Diff: OBDII.cpp

Revision:

1:4b7c280d433d

Parent:

0:5b4bcf184488

--- 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