Alfred Lind-Anderton / Mbed 2 deprecated CAN_Hello_XAVIER

Using CAN bus with (not just NUCLEO) mbed boards

Dependencies:   mbed CANMsg

main.cpp@7:883da97339ab, 2019-02-05 (annotated)

Committer:
hudakz
Date:
Tue Feb 05 15:01:00 2019 +0000
Revision:
7:883da97339ab
Parent:
6:c893b98fc2b5
Child:
8:c65afde7f7f5
Modified.

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 1:6f8ffb2c2dd7 10 * For more details see the wiki page <https://developer.mbed.org/users/hudakz/code/CAN_Hello/>
hudakz 0:1b9561cd1c36 11 *
hudakz 4:09d564da0e24 12 * NOTE: When using an STM32F103C8T6 board uncomment line 22 and import the mbed-STM32F103C8T6 library
hudakz 0:1b9561cd1c36 13 *
hudakz 1:6f8ffb2c2dd7 14 * The same code is used for both mbed boards, but:
hudakz 0:1b9561cd1c36 15 * For board #1 compile the example without any change.
hudakz 3:87a128bca8f5 16 * For board #2 comment out line 21 before compiling
hudakz 0:1b9561cd1c36 17 *
hudakz 3:87a128bca8f5 18 * Once the binaries have been downloaded to the boards reset both boards at the same time.
hudakz 0:1b9561cd1c36 19 *
hudakz 0:1b9561cd1c36 20 */
hudakz 1:6f8ffb2c2dd7 21
hudakz 5:37ab4112d547 22 //#define TARGET_STM32F103C8T6 1 // uncomment this line when using STM32F103C8T6 boards!
hudakz 4:09d564da0e24 23
hudakz 4:09d564da0e24 24 #define BOARD1 1 // comment out this line when compiling for board #2
hudakz 0:1b9561cd1c36 25
hudakz 0:1b9561cd1c36 26 #if defined(TARGET_STM32F103C8T6)
hudakz 7:883da97339ab 27 #define LED_PIN PC_13
hudakz 7:883da97339ab 28 #define USBTX PA_2
hudakz 7:883da97339ab 29 #define USBRX PA_3
hudakz 7:883da97339ab 30 const int OFF = 1;
hudakz 7:883da97339ab 31 const int ON = 0;
hudakz 0:1b9561cd1c36 32 #else
hudakz 7:883da97339ab 33 #define LED_PIN LED1
hudakz 7:883da97339ab 34 const int OFF = 0;
hudakz 7:883da97339ab 35 const int ON = 1;
hudakz 0:1b9561cd1c36 36 #endif
hudakz 7:883da97339ab 37
hudakz 0:1b9561cd1c36 38 #if defined(BOARD1)
hudakz 7:883da97339ab 39 const unsigned int RX_ID = 0x100;
hudakz 7:883da97339ab 40 const unsigned int TX_ID = 0x101;
hudakz 0:1b9561cd1c36 41 #else
hudakz 7:883da97339ab 42 const unsigned int RX_ID = 0x101;
hudakz 7:883da97339ab 43 const unsigned int TX_ID = 0x100;
hudakz 0:1b9561cd1c36 44 #endif
hudakz 7:883da97339ab 45
hudakz 0:1b9561cd1c36 46 #include "mbed.h"
hudakz 0:1b9561cd1c36 47 #include "CANMsg.h"
hudakz 0:1b9561cd1c36 48
hudakz 3:87a128bca8f5 49 Serial pc(USBTX, USBRX);
hudakz 4:09d564da0e24 50 CAN can(PB_8, PB_9); // CAN Rx pin name, CAN Tx pin name
hudakz 0:1b9561cd1c36 51 CANMsg rxMsg;
hudakz 0:1b9561cd1c36 52 CANMsg txMsg;
hudakz 0:1b9561cd1c36 53 DigitalOut led(LED_PIN);
hudakz 0:1b9561cd1c36 54 Timer timer;
hudakz 0:1b9561cd1c36 55 uint8_t counter = 0;
hudakz 0:1b9561cd1c36 56 AnalogIn analogIn(A0);
hudakz 0:1b9561cd1c36 57 float voltage;
hudakz 0:1b9561cd1c36 58
hudakz 0:1b9561cd1c36 59 /**
hudakz 0:1b9561cd1c36 60 * @brief Prints CAN msg to PC's serial terminal
hudakz 2:6546e4a2d593 61 * @note
hudakz 1:6f8ffb2c2dd7 62 * @param CANMessage to print
hudakz 3:87a128bca8f5 63 * @retval
hudakz 0:1b9561cd1c36 64 */
hudakz 5:37ab4112d547 65 void printMsg(CANMessage& msg)
hudakz 5:37ab4112d547 66 {
hudakz 0:1b9561cd1c36 67 pc.printf(" ID = 0x%.3x\r\n", msg.id);
hudakz 0:1b9561cd1c36 68 pc.printf(" Type = %d\r\n", msg.type);
hudakz 0:1b9561cd1c36 69 pc.printf(" Format = %d\r\n", msg.format);
hudakz 0:1b9561cd1c36 70 pc.printf(" Length = %d\r\n", msg.len);
hudakz 0:1b9561cd1c36 71 pc.printf(" Data =");
hudakz 0:1b9561cd1c36 72 for(int i = 0; i < msg.len; i++)
hudakz 0:1b9561cd1c36 73 pc.printf(" 0x%.2X", msg.data[i]);
hudakz 0:1b9561cd1c36 74 pc.printf("\r\n");
hudakz 0:1b9561cd1c36 75 }
hudakz 0:1b9561cd1c36 76
hudakz 0:1b9561cd1c36 77 /**
hudakz 5:37ab4112d547 78 * @brief Handles received CAN messages
hudakz 5:37ab4112d547 79 * @note Called on CAN msg received interrupt.
hudakz 5:37ab4112d547 80 * @param
hudakz 5:37ab4112d547 81 * @retval
hudakz 5:37ab4112d547 82 */
hudakz 5:37ab4112d547 83 void onCanReceived(void)
hudakz 5:37ab4112d547 84 {
hudakz 5:37ab4112d547 85 can.read(rxMsg);
hudakz 5:37ab4112d547 86 printMsg(rxMsg);
hudakz 5:37ab4112d547 87
hudakz 5:37ab4112d547 88 if (rxMsg.id == RX_ID) {
hudakz 5:37ab4112d547 89 // extract data from the received CAN message
hudakz 5:37ab4112d547 90 // in the same order as was added on the transmitter side
hudakz 5:37ab4112d547 91 rxMsg >> counter;
hudakz 5:37ab4112d547 92 rxMsg >> voltage;
hudakz 5:37ab4112d547 93 pc.printf(" counter = %d\r\n", counter);
hudakz 5:37ab4112d547 94 pc.printf(" voltage = %e V\r\n", voltage);
hudakz 5:37ab4112d547 95 }
hudakz 5:37ab4112d547 96 timer.start(); // to transmit next message
hudakz 5:37ab4112d547 97 }
hudakz 5:37ab4112d547 98
hudakz 5:37ab4112d547 99
hudakz 5:37ab4112d547 100 /**
hudakz 0:1b9561cd1c36 101 * @brief Main
hudakz 0:1b9561cd1c36 102 * @note
hudakz 0:1b9561cd1c36 103 * @param
hudakz 0:1b9561cd1c36 104 * @retval
hudakz 0:1b9561cd1c36 105 */
hudakz 0:1b9561cd1c36 106 int main(void)
hudakz 0:1b9561cd1c36 107 {
hudakz 1:6f8ffb2c2dd7 108 pc.baud(9600); // set Serial speed
hudakz 1:6f8ffb2c2dd7 109 can.frequency(1000000); // set bit rate to 1Mbps
hudakz 5:37ab4112d547 110 can.filter(RX_ID, 0xFFF, CANStandard, 0); // set filter #0 to accept only standard messages with ID == RX_ID
hudakz 5:37ab4112d547 111 can.attach(onCanReceived); // attach ISP
hudakz 5:37ab4112d547 112
hudakz 0:1b9561cd1c36 113 #if defined(BOARD1)
hudakz 1:6f8ffb2c2dd7 114 led = ON; // turn the LED on
hudakz 1:6f8ffb2c2dd7 115 timer.start(); // start timer
hudakz 1:6f8ffb2c2dd7 116 pc.printf("CAN_Hello board #1\r\n");
hudakz 0:1b9561cd1c36 117 #else
hudakz 0:1b9561cd1c36 118 led = OFF; // turn LED off
hudakz 1:6f8ffb2c2dd7 119 pc.printf("CAN_Hello board #2\r\n");
hudakz 0:1b9561cd1c36 120 #endif
hudakz 0:1b9561cd1c36 121 while(1) {
hudakz 3:87a128bca8f5 122 if(timer.read_ms() >= 1000) { // check for timeout
hudakz 3:87a128bca8f5 123 timer.stop(); // stop timer
hudakz 3:87a128bca8f5 124 timer.reset(); // reset timer
hudakz 3:87a128bca8f5 125 counter++; // increment counter
hudakz 5:37ab4112d547 126 voltage = analogIn * 3.3f; // read the small drift voltage from analog input
hudakz 3:87a128bca8f5 127 txMsg.clear(); // clear Tx message storage
hudakz 3:87a128bca8f5 128 txMsg.id = TX_ID; // set ID
hudakz 5:37ab4112d547 129 // append data (total data length must not exceed 8 bytes!)
hudakz 5:37ab4112d547 130 txMsg << counter; // one byte
hudakz 5:37ab4112d547 131 txMsg << voltage; // four bytes
hudakz 5:37ab4112d547 132
hudakz 3:87a128bca8f5 133 if(can.write(txMsg)) { // transmit message
hudakz 3:87a128bca8f5 134 led = OFF; // turn the LED off
hudakz 0:1b9561cd1c36 135 pc.printf("-------------------------------------\r\n");
hudakz 0:1b9561cd1c36 136 pc.printf("CAN message sent\r\n");
hudakz 0:1b9561cd1c36 137 printMsg(txMsg);
hudakz 0:1b9561cd1c36 138 pc.printf(" counter = %d\r\n", counter);
hudakz 0:1b9561cd1c36 139 pc.printf(" voltage = %e V\r\n", voltage);
hudakz 0:1b9561cd1c36 140 }
hudakz 0:1b9561cd1c36 141 else
hudakz 0:1b9561cd1c36 142 pc.printf("Transmission error\r\n");
hudakz 0:1b9561cd1c36 143 }
hudakz 0:1b9561cd1c36 144 }
hudakz 0:1b9561cd1c36 145 }