CANMsg.h

Go to the documentation of this file.

#ifndef CANMSG_H
#define CANMSG_H
 
/* CAN message container.
 * Provides "<<" (append) and ">>" (extract) operators to simplyfy
 * adding/getting data items to/from a CAN message.
 * Usage is similar to the C++ io-stream operators.
 * Data length of CAN message is automatically updated when using "<<" or ">>" operators.
 *
 * See Wiki page <https://developer.mbed.org/users/hudakz/code/CAN_Hello/> for demo.
 */
 
#include "CAN.h"
 
class CANMsg : public mbed::CANMessage
{
public:
    CANMsg() :
        CANMessage(){ }
 
    CANMsg(int _id, const char *_data, char _len = 8, CANType _type = CANData, CANFormat _format = CANStandard) :
        CANMessage(_id, _data, _len, _type, _format){ }
 
    CANMsg(int _id, CANFormat _format = CANStandard) :
        CANMessage(_id, _format){ }
 
    void clear(void) {
        len    = 0;
        type   = CANData;
        format = CANStandard;
        id     = 0;
        memset(data, 0, 8);
    };
 
    template<class T>
    CANMsg &operator<<(const T val) {
        MBED_ASSERT(len + sizeof(T) <= 8);
        memcpy(&data[len], &val, sizeof(T));
        len += sizeof(T);
        return *this;
    }
 
    template<class T>
    CANMsg &operator>>(T& val) {
        //printf("Size:%d\tmax length:%d\n", sizeof(T), len);
        MBED_ASSERT(sizeof(T) <= len);
        if (sizeof(T) > len) {
            memcpy(&val, data, len);
            len = 0;
        }
        else {
            memcpy(&val, data, sizeof(T));
            len -= sizeof(T);
        }
        memcpy(data, data + sizeof(T), len);
        return *this;
    }
};
 
#endif // CANMSG_H