11 years, 3 months ago.

how will it compatible with LPC1769

1. include "mbed.h"
2. include "ecu_reader.h"
3. include "globals.h"

Use a timer to see if things take too long Timer CANTimer; namespace mbed {

ecu_reader::ecu_reader(int can_speed) { can2.frequency(can_speed); }

1. define TIMEOUT 200 unsigned char ecu_reader::request(unsigned char pid, char *buffer) { char can_msg[8]; float engine_data;

led1 = 1;

can_msg[0] = 0x02; can_msg[1] = 0x01; can_msg[2] = pid; can_msg[3] = 0; can_msg[4] = 0; can_msg[5] = 0; can_msg[6] = 0; can_msg[7] = 0;

if (can2.write(CANMessage(PID_REQUEST, can_msg, 8))) {

}

led1 = 0; CANTimer.reset(); CANTimer.start();

while(CANTimer.read_ms() < TIMEOUT) {

if (can2.read(can_MsgRx)) {

if((can_MsgRx.id == PID_REPLY) && (can_MsgRx.data[2] == pid)) { switch(can_MsgRx.data[2]) { /* Details from http://en.wikipedia.org/wiki/OBD-II_PIDs */ case ENGINE_RPM: ((A*256)+B)/4 [RPM] engine_data = ((can_MsgRx.data[3]*256) + can_MsgRx.data[4])/4; sprintf(buffer,"%d rpm ",(int) engine_data); break;

case ENGINE_COOLANT_TEMP: A-40 [degree C] engine_data = can_MsgRx.data[3] - 40; sprintf(buffer,"%d degC ",(int) engine_data);

break;

case VEHICLE_SPEED: A [km] engine_data = can_MsgRx.data[3]; sprintf(buffer,"%d km ",(int) engine_data);

break;

case MAF_SENSOR: ((256*A)+B) / 100 [g/s] engine_data = ((can_MsgRx.data[3]*256) + can_MsgRx.data[4])/100; sprintf(buffer,"%d g/s",(int) engine_data);

break;

case O2_VOLTAGE: A * 0.005 (B-128) * 100/128 (if B==0xFF, sensor is not used in trim calc) engine_data = can_MsgRx.data[3]*0.005; sprintf(buffer,"%d v ",(int) engine_data);

case THROTTLE: engine_data = (can_MsgRx.data[3]*100)/255; sprintf(buffer,"%d %% ",(int) engine_data);

break; }

return 1;

}

} }

return 0;

} } namespace mbed

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Last updated: 28 Aug 2012

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Sukkin Pang / ecu_reader