Ashley Mills / CANInterface

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CANInterface.cpp@0:1ce2190bc4d2, 2014-04-30 (annotated)

Committer:
ashleymills
Date:
Wed Apr 30 13:51:22 2014 +0000
Revision:
0:1ce2190bc4d2
Child:
1:abf508583871
Simple can interface. Based on work by SKPang, but heavily cleaned up and abstracted.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ashleymills 0:1ce2190bc4d2 1 #include "CANInterface.h"
ashleymills 0:1ce2190bc4d2 2
ashleymills 0:1ce2190bc4d2 3 CANInterface::CANInterface(PinName rd, PinName td) {
ashleymills 0:1ce2190bc4d2 4 _can = new CAN(rd,td);
ashleymills 0:1ce2190bc4d2 5 _can->frequency(CANInterface::CAN_SPEED_500);
ashleymills 0:1ce2190bc4d2 6 _timer = new Timer();
ashleymills 0:1ce2190bc4d2 7 _timeout = 200;
ashleymills 0:1ce2190bc4d2 8 }
ashleymills 0:1ce2190bc4d2 9
ashleymills 0:1ce2190bc4d2 10 int CANInterface::makeRequest(uint8_t pid, uint8_t *outBuf, int *outLen) {
ashleymills 0:1ce2190bc4d2 11 char canMsg[8] = {0x02,0x01,pid,0x00,0x00,0x00,0x00,0x00};
ashleymills 0:1ce2190bc4d2 12 int readOK = 0;
ashleymills 0:1ce2190bc4d2 13
ashleymills 0:1ce2190bc4d2 14 // write request
ashleymills 0:1ce2190bc4d2 15 CANMessage request(CAN_PID_REQUEST,canMsg,8);
ashleymills 0:1ce2190bc4d2 16 if(_can->write(request)==0) {
ashleymills 0:1ce2190bc4d2 17 return 1;
ashleymills 0:1ce2190bc4d2 18 }
ashleymills 0:1ce2190bc4d2 19
ashleymills 0:1ce2190bc4d2 20 // get response
ashleymills 0:1ce2190bc4d2 21 CANMessage response;
ashleymills 0:1ce2190bc4d2 22
ashleymills 0:1ce2190bc4d2 23 // start request timer
ashleymills 0:1ce2190bc4d2 24 _timer->reset();
ashleymills 0:1ce2190bc4d2 25 _timer->start();
ashleymills 0:1ce2190bc4d2 26
ashleymills 0:1ce2190bc4d2 27 // wait for response
ashleymills 0:1ce2190bc4d2 28 while(_timer->read_ms() < _timeout) {
ashleymills 0:1ce2190bc4d2 29
ashleymills 0:1ce2190bc4d2 30 // try and read response
ashleymills 0:1ce2190bc4d2 31 if(_can->read(response)) {
ashleymills 0:1ce2190bc4d2 32 readOK = 1;
ashleymills 0:1ce2190bc4d2 33 _timer->stop();
ashleymills 0:1ce2190bc4d2 34 if((response.id == CAN_PID_REPLY) && (response.data[2] == pid)) {
ashleymills 0:1ce2190bc4d2 35 memcpy(outBuf,response.data,response.len-2);
ashleymills 0:1ce2190bc4d2 36 outBuf[0] = response.data[3];
ashleymills 0:1ce2190bc4d2 37 outBuf[1] = response.data[4];
ashleymills 0:1ce2190bc4d2 38 *outLen = response.len-2;
ashleymills 0:1ce2190bc4d2 39 break;
ashleymills 0:1ce2190bc4d2 40 }
ashleymills 0:1ce2190bc4d2 41 }
ashleymills 0:1ce2190bc4d2 42 }
ashleymills 0:1ce2190bc4d2 43 return readOK;
ashleymills 0:1ce2190bc4d2 44 }