Using CAN bus with (not just NUCLEO) mbed boards support Cortex-M0
Fork of CAN_Hello by
main.cpp@3:36b034f320b6, 2018-03-22 (annotated)
- Committer:
- szqt
- Date:
- Thu Mar 22 13:41:08 2018 +0000
- Revision:
- 3:36b034f320b6
- Parent:
- 2:6546e4a2d593
Support NUCLEO-F091RC (Cortex-M0)
Who changed what in which revision?
User | Revision | Line number | New 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 | 0:1b9561cd1c36 | 4 | * Two affordable (less than $3 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 | 1:6f8ffb2c2dd7 | 12 | * NOTE: If you'd like to use an STM32F103C8T6 board uncomment line 23 |
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 | 1:6f8ffb2c2dd7 | 16 | * For board #2 comment out line 23 before compiling |
hudakz | 0:1b9561cd1c36 | 17 | * |
hudakz | 0:1b9561cd1c36 | 18 | * Once the binaries have been downloaded to the boards reset board #1. |
hudakz | 0:1b9561cd1c36 | 19 | * |
hudakz | 0:1b9561cd1c36 | 20 | */ |
hudakz | 1:6f8ffb2c2dd7 | 21 | #define BOARD1 1 // comment out this line when compiling for board #2 |
hudakz | 1:6f8ffb2c2dd7 | 22 | |
hudakz | 1:6f8ffb2c2dd7 | 23 | //#define TARGET_STM32F103C8T6 1 // uncomment this line when using STM32F103C8T6 boards! |
hudakz | 0:1b9561cd1c36 | 24 | |
hudakz | 0:1b9561cd1c36 | 25 | #if defined(TARGET_STM32F103C8T6) |
hudakz | 0:1b9561cd1c36 | 26 | #include "stm32f103c8t6.h" |
hudakz | 0:1b9561cd1c36 | 27 | #define LED_PIN PC_13 |
hudakz | 0:1b9561cd1c36 | 28 | const int OFF = 1; |
hudakz | 0:1b9561cd1c36 | 29 | const int ON = 0; |
hudakz | 0:1b9561cd1c36 | 30 | #else |
hudakz | 0:1b9561cd1c36 | 31 | #define LED_PIN LED1 |
hudakz | 0:1b9561cd1c36 | 32 | const int OFF = 0; |
hudakz | 0:1b9561cd1c36 | 33 | const int ON = 1; |
hudakz | 0:1b9561cd1c36 | 34 | #endif |
hudakz | 0:1b9561cd1c36 | 35 | #if defined(BOARD1) |
hudakz | 0:1b9561cd1c36 | 36 | const unsigned int RX_ID = 0x100; |
hudakz | 0:1b9561cd1c36 | 37 | const unsigned int TX_ID = 0x101; |
hudakz | 0:1b9561cd1c36 | 38 | #else |
hudakz | 0:1b9561cd1c36 | 39 | const unsigned int RX_ID = 0x101; |
hudakz | 0:1b9561cd1c36 | 40 | const unsigned int TX_ID = 0x100; |
hudakz | 0:1b9561cd1c36 | 41 | #endif |
hudakz | 0:1b9561cd1c36 | 42 | #include "mbed.h" |
hudakz | 0:1b9561cd1c36 | 43 | #include "CANMsg.h" |
hudakz | 0:1b9561cd1c36 | 44 | |
hudakz | 1:6f8ffb2c2dd7 | 45 | Serial pc(PA_2, PA_3); |
hudakz | 1:6f8ffb2c2dd7 | 46 | CAN can(PA_11, PA_12); // CAN Rx pin name, CAN Tx pin name |
hudakz | 0:1b9561cd1c36 | 47 | CANMsg rxMsg; |
hudakz | 0:1b9561cd1c36 | 48 | CANMsg txMsg; |
hudakz | 0:1b9561cd1c36 | 49 | DigitalOut led(LED_PIN); |
hudakz | 0:1b9561cd1c36 | 50 | Timer timer; |
hudakz | 0:1b9561cd1c36 | 51 | uint8_t counter = 0; |
hudakz | 0:1b9561cd1c36 | 52 | AnalogIn analogIn(A0); |
hudakz | 0:1b9561cd1c36 | 53 | float voltage; |
hudakz | 0:1b9561cd1c36 | 54 | |
hudakz | 0:1b9561cd1c36 | 55 | /** |
hudakz | 0:1b9561cd1c36 | 56 | * @brief Prints CAN msg to PC's serial terminal |
hudakz | 2:6546e4a2d593 | 57 | * @note |
hudakz | 1:6f8ffb2c2dd7 | 58 | * @param CANMessage to print |
hudakz | 0:1b9561cd1c36 | 59 | * @retval none |
hudakz | 0:1b9561cd1c36 | 60 | */ |
hudakz | 1:6f8ffb2c2dd7 | 61 | void printMsg(CANMessage& msg) { |
hudakz | 0:1b9561cd1c36 | 62 | pc.printf(" ID = 0x%.3x\r\n", msg.id); |
hudakz | 0:1b9561cd1c36 | 63 | pc.printf(" Type = %d\r\n", msg.type); |
hudakz | 0:1b9561cd1c36 | 64 | pc.printf(" Format = %d\r\n", msg.format); |
hudakz | 0:1b9561cd1c36 | 65 | pc.printf(" Length = %d\r\n", msg.len); |
hudakz | 0:1b9561cd1c36 | 66 | pc.printf(" Data ="); |
hudakz | 0:1b9561cd1c36 | 67 | for(int i = 0; i < msg.len; i++) |
hudakz | 0:1b9561cd1c36 | 68 | pc.printf(" 0x%.2X", msg.data[i]); |
hudakz | 0:1b9561cd1c36 | 69 | pc.printf("\r\n"); |
hudakz | 0:1b9561cd1c36 | 70 | } |
hudakz | 0:1b9561cd1c36 | 71 | |
hudakz | 0:1b9561cd1c36 | 72 | /** |
hudakz | 0:1b9561cd1c36 | 73 | * @brief Main |
hudakz | 0:1b9561cd1c36 | 74 | * @note |
hudakz | 0:1b9561cd1c36 | 75 | * @param |
hudakz | 0:1b9561cd1c36 | 76 | * @retval |
hudakz | 0:1b9561cd1c36 | 77 | */ |
hudakz | 0:1b9561cd1c36 | 78 | int main(void) |
hudakz | 0:1b9561cd1c36 | 79 | { |
hudakz | 0:1b9561cd1c36 | 80 | #if defined(TARGET_STM32F103C8T6) |
hudakz | 1:6f8ffb2c2dd7 | 81 | confSysClock(); //Configure system clock (72MHz HSE clock, 48MHz USB clock) |
hudakz | 0:1b9561cd1c36 | 82 | #endif |
hudakz | 1:6f8ffb2c2dd7 | 83 | pc.baud(9600); // set Serial speed |
hudakz | 1:6f8ffb2c2dd7 | 84 | can.frequency(1000000); // set bit rate to 1Mbps |
hudakz | 0:1b9561cd1c36 | 85 | #if defined(BOARD1) |
hudakz | 1:6f8ffb2c2dd7 | 86 | led = ON; // turn the LED on |
hudakz | 1:6f8ffb2c2dd7 | 87 | timer.start(); // start timer |
hudakz | 1:6f8ffb2c2dd7 | 88 | pc.printf("CAN_Hello board #1\r\n"); |
hudakz | 0:1b9561cd1c36 | 89 | #else |
hudakz | 0:1b9561cd1c36 | 90 | led = OFF; // turn LED off |
hudakz | 1:6f8ffb2c2dd7 | 91 | pc.printf("CAN_Hello board #2\r\n"); |
hudakz | 0:1b9561cd1c36 | 92 | #endif |
hudakz | 0:1b9561cd1c36 | 93 | while(1) { |
hudakz | 1:6f8ffb2c2dd7 | 94 | if(timer.read_ms() >= 1000) { // check for timeout |
hudakz | 1:6f8ffb2c2dd7 | 95 | timer.stop(); // stop timer |
hudakz | 1:6f8ffb2c2dd7 | 96 | timer.reset(); // reset timer |
hudakz | 1:6f8ffb2c2dd7 | 97 | counter++; // increment counter |
hudakz | 1:6f8ffb2c2dd7 | 98 | voltage = (analogIn * 3.3f) / 4096.0f; // read the small drifting voltage from analog input |
hudakz | 1:6f8ffb2c2dd7 | 99 | txMsg.clear(); // clear Tx message storage |
hudakz | 1:6f8ffb2c2dd7 | 100 | txMsg.id = TX_ID; // set ID |
szqt | 3:36b034f320b6 | 101 | txMsg << voltage << counter;// append data (total data length must be <= 8 bytes!) |
hudakz | 1:6f8ffb2c2dd7 | 102 | if(can.write(txMsg)) { // transmit message |
hudakz | 1:6f8ffb2c2dd7 | 103 | led = OFF; // turn the LED off |
hudakz | 0:1b9561cd1c36 | 104 | pc.printf("-------------------------------------\r\n"); |
hudakz | 0:1b9561cd1c36 | 105 | pc.printf("CAN message sent\r\n"); |
hudakz | 0:1b9561cd1c36 | 106 | printMsg(txMsg); |
hudakz | 0:1b9561cd1c36 | 107 | pc.printf(" counter = %d\r\n", counter); |
hudakz | 0:1b9561cd1c36 | 108 | pc.printf(" voltage = %e V\r\n", voltage); |
hudakz | 0:1b9561cd1c36 | 109 | } |
hudakz | 0:1b9561cd1c36 | 110 | else |
hudakz | 0:1b9561cd1c36 | 111 | pc.printf("Transmission error\r\n"); |
hudakz | 0:1b9561cd1c36 | 112 | } |
hudakz | 0:1b9561cd1c36 | 113 | |
hudakz | 0:1b9561cd1c36 | 114 | if(can.read(rxMsg)) { |
hudakz | 1:6f8ffb2c2dd7 | 115 | led = ON; // turn the LED on |
hudakz | 0:1b9561cd1c36 | 116 | pc.printf("-------------------------------------\r\n"); |
hudakz | 0:1b9561cd1c36 | 117 | pc.printf("CAN message received\r\n"); |
hudakz | 0:1b9561cd1c36 | 118 | printMsg(rxMsg); |
hudakz | 0:1b9561cd1c36 | 119 | |
hudakz | 0:1b9561cd1c36 | 120 | // Filtering performed by software: |
hudakz | 0:1b9561cd1c36 | 121 | if(rxMsg.id == RX_ID) { |
szqt | 3:36b034f320b6 | 122 | rxMsg >> voltage >> counter; // extract data from the received CAN message |
hudakz | 0:1b9561cd1c36 | 123 | pc.printf(" counter = %d\r\n", counter); |
hudakz | 0:1b9561cd1c36 | 124 | pc.printf(" voltage = %e V\r\n", voltage); |
hudakz | 1:6f8ffb2c2dd7 | 125 | timer.start(); // transmission lag |
hudakz | 0:1b9561cd1c36 | 126 | } |
hudakz | 0:1b9561cd1c36 | 127 | } |
hudakz | 0:1b9561cd1c36 | 128 | } |
hudakz | 0:1b9561cd1c36 | 129 | } |