generic_CAN_driver.h

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/***********************************************************************/
#ifndef GENERIC_CAN_DRIVER_H_
#define GENERIC_CAN_DRIVER_H_
 
#include "stdint.h"
 
class CANpacket
{
public:
  CANpacket( uint16_t _id=0, uint16_t _dlc=0, uint64_t _data=0)
  : id(_id),
    dlc(_dlc),
    data_l(_data)
  {}
  bool operator ==(const CANpacket&right)
    {
      return    (id == right.id) &&
        (dlc = right.dlc) &&
        (data_l == right.data_l);
    }
  uint16_t id;  
  uint16_t dlc; 
  union
  {
        uint8_t  data_b[8];     
        int8_t   data_sb[8];    
        uint16_t data_h[4];     
        int16_t  data_sh[4];    
        uint32_t data_w[2];     
        int32_t  data_sw[2];    
        float    data_f[2];     
        uint64_t data_l;        
  };
} ;
 
#pragma pack(push, 2)
 
class CAN_gateway_packet
{
public:
  CAN_gateway_packet( const CANpacket &p)
  : ID_checked(p.id),
    DLC_checksum(p.dlc),
    data(p.data_l)
  {
    uint16_t checksum = ~(p.id % 31);
    ID_checked |= checksum << 11;
 
    checksum = (uint16_t) ~(p.data_l % 4095);
    DLC_checksum |= checksum << 4;
  }
 
  bool to_CANpacket( CANpacket &p)
  {
    uint16_t checksum = ~((ID_checked & 0x7ff) % 31) & 0x1f;
    if( ID_checked >> 11 != checksum)
      return false;
 
    checksum = ~(data % 4095) & 0xfff;
    if( DLC_checksum >> 4 != checksum)
      return false;
 
    p.id     = ID_checked & 0x7ff;
    p.dlc    = DLC_checksum & 0x0f;
    p.data_l = data;
 
    return true;
  }
 
public:
  uint16_t ID_checked;
  uint16_t DLC_checksum;
  uint64_t data; //
};
 
#pragma pack(pop)
 
bool CAN_send( const CANpacket &p, unsigned dummy);
 
#endif /* GENERIC_CAN_DRIVER_H_ */