File content as of revision 0:9c6b9280c0e1:

#ifndef __PN532_INTERFACE_H__
#define __PN532_INTERFACE_H__

#define PN532_PREAMBLE                      (0x00)
#define PN532_STARTCODE1                    (0x00)
#define PN532_STARTCODE2                    (0xFF)
#define PN532_POSTAMBLE                     (0x00)

#define PN532_HOSTTOPN532                   (0xD4)
#define PN532_PN532TOHOST                   (0xD5)

#define PN532_ACK_WAIT_TIME                 (10)  // ms, timeout of waiting for ACK

#define PN532_INVALID_ACK             (-1)
#define PN532_TIMEOUT                 (-2)
#define PN532_INVALID_FRAME           (-3)
#define PN532_NO_SPACE                (-4)

#define REVERSE_BITS_ORDER(b)         b = (b & 0xF0) >> 4 | (b & 0x0F) << 4; \
                                      b = (b & 0xCC) >> 2 | (b & 0x33) << 2; \
                                      b = (b & 0xAA) >> 1 | (b & 0x55) << 1

class PN532Interface {
public:
    virtual void begin() = 0;
    virtual void wakeup() = 0;
    
    /**
    * @brief    write a command and check ack
    * @param    buf     command to write, not contain prefix and suffix
    * @param    len     lenght of command
    * @return   0       success
    *           not 0   failed
    */
    virtual int8_t writeCommand(const uint8_t buf[], uint8_t len) = 0;
    
    /**
    * @brief    read the response of a command, strip prefix and suffix
    * @param    buf     to contain the response data
    * @param    len     lenght to read
    * @param    timeout max time to wait, 0 means no timeout
    * @return   >=0     length of response without prefix and suffix
    *           <0      failed to read response
    */
    virtual int16_t readResponse(uint8_t buf[], uint8_t len, uint16_t timeout = 1000) = 0; 
};

#endif