Diff: ecu_reader.cpp

Revision:

0:78752077cc25

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ecu_reader.cpp	Wed Nov 09 04:59:01 2011 +0000
@@ -0,0 +1,97 @@
+#include "mbed.h"
+#include "ecu_reader.h"
+#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);
+}
+
+//#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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