can.cpp

00001 #include "mbed.h"
00002 #include "can.h"
00003 
00004 
00005 
00006 //---------------------------------------
00007 // Hardware recources
00008 //---------------------------------------
00009 CAN can1(p30, p29);
00010 
00011 
00012 
00013 //---------------------------------------
00014 // Prototypes
00015 //---------------------------------------
00016 static void CAN_rxCallback( void );
00017 
00018 
00019 
00020 //---------------------------------------
00021 // Internal variables
00022 //---------------------------------------
00023 static CANMessage CAN_rxMessage;
00024 static bool CAN_newFrame = false;
00025 
00026 
00027 
00028 //---------------------------------------
00029 // External variables
00030 //---------------------------------------
00031 
00032 
00033 
00034 //---------------------------------------
00035 // Global Functions
00036 //---------------------------------------
00037 void CAN_init( void )
00038 {   
00039     CAN_newFrame = false;
00040     can1.reset();
00041     can1.frequency( CAN_FREQUENCY );
00042     can1.attach( &CAN_rxCallback );
00043 }
00044 
00045 
00046 // Return:
00047 // 0 --> no new frame
00048 // 1 --> new frame was received
00049 int CAN_get( int *ptrID, char *ptrLen, char *ptrData )
00050 {
00051     int i;
00052     
00053     // No new frame
00054     if( CAN_newFrame == false )
00055     {
00056         *ptrID = 0;
00057         *ptrLen = 0;
00058         return 0;
00059     }
00060     
00061     // New frame was received
00062     *ptrID = CAN_rxMessage.id;
00063     *ptrLen = CAN_rxMessage.len; 
00064     for( i = 0; i < CAN_rxMessage.len; i++)
00065     {
00066         *ptrData = CAN_rxMessage.data[i];
00067         ptrData++;
00068     }
00069     
00070     CAN_newFrame = false;
00071     
00072     return 1;
00073 }
00074 
00075 
00076 // Return:
00077 // 0: ID, Len outside limit or CAN hardware problems
00078 // 1: Data have been send
00079 int CAN_send( int ID, char Len, char *ptrData )
00080 {   
00081     // Check limits
00082     if( Len > 8 )
00083     {
00084         return 0;
00085     }
00086     
00087     if( (ID < 0) || (ID > 0x7FF) )
00088     {
00089         return 0;
00090     } 
00091 
00092 
00093     if( can1.write( CANMessage(ID, ptrData, Len) ) )
00094     {
00095         return 1;
00096     }
00097    
00098     // Error sending data --> reset init CAN
00099     CAN_init();
00100     return 0;
00101 }
00102 
00103 
00104 //---------------------------------------
00105 // Internal Functions
00106 //---------------------------------------
00107 
00108 static void CAN_rxCallback( void )
00109 {
00110     can1.read(CAN_rxMessage);
00111     CAN_newFrame = true;
00112 }
00113