main.cpp

00001 /*
00002  * An example showing how to use the mbed CAN API:
00003  *
00004  * Two affordable (about $2 on ebay) STM32F103C8T6 boards (20kB SRAM, 64kB Flash),
00005  * (see [https://developer.mbed.org/users/hudakz/code/STM32F103C8T6_Hello/] for more details)
00006  * are connected to the same CAN bus via transceivers (MCP2551 or TJA1040, or etc.).
00007  * CAN transceivers are not part of NUCLEO boards, therefore must be added by you.
00008  * Remember also that CAN bus (even a short one) must be terminated with 120 Ohm resitors at both ends.
00009  *
00010  * For more details see the wiki page <https://developer.mbed.org/users/hudakz/code/CAN_Hello/>
00011  *
00012  * NOTE: When using an STM32F103C8T6 board uncomment line 22 and import the mbed-STM32F103C8T6 library 
00013  *
00014  * The same code is used for both mbed boards, but:
00015  *      For board #1 compile the example without any change.
00016  *      For board #2 comment out line 21 before compiling
00017  *
00018  * Once the binaries have been downloaded to the boards reset both boards at the same time.
00019  *
00020  */
00021 
00022 #define TARGET_STM32F103C8T6    1       // uncomment this line and import the mbed-STM32F103C8T6 library when using STM32F103C8T6 boards!
00023 
00024 //#define BOARD1                  1       // comment out this line when compiling for board #2
00025 
00026 #if defined(TARGET_STM32F103C8T6)
00027 //#include "stm32f103c8t6.h"
00028 #define LED_PIN PC_13
00029 const int           OFF = 1;
00030 const int           ON = 0;
00031 #else
00032 #define LED_PIN LED1
00033 const int           OFF = 0;
00034 const int           ON = 1;
00035 #endif
00036 #if defined(BOARD1)
00037 const unsigned int  RX_ID = 0x100;
00038 const unsigned int  TX_ID = 0x101;
00039 #else
00040 const unsigned int  RX_ID = 0x101;
00041 const unsigned int  TX_ID = 0x100;
00042 #endif
00043 #include "mbed.h"
00044 #include "CANMsg.h"
00045 
00046 #define CAN_RF0R    (*((volatile unsigned long *)0x4000640C))
00047 #define CAN_RF1R    (*((volatile unsigned long *)0x40006410))
00048 #define CAN_IER     (*((volatile unsigned long *)0x40006414))
00049 
00050 
00051 Serial              pc(PA_9, PA_10);
00052 CAN                 can2(PA_11, PA_12);
00053 CAN                 can(PB_8, PB_9);    // CAN Rx pin name, CAN Tx pin name
00054 CANMsg              rxMsg;
00055 CANMsg              txMsg;
00056 DigitalOut          led(LED_PIN);
00057 Timer               timer;
00058 uint8_t             counter = 0;
00059 AnalogIn            analogIn(A0);
00060 float               voltage;
00061 volatile bool got_message = false;
00062 /**
00063  * @brief   Prints CAN msg to PC's serial terminal
00064  * @note
00065  * @param   CANMessage to print
00066  * @retval
00067  */
00068 void printMsg(CANMessage& msg) {
00069     pc.printf("  ID      = 0x%.3x\r\n", msg.id);
00070     pc.printf("  Type    = %d\r\n", msg.type);
00071     pc.printf("  Format  = %d\r\n", msg.format);
00072     pc.printf("  Length  = %d\r\n", msg.len);
00073     pc.printf("  Data    =");
00074     for(int i = 0; i < msg.len; i++)
00075         pc.printf(" 0x%.2X", msg.data[i]);
00076     pc.printf("\r\n");
00077 }
00078 
00079 void RxIsr(){
00080             CANMsg              temp;
00081             led = ON;
00082             can.read(temp);
00083             got_message = true;
00084             return;
00085                 }
00086 
00087 /**
00088  * @brief   Main
00089  * @note
00090  * @param
00091  * @retval
00092  */
00093 int main(void)
00094 {
00095 #if defined(TARGET_STM32F103C8T6)
00096 //    confSysClock();         //Configure system clock (72MHz HSE clock, 48MHz USB clock)
00097 #endif
00098     pc.baud(9600);          // set Serial speed
00099     can.frequency(5000000); // set bit rate to 1Mbps
00100     can.mode(CAN::Normal);
00101     can.attach(&RxIsr, CAN::RxIrq);
00102 #if defined(BOARD1) 
00103     led = ON;               // turn the LED on
00104     timer.start();          // start timert
00105     pc.printf("CAN_Hello board #1\r\n");
00106 #else
00107     led = OFF;      // turn LED off
00108     pc.printf("CAN_Hello board #2\r\n");
00109 #endif
00110     
00111 while(1) {
00112         pc.printf("%d\n",got_message);
00113         if(timer.read_ms() >= 1000) {    // check for timeout
00114             timer.stop();                // stop timer
00115             timer.reset();               // reset timer
00116             counter++;                   // increment counter
00117             voltage = analogIn * 3.3f;   // read the small drifting voltage from analog input
00118             txMsg.clear();               // clear Tx message storage
00119             txMsg.id = TX_ID;            // set ID
00120             txMsg << counter << voltage; // append data (total data length must not exceed 8 bytes!)
00121             if(can.write(txMsg)) {       // transmit message
00122                 led = OFF;               // turn the LED off
00123                 pc.printf("-------------------------------------\r\n");
00124                 pc.printf("CAN message sent\r\n");
00125                 printMsg(txMsg);
00126                 pc.printf("  counter = %d\r\n", counter);
00127                 pc.printf("  voltage = %e V\r\n", voltage);
00128             }
00129             else
00130                 pc.printf("Transmission error\r\n");
00131         }
00132         
00133         if(got_message){
00134             got_message = false;
00135             can.read(rxMsg);
00136             pc.printf("-------------------------------------\r\n");
00137             pc.printf("CAN message received\r\n");
00138             printMsg(rxMsg);
00139 
00140             // Filtering performed by software:
00141             //if(rxMsg.id == RX_ID) {
00142                 rxMsg >> counter >> voltage;    // extract data from the received CAN message
00143                 pc.printf("  counter = %d\r\n", counter);
00144                 pc.printf("  voltage = %e V\r\n", voltage);
00145                 timer.start();                  // transmission lag
00146 //            }
00147             }
00148 
00149     }
00150 }