Diff: main.cpp

Revision:

13:e741def3e4ff

Parent:

12:e91e44924194

Child:

14:e12ebd1260b1

--- a/main.cpp	Sat Jul 23 08:29:31 2016 +0000
+++ b/main.cpp	Wed Jul 27 09:16:40 2016 +0000
@@ -1,5 +1,5 @@
 /*
- * An example showing how to use the CANnucleo library:
+ * An example of using CAN bus with NUCLEO boards:
  *
  * Two affordable (less than $4 on ebay) STM32F103C8T6 boards (20kB SRAM, 64kB Flash), 
  * compatible with the NUCLEO-F103RB platform (20kB SRAM, 128kB Flash), 
@@ -7,22 +7,21 @@
  * CAN transceivers are not part of NUCLEO boards, therefore must be added by you. 
  * Remember also that CAN bus (even a short one) must be terminated with 120 Ohm resitors at both ends.
  *
- * For more details see the wiki page <https://developer.mbed.org/users/hudakz/code/CANnucleo_Hello/>
+ * For more details see the wiki page [https://developer.mbed.org/users/hudakz/code/CANnucleo_Hello/]
  *
- * NOTE: If you'd like to use the official NUCLEO boards comment out line 25
+ * NOTE: If you'd like to use the official NUCLEO boards comment out line 24
  *
  * The same code is used for both NUCLEO boards, but:
  *      For board #1 compile the example without any change.
- *      For board #2 comment out line 26 before compiling 
+ *      For board #2 comment out line 25 before compiling 
  *
  * Once the binaries have been downloaded to the boards reset board #1.
  *
  */ 
 
 #include "mbed.h"
-#include "CANnucleo.h"
 
-//#define TARGET_STM32F103C8T6  1     // comment out this line when using official NUCLEO boards!                                    
+#define TARGET_STM32F103C8T6  1     // comment out this line when using official NUCLEO boards!                                    
 #define BOARD1                1     // comment out this line when compiling for board #2
 
 #if defined(TARGET_STM32F103C8T6) 
@@ -44,24 +43,11 @@
 #endif
 
 DigitalOut      led(LED_PIN);
-int             ledState;
 Timer           timer;
 CAN             can(PA_11, PA_12);  // CAN Rx pin name, CAN Tx pin name
 CANMessage      rxMsg;
 CANMessage      txMsg;
-int             counter = 0;
-volatile bool   msgAvailable = false;
-
-/**
- * @brief   'CAN receive-complete' interrup handler.
- * @note    Called on arrival of new CAN message.
- *          Keep it as short as possible.
- * @param   
- * @retval  
- */
-void onMsgReceived() {
-    msgAvailable = true;
-}
+char            counter = 0;
 
 /**
  * @brief   Main
@@ -70,8 +56,6 @@
  * @retval
  */
 int main() {
-    can.frequency(1000000);                     // set bit rate to 1Mbps
-    can.attach(&onMsgReceived);                 // attach 'CAN receive-complete' interrupt handler
     
 #if defined(BOARD1)
     led = ON;       // turn LED on
@@ -81,24 +65,19 @@
 #endif
 
     while(1) {
-        if(timer.read() >= 1.0) {               // check for timeout
+        if(timer.read_ms() >= 200) {            // check for timeout
             timer.stop();                       // stop timer
             timer.reset();                      // reset timer
             counter++;                          // increment counter
-            ledState = led.read();              // get led state
-            txMsg.clear();                      // clear Tx message storage
             txMsg.id = TX_ID;                   // set ID
-            txMsg << counter;                   // append first data item
-            txMsg << ledState;                  // append second data item (total data lenght must be <= 8 bytes!)
+            txMsg.data[0] = counter;            // set data
             led = OFF;                          // turn LED off
             if(can.write(txMsg))                // transmit message
                 printf("CAN message sent\r\n"); 
             else
                 printf("Transmission error\r\n");
         }
-        if(msgAvailable) {
-            msgAvailable = false;               // reset flag for next use
-            can.read(rxMsg);                    // read message into Rx message storage
+        if(can.read(rxMsg)) {
             printf("CAN message received:\r\n");
             printf("  ID     = %#x\r\n", rxMsg.id);
             printf("  Type   = %d\r\n", rxMsg.type);
@@ -108,12 +87,11 @@
             for(int i = 0; i < rxMsg.len; i++)
                 printf(" %x", rxMsg.data[i]);
             printf("\r\n");
-            // Filtering performed by software:           
-            if(rxMsg.id == RX_ID) {             // See comments in CAN.cpp for filtering performed by hardware
-                rxMsg >> counter;               // extract first data item
-                rxMsg >> ledState;              // extract second data item
+           
+            if(rxMsg.id == RX_ID) {             
+                counter = rxMsg.data[0];        // set counter
                 printf("counter = %d\r\n", counter);
-                led = ledState;                 // set LED
+                led = !led;                     // set LED
                 timer.start();                  // transmission lag
             }
         }