File content as of revision 1:4b7c280d433d:

#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
//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;


    //forming the CAN message payload
    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))) {

    }

    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 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;




}
}