File content as of revision 1:42b124ed1f57:

#include "RF12B.h"

RF12B::RF12B(PinName SDI,
             PinName SDO,
             PinName SCK,
             PinName NCS,
             PinName NIRQ):spi(SDI, SDO, SCK),
        NCS(NCS), NIRQ(NIRQ) {
    this->initialized = false;
    this->trans = false;

    this->spi.format(16,0);
    this->spi.frequency(2000000);
    this->NCS = 1;
}

/* Initialises the RF12B module as transmitter
    or receiver. This should be called after the
    RF module has fully started up (give it a
    few hundred ms) */
void RF12B::init(bool _trans) {
    trans = _trans;

    writeCmd(0x80E7); //EL,EF,868band,12.0pF
    if (trans) {
        writeCmd(0x8239); //!er,!ebb,ET,ES,EX,!eb,!ew,DC
    } else {
        writeCmd(0x8299); //er,!ebb,ET,ES,EX,!eb,!ew,DC
    }
    writeCmd(0xA640); //frequency select
    writeCmd(0xC647); //4.8kbps
    writeCmd(0x94A0); //VDI,FAST,134kHz,0dBm,-103dBm
    writeCmd(0xC2AC); //AL,!ml,DIG,DQD4
    writeCmd(0xCA81); //FIFO8,SYNC,!ff,DR
    writeCmd(0xCED4); //SYNC=2DD4
    writeCmd(0xC483); //@PWR,NO RSTRIC,!st,!fi,OE,EN
    writeCmd(0x9850); //!mp,90kHz,MAX OUT
    writeCmd(0xCC17); //OB1, COB0, LPX, Iddy, CDDITCBW0
    writeCmd(0xE000); //NOT USED
    writeCmd(0xC800); //NOT USED
    writeCmd(0xC040); //1.66MHz,2.2V

    initialized = true;
}

/* Reads a byte of data from the RF module's buffer
    This is a blocking call */
unsigned char RF12B::read() {
    if (!initialized) {
        init(false); //Receiver
        trans = false;
        initialized = true;
    }
    if(trans) {
        return 0;
    }
    
    unsigned int data;
    while (1) {
        data = writeCmd(0x0000);
        if ( (data&0x8000) ) {
            data = writeCmd(0xB000);
            return (data&0x00FF);
        }
    }
}

/* Sends a byte of data to the RF module for transmission */
void RF12B::write(unsigned char *data) {
        writeCmd(0x0000);
        send(0xAA); // PREAMBLE
        send(0xAA);
        send(0xAA);
        send(0x2D); // SYNC
        send(0xD4);
        for (int i=0; i<16; i++) {
            send(data[i]);
        }
        send(0xAA); // DUMMY BYTES
        send(0xAA);
        send(0xAA);
}

void RF12B::send(unsigned char data) {
    if (!initialized) {
        init(true); //Transmitter
        trans = true;
        initialized = true;
    }
    if (!trans) {
        return; // Must be in transmitter mode!
    }

    while (NIRQ);
    writeCmd(0xB800 + data);
}

/* Flushes all data from the RF module's buffer */
void RF12B::flush() {
    if (!trans) {
        writeCmd(0xCA81);
        writeCmd(0xCA83);
    }
};

unsigned int RF12B::writeCmd(unsigned int cmd) {
    unsigned int recv;
    NCS = 0;
    recv = spi.write(cmd);
    NCS = 1;
    return recv;
}