudakz 3:87a128bca8f5 130 if(can.write(txMsg)) { // transmit message
hudakz 3:87a128bca8f5 131 led = OFF; // turn the LED off
hudakz 0:1b9561cd1c36 132 pc.printf("-------------------------------------\r\n");
hudakz 0:1b9561cd1c36 133 pc.printf("CAN message sent\r\n");
hudakz 0:1b9561cd1c36 134 printMsg(txMsg);
hudakz 0:1b9561cd1c36 135 pc.printf(" counter = %d\r\n", counter);
hudakz 0:1b9561cd1c36 136 pc.printf(" voltage = %e V\r\n", voltage);
hudakz 0:1b9561cd1c36 137 }
hudakz 0:1b9561cd1c36 138 else
hudakz 0:1b9561cd1c36 139 pc.printf("Transmission error\r\n");
hudakz 0:1b9561cd1c36 140 }
hudakz 0:1b9561cd1c36 141 }
hudakz 0:1b9561cd1c36 142 }