OBDII library, based on SK Pang\\\'s ecu reader. more details to be added shortly.
Diff: OBDII.cpp
- Revision:
- 1:4b7c280d433d
- Parent:
- 0:5b4bcf184488
diff -r 5b4bcf184488 -r 4b7c280d433d OBDII.cpp --- a/OBDII.cpp Mon May 02 02:46:26 2011 +0000 +++ b/OBDII.cpp Mon May 02 04:34:18 2011 +0000 @@ -4,94 +4,88 @@ // Use a timer to see if things take too long -Timer CANTimer; -namespace mbed { - - -OBDII::OBDII(int can_speed) -{ +Timer CANTimer; +namespace mbed { +OBDII::OBDII(int can_speed) { can2.frequency(can_speed); } #define TIMEOUT 200 -unsigned char OBDII::request(unsigned char pid, char *buffer) -{ +//function to request and OBD PID which will be placed in a buffer +unsigned char OBDII::request(unsigned char pid, char *buffer) { char can_msg[8]; float engine_data; - - led1 = 1; - - can_msg[0] = 0x02; + + + //forming the CAN message payload + can_msg[0] = 0x02; can_msg[1] = 0x01; - can_msg[2] = pid; + can_msg[2] = pid; can_msg[3] = 0; - can_msg[4] = 0; + can_msg[4] = 0; can_msg[5] = 0; - can_msg[6] = 0; + can_msg[6] = 0; can_msg[7] = 0; - if (can2.write(CANMessage(PID_REQUEST, can_msg, 8))) { - + 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",(int) engine_data); - break; - - case ENGINE_COOLANT_TEMP: // A-40 [degree C] - engine_data = can_MsgRx.data[3] - 40; - sprintf(buffer,"%d",(int) engine_data); - - break; - - case VEHICLE_SPEED: // A [km] - engine_data = can_MsgRx.data[3]; - sprintf(buffer,"%d",(int) engine_data); - - break; + + 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]) { + case ENGINE_RPM: // ((A*256)+B)/4 [RPM] + engine_data = ((can_MsgRx.data[3]*256) + can_MsgRx.data[4])/4; + sprintf(buffer,"%d",(int) engine_data); + break; + + case ENGINE_COOLANT_TEMP: // A-40 [degree C] + engine_data = can_MsgRx.data[3] - 40; + sprintf(buffer,"%d",(int) engine_data); + + break; + + case VEHICLE_SPEED: // A [km] + engine_data = can_MsgRx.data[3]; + sprintf(buffer,"%d",(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",(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",(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",(int) engine_data); + + case THROTTLE: // + engine_data = (can_MsgRx.data[3]*100)/255; + sprintf(buffer,"%d",(int) engine_data); - 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",(int) engine_data); - - case THROTTLE: // - engine_data = (can_MsgRx.data[3]*100)/255; - sprintf(buffer,"%d",(int) engine_data); - - - break; - } - + + break; + } + return 1; - - } + + } - } - } + } + } - return 0; - + return 0; + } -} // namespace mbed \ No newline at end of file +} \ No newline at end of file