File content as of revision 3:19d3601a7744:

#ifndef A7105_FLYSKY_RX_H
#define A7105_FLYSKY_RX_H

#define NO_ERROR        0
#define TIME_OUT_ERROR  1
#define VALIDITY_ERROR  2
#define TX_ID_ERROR     3

//flysky protocol id  = 0x2AC57554
static const unsigned char flysky_id[4] = { 0x54, 0x75, 0xC5, 0x2A }; //low byte first

//default tx id
static const unsigned char default_tx_id[4] = { 0x06, 0x00, 0x00, 0x30 }; //low byte first (small quadcopter)
//static const unsigned char default_tx_id[4] = { 0xB2, 0xA1, 0x00, 0x00 }; //low byte first (TH9X module)

//A7105 register values (0xFF = don't modify register value)
static const unsigned char A7105_regs_val[] = {
    0xFF, 0x42, 0x00, 0x14, 0x00, 0xFF, 0xFF ,0x00, 0x00, 0x00, 0x00, 0x19, 0x01, 0x05, 0x00, 0x50, //GIO1 Pin Control Register @0x0B = 0x19 - 4 wire dialog spi, miso on pin GIO1
    0x9e, 0x4b, 0x00, 0x02, 0x16, 0x2b, 0x12, 0x00, 0x62, 0x80, 0x80, 0x00, 0x0a, 0x32, 0xc3, 0x0f,
    0x13, 0xc3, 0x00, 0xFF, 0x00, 0x00, 0x3b, 0x00, 0x17, 0x47, 0x80, 0x03, 0x01, 0x45, 0x18, 0x00,
    0x01, 0x0f, 0xFF,
};

//A7105 TX channel number table (for RX substract 1)
static const unsigned char A7105_tx_channels[16][16] = {
  {0x0a, 0x5a, 0x14, 0x64, 0x1e, 0x6e, 0x28, 0x78, 0x32, 0x82, 0x3c, 0x8c, 0x46, 0x96, 0x50, 0xa0},
  {0xa0, 0x50, 0x96, 0x46, 0x8c, 0x3c, 0x82, 0x32, 0x78, 0x28, 0x6e, 0x1e, 0x64, 0x14, 0x5a, 0x0a},
  {0x0a, 0x5a, 0x50, 0xa0, 0x14, 0x64, 0x46, 0x96, 0x1e, 0x6e, 0x3c, 0x8c, 0x28, 0x78, 0x32, 0x82},
  {0x82, 0x32, 0x78, 0x28, 0x8c, 0x3c, 0x6e, 0x1e, 0x96, 0x46, 0x64, 0x14, 0xa0, 0x50, 0x5a, 0x0a},
  {0x28, 0x78, 0x0a, 0x5a, 0x50, 0xa0, 0x14, 0x64, 0x1e, 0x6e, 0x3c, 0x8c, 0x32, 0x82, 0x46, 0x96},
  {0x96, 0x46, 0x82, 0x32, 0x8c, 0x3c, 0x6e, 0x1e, 0x64, 0x14, 0xa0, 0x50, 0x5a, 0x0a, 0x78, 0x28},
  {0x50, 0xa0, 0x28, 0x78, 0x0a, 0x5a, 0x1e, 0x6e, 0x3c, 0x8c, 0x32, 0x82, 0x46, 0x96, 0x14, 0x64},
  {0x64, 0x14, 0x96, 0x46, 0x82, 0x32, 0x8c, 0x3c, 0x6e, 0x1e, 0x5a, 0x0a, 0x78, 0x28, 0xa0, 0x50},
  {0x50, 0xa0, 0x46, 0x96, 0x3c, 0x8c, 0x28, 0x78, 0x0a, 0x5a, 0x32, 0x82, 0x1e, 0x6e, 0x14, 0x64},
  {0x64, 0x14, 0x6e, 0x1e, 0x82, 0x32, 0x5a, 0x0a, 0x78, 0x28, 0x8c, 0x3c, 0x96, 0x46, 0xa0, 0x50},
  {0x46, 0x96, 0x3c, 0x8c, 0x50, 0xa0, 0x28, 0x78, 0x0a, 0x5a, 0x1e, 0x6e, 0x32, 0x82, 0x14, 0x64},
  {0x64, 0x14, 0x82, 0x32, 0x6e, 0x1e, 0x5a, 0x0a, 0x78, 0x28, 0xa0, 0x50, 0x8c, 0x3c, 0x96, 0x46},
  {0x46, 0x96, 0x0a, 0x5a, 0x3c, 0x8c, 0x14, 0x64, 0x50, 0xa0, 0x28, 0x78, 0x1e, 0x6e, 0x32, 0x82},
  {0x82, 0x32, 0x6e, 0x1e, 0x78, 0x28, 0xa0, 0x50, 0x64, 0x14, 0x8c, 0x3c, 0x5a, 0x0a, 0x96, 0x46},
  {0x46, 0x96, 0x0a, 0x5a, 0x50, 0xa0, 0x3c, 0x8c, 0x28, 0x78, 0x1e, 0x6e, 0x32, 0x82, 0x14, 0x64},
  {0x64, 0x14, 0x82, 0x32, 0x6e, 0x1e, 0x78, 0x28, 0x8c, 0x3c, 0xa0, 0x50, 0x5a, 0x0a, 0x96, 0x46},
};

class A7105_flysky_RX
{
    public:
        //constructor, uses SPI, DigitalIn, DigitalOut class
        A7105_flysky_RX(PinName SDIO, PinName GIO1, PinName SCK, PinName CS, PinName GIO2, PinName LED);
        //var
        unsigned short int servoPulseDur[8];    // servo pulse duration (1000->2000), 8x2 bytes
        unsigned char txId[4];                  // expected tx id, 4x1bytes, low byte first    
        unsigned char packetTxId[4];            //tx id in current packet
        //function
        bool init();        //init A7105 chip
        bool bind();        //bind TX and update txId with TX id if succeed, or default txid if failed
        unsigned char waitPacket();  //wait next packet (1.46ms) or timeOut (1.5ms)
      
    private:
        //A7105 dialog
        SPI _spi;               //spi(mosi, miso, sck)
        DigitalOut _cs;         //CS A7105
        DigitalIn _waitRx;      //Wait Rx A7105
        DigitalOut _statusLed;  //status led: FLASH = bind process, ON = rx ok, OFF = no rx      
        //var
        Timer timer;            //"wait packet" timeout timer 1.5ms
        unsigned short int packetServoPulseDur[8];  //servo pulse duration in current packet (1000->2000)
        unsigned char channelCnt;                   //A7105 channel counter (0->15)
        unsigned char channelOffset;                //channel offset
        //function
        void writeCmd(unsigned char cmd);
        void writeRegVal(unsigned char regAddr, unsigned char regVal);
        unsigned char readReg(unsigned char regAddr);
        void readPacket(void);
};

#endif