new_2019

Dependencies:   mbed CANMsg

Committer:
hudakz
Date:
Fri Mar 17 16:38:46 2017 +0000
Revision:
0:1b9561cd1c36
Child:
1:6f8ffb2c2dd7
Initial release.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
hudakz 0:1b9561cd1c36 1 /*
hudakz 0:1b9561cd1c36 2 * A demo showing how to use CAN bus and the CANMsg library's << (append) and the >> (extract) operators
hudakz 0:1b9561cd1c36 3 *
hudakz 0:1b9561cd1c36 4 * Two affordable (less than $3 on ebay) STM32F103C8T6 boards (20kB SRAM, 64kB Flash),
hudakz 0:1b9561cd1c36 5 * are connected to the same CAN bus via transceivers (MCP2551 or TJA1040, or etc.).
hudakz 0:1b9561cd1c36 6 * CAN transceivers are not part of NUCLEO boards, therefore must be added by you.
hudakz 0:1b9561cd1c36 7 * Remember also that CAN bus (even a short one) must be terminated with 120 Ohm resitors at both ends.
hudakz 0:1b9561cd1c36 8 * In this demo, the mbed board is transmitting two data items to the CAN bus.
hudakz 0:1b9561cd1c36 9 * counter: uint_8 value (one byte).
hudakz 0:1b9561cd1c36 10 * voltage: floating point value (four bytes).
hudakz 0:1b9561cd1c36 11 * So the total length of payload data is five bytes.
hudakz 0:1b9561cd1c36 12 * The "<<" (append) operator is used to add data to the CAN message.
hudakz 0:1b9561cd1c36 13 * If a CAN message is received its ID is checked. If there is match with the awaited ID
hudakz 0:1b9561cd1c36 14 * then data is extracted from the CAN message using the ">>" (extract) operator.
hudakz 0:1b9561cd1c36 15 *
hudakz 0:1b9561cd1c36 16 * The usage of "<<" and ">>" operators is similar to the C++ io-stream ones.
hudakz 0:1b9561cd1c36 17 * Data length of CAN message is automatically updated when using "<<" or ">>" operators.
hudakz 0:1b9561cd1c36 18 *
hudakz 0:1b9561cd1c36 19 * For schematic see the wiki page <https://developer.mbed.org/users/hudakz/code/CAN_Hello/>
hudakz 0:1b9561cd1c36 20 *
hudakz 0:1b9561cd1c36 21 * NOTE: If you'd like to use an STM32F103C8T6 board uncomment line 28
hudakz 0:1b9561cd1c36 22 *
hudakz 0:1b9561cd1c36 23 * The same code is used for both NUCLEO boards, but:
hudakz 0:1b9561cd1c36 24 * For board #1 compile the example without any change.
hudakz 0:1b9561cd1c36 25 * For board #2 comment out line 27 before compilation
hudakz 0:1b9561cd1c36 26 *
hudakz 0:1b9561cd1c36 27 * Once the binaries have been downloaded to the boards reset board #1.
hudakz 0:1b9561cd1c36 28 *
hudakz 0:1b9561cd1c36 29 */
hudakz 0:1b9561cd1c36 30 #define BOARD1 1 // comment out this line when compiling for board #2
hudakz 0:1b9561cd1c36 31 //#define TARGET_STM32F103C8T6 1 // uncomment this line when using STM32F103C8T6 boards!
hudakz 0:1b9561cd1c36 32
hudakz 0:1b9561cd1c36 33 #if defined(TARGET_STM32F103C8T6)
hudakz 0:1b9561cd1c36 34 #include "stm32f103c8t6.h"
hudakz 0:1b9561cd1c36 35 #define LED_PIN PC_13
hudakz 0:1b9561cd1c36 36 const int OFF = 1;
hudakz 0:1b9561cd1c36 37 const int ON = 0;
hudakz 0:1b9561cd1c36 38 #else
hudakz 0:1b9561cd1c36 39 #define LED_PIN LED1
hudakz 0:1b9561cd1c36 40 const int OFF = 0;
hudakz 0:1b9561cd1c36 41 const int ON = 1;
hudakz 0:1b9561cd1c36 42 #endif
hudakz 0:1b9561cd1c36 43 #if defined(BOARD1)
hudakz 0:1b9561cd1c36 44 const unsigned int RX_ID = 0x100;
hudakz 0:1b9561cd1c36 45 const unsigned int TX_ID = 0x101;
hudakz 0:1b9561cd1c36 46 #else
hudakz 0:1b9561cd1c36 47 const unsigned int RX_ID = 0x101;
hudakz 0:1b9561cd1c36 48 const unsigned int TX_ID = 0x100;
hudakz 0:1b9561cd1c36 49 #endif
hudakz 0:1b9561cd1c36 50
hudakz 0:1b9561cd1c36 51 #include "mbed.h"
hudakz 0:1b9561cd1c36 52 #include "CANMsg.h"
hudakz 0:1b9561cd1c36 53
hudakz 0:1b9561cd1c36 54 Serial pc(USBTX, USBRX);
hudakz 0:1b9561cd1c36 55 CAN can(PA_11, PA_12); // CAN Rx pin name, CAN Tx pin name
hudakz 0:1b9561cd1c36 56 CANMsg rxMsg;
hudakz 0:1b9561cd1c36 57 CANMsg txMsg;
hudakz 0:1b9561cd1c36 58 DigitalOut led(LED_PIN);
hudakz 0:1b9561cd1c36 59 Timer timer;
hudakz 0:1b9561cd1c36 60 uint8_t counter = 0;
hudakz 0:1b9561cd1c36 61 AnalogIn analogIn(A0);
hudakz 0:1b9561cd1c36 62 float voltage;
hudakz 0:1b9561cd1c36 63
hudakz 0:1b9561cd1c36 64 /**
hudakz 0:1b9561cd1c36 65 * @brief Prints CAN msg to PC's serial terminal
hudakz 0:1b9561cd1c36 66 * @note}
hudakz 0:1b9561cd1c36 67 * @param CANMess to print
hudakz 0:1b9561cd1c36 68 * @retval none
hudakz 0:1b9561cd1c36 69 */
hudakz 0:1b9561cd1c36 70 void printMsg(CANMsg& msg) {
hudakz 0:1b9561cd1c36 71 pc.printf(" ID = 0x%.3x\r\n", msg.id);
hudakz 0:1b9561cd1c36 72 pc.printf(" Type = %d\r\n", msg.type);
hudakz 0:1b9561cd1c36 73 pc.printf(" Format = %d\r\n", msg.format);
hudakz 0:1b9561cd1c36 74 pc.printf(" Length = %d\r\n", msg.len);
hudakz 0:1b9561cd1c36 75 pc.printf(" Data =");
hudakz 0:1b9561cd1c36 76 for(int i = 0; i < msg.len; i++)
hudakz 0:1b9561cd1c36 77 pc.printf(" 0x%.2X", msg.data[i]);
hudakz 0:1b9561cd1c36 78 pc.printf("\r\n");
hudakz 0:1b9561cd1c36 79 }
hudakz 0:1b9561cd1c36 80
hudakz 0:1b9561cd1c36 81 /**
hudakz 0:1b9561cd1c36 82 * @brief Main
hudakz 0:1b9561cd1c36 83 * @note
hudakz 0:1b9561cd1c36 84 * @param
hudakz 0:1b9561cd1c36 85 * @retval
hudakz 0:1b9561cd1c36 86 */
hudakz 0:1b9561cd1c36 87 int main(void)
hudakz 0:1b9561cd1c36 88 {
hudakz 0:1b9561cd1c36 89 #if defined(TARGET_STM32F103C8T6)
hudakz 0:1b9561cd1c36 90 confSysClock(); //Configure system clock (72MHz HSE clock, 48MHz USB clock)
hudakz 0:1b9561cd1c36 91 #endif
hudakz 0:1b9561cd1c36 92
hudakz 0:1b9561cd1c36 93 pc.baud(9600); // set Serial speed
hudakz 0:1b9561cd1c36 94 can.frequency(1000000); // set bit rate to 1Mbps
hudakz 0:1b9561cd1c36 95
hudakz 0:1b9561cd1c36 96 #if defined(BOARD1)
hudakz 0:1b9561cd1c36 97 led = ON; // turn LED on
hudakz 0:1b9561cd1c36 98 timer.start(); // start timer
hudakz 0:1b9561cd1c36 99 pc.printf("CANnucleo_Hello board #1\r\n");
hudakz 0:1b9561cd1c36 100 #else
hudakz 0:1b9561cd1c36 101 led = OFF; // turn LED off
hudakz 0:1b9561cd1c36 102 pc.printf("CANnucleo_Hello board #2\r\n");
hudakz 0:1b9561cd1c36 103 #endif
hudakz 0:1b9561cd1c36 104
hudakz 0:1b9561cd1c36 105 while(1) {
hudakz 0:1b9561cd1c36 106 if(timer.read_ms() >= 1000) {
hudakz 0:1b9561cd1c36 107
hudakz 0:1b9561cd1c36 108 // check for timeout
hudakz 0:1b9561cd1c36 109 timer.stop(); // stop timer
hudakz 0:1b9561cd1c36 110 timer.reset(); // reset timer
hudakz 0:1b9561cd1c36 111 counter++; // increment counter
hudakz 0:1b9561cd1c36 112 voltage = (analogIn * 3.3f) / 4096.0f; // read the small drifting voltage from analog input
hudakz 0:1b9561cd1c36 113 txMsg.clear(); // clear Tx message storage
hudakz 0:1b9561cd1c36 114 txMsg.id = TX_ID; // set ID
hudakz 0:1b9561cd1c36 115 txMsg << counter << voltage; // append data (total data length must be <= 8 bytes!)
hudakz 0:1b9561cd1c36 116 if(can.write(txMsg)) {
hudakz 0:1b9561cd1c36 117
hudakz 0:1b9561cd1c36 118 // transmit message
hudakz 0:1b9561cd1c36 119 led = OFF; // turn LED off
hudakz 0:1b9561cd1c36 120 pc.printf("-------------------------------------\r\n");
hudakz 0:1b9561cd1c36 121 pc.printf("CAN message sent\r\n");
hudakz 0:1b9561cd1c36 122 printMsg(txMsg);
hudakz 0:1b9561cd1c36 123 pc.printf(" counter = %d\r\n", counter);
hudakz 0:1b9561cd1c36 124 pc.printf(" voltage = %e V\r\n", voltage);
hudakz 0:1b9561cd1c36 125 }
hudakz 0:1b9561cd1c36 126 else
hudakz 0:1b9561cd1c36 127 pc.printf("Transmission error\r\n");
hudakz 0:1b9561cd1c36 128 }
hudakz 0:1b9561cd1c36 129
hudakz 0:1b9561cd1c36 130 if(can.read(rxMsg)) {
hudakz 0:1b9561cd1c36 131 led = ON; // turn LED on
hudakz 0:1b9561cd1c36 132 pc.printf("-------------------------------------\r\n");
hudakz 0:1b9561cd1c36 133 pc.printf("CAN message received\r\n");
hudakz 0:1b9561cd1c36 134 printMsg(rxMsg);
hudakz 0:1b9561cd1c36 135
hudakz 0:1b9561cd1c36 136 // Filtering performed by software:
hudakz 0:1b9561cd1c36 137 if(rxMsg.id == RX_ID) {
hudakz 0:1b9561cd1c36 138 rxMsg >> counter >> voltage; // extract data from the received CAN message
hudakz 0:1b9561cd1c36 139 pc.printf(" counter = %d\r\n", counter);
hudakz 0:1b9561cd1c36 140 pc.printf(" voltage = %e V\r\n", voltage);
hudakz 0:1b9561cd1c36 141 timer.start(); // transmission lag
hudakz 0:1b9561cd1c36 142 }
hudakz 0:1b9561cd1c36 143 }
hudakz 0:1b9561cd1c36 144 }
hudakz 0:1b9561cd1c36 145 }