Example how we use hardware CAN Acceptance Mask capability on LPC1768. Documentation is not clear !!!!! Polytech PAris SUd Orsay France

Dependencies:   mbed

Revision:
0:01ac4cd13c69
Child:
1:168415f9f4f0
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sun Mar 20 20:41:53 2011 +0000
@@ -0,0 +1,69 @@
+#include "mbed.h"
+#include "CAN.h"
+
+// We use can on mbed pins 29(CAN_TXD) and 30(CAN_RXD).
+CAN can2(p30, p29);
+Serial pc(USBTX, USBRX); // tx, rx
+
+DigitalOut led1(LED1);
+DigitalOut led2(LED2);
+DigitalOut led3(LED3);
+DigitalOut led4(LED4);
+
+void init_AF( void )
+{
+uint32_t address = 4;
+
+//off mode
+   LPC_CANAF->AFMR = 0x00000001;
+// Set explicit standard Frame
+   LPC_CANAF->SFF_sa = address;// word 1
+                          // CAN2         IDENT           FORCE1
+  LPC_CANAF_RAM->mask[1]=(0X001 << 29) | (0X400 << 16)| (1<<27)|
+                          (0X001 << 13)| (0X500 )     | (1<<11);
+// Only Frame ID 0x400 and 0x500 are received in MBED.
+   address+=4;//add 4 bytes (1 long word) to point to none used word.
+// Set group standard Frame
+   LPC_CANAF->SFF_GRP_sa = address;
+// Set explicit extended Frame
+   LPC_CANAF->EFF_sa = address;
+// Set group extended Frame
+   LPC_CANAF->EFF_GRP_sa = address;
+// Set End of Table  
+   LPC_CANAF->ENDofTable = address;
+// All have ENDofTable address means are not used.
+//normal mode
+   LPC_CANAF->AFMR = 0x00000000;
+   return;
+}
+
+// ISR to read frame but don't work beacause no interrupts
+CANMessage can_MsgRx;
+bool recmess;
+
+void lecture(void){
+   can2.read(can_MsgRx);
+   pc.printf("REC %u\n\r",can_MsgRx.id);
+   recmess=1;
+}
+
+// Main program
+int main() {
+    // 500kbit
+    can2.frequency(500000);
+   // Prepare MASK
+    init_AF();
+
+    while (1) {
+       pc.printf("%8x  %8x ",LPC_CAN2->RFS,LPC_CANAF->LUTerr);
+       pc.printf("%8x %8x %8x %8x\n\r", LPC_CANAF->LUTerrAd,LPC_CAN2->ICR,LPC_CAN2->IER,LPC_CAN2->GSR);
+       wait(0.5);
+       if(recmess){
+            led4=!led4;
+            recmess=0;
+       }
+       if(can2.read(can_MsgRx)){
+                 pc.printf("REC %x\n\r",can_MsgRx.id);
+       }
+    }
+}