OBDII library, based on SK Pang\\\'s ecu reader. more details to be added shortly.
OBDII.cpp
- Committer:
- AliBros
- Date:
- 2011-05-02
- Revision:
- 0:5b4bcf184488
- Child:
- 1:4b7c280d433d
File content as of revision 0:5b4bcf184488:
#include "mbed.h" #include "OBDII.h" #include "globals.h" // Use a timer to see if things take too long 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) { 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",(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 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; } return 1; } } } return 0; } } // namespace mbed