radio.c

nordic semiconductor

/*= radio.c =====================================================================
 *
 * Written by  Greg Hunter, University of Technology, Sydney, 2007 for sdcc compiler
 * See radio.h for details
 *
 *==============================================================================
*/

#include "regs24e1.h"
#include "radio.h"
#include "delay.h"
#include "spi.h"
#include "uart.h"

// Parameter definitions (see radio,h)

tRadioParm RadioParm;
tComParm ComParm;

// Inital configuration set up for radio:
#define RADIO_PACKET_SIZE 14 //size of receive packet in bytes
const unsigned char RFConfigBuf[15] =
{
  0x08,RADIO_PACKET_SIZE<<3,  //initial data packet size in bits
  0x00,0x00,0x00,0x00,0x00,   //RX channel 2 address
  0x00,0x00,0x00,0x00,0x04,   //RX channel 1 address
  0x83,                       //32 address bits, 16 bit CRC
  0x6E,                       //power set to -5dBm
  0x33                        //RF channel set to #25, RX on
};

//********************************************************
// RadioInit
//  Initialise radio buffer
//********************************************************
void RadioInit(void)
{
  unsigned char i;
  unsigned char *cpt;
  unsigned char *bpt;
//initialise configuration buffer
  cpt = &RFConfigBuf[0];
  bpt = RadioCfgBufPt;
  for (i=0;i<15;i++)
  {
    *bpt = *cpt;
    bpt++;
    cpt++;
  }
}

//********************************************************
// RadioOn
//  Turn on radio
//********************************************************
void RadioOn(void)
{
//turn on radio
  PWR_UP = 1;
//wait 3ms
  Delay100us(30);
//configure spi bus
  SpiRadio();
}

//********************************************************
// RadioCfg
//  Load configuration
//********************************************************
void RadioCfg(void)
{
//configure radio
  CE = 0;
  CS = 1;
  Delay5us();
  SpiWriteBuf(RadioCfgBufPt,RADIO_CFG_BYTES);
  CS = 0;
//switch radio to active mode
  CE = 1;
  Delay5us();
}

//********************************************************
// RadioTXBuf
//  Transmit data in buffer pointed to by bufPt and of length bytes
//  The radio is switched back to receive mode after transmission
//  Note for timing it takes 700us for reciever to be ready after
//   a packet is transmitted
//********************************************************
void RadioTXBuf(unsigned char *bufPt, unsigned char bytes)
{
//switch radio to config mode
  CE = 0;
  Delay100us(3);
//change to transmit mode
  //change buffer to TX mode
    RadioParm.ChnRxTx &= ~0x01;
  //write change ot last byte in radio configuration
    CS = 1;
    SpiReadWrite(RadioParm.ChnRxTx);
    CS = 0;
    Delay5us();
//switch radio to active mode
  CE = 1;
  Delay5us();
//send data buffer to spi starting at top byte address of TXAddress, a 4 byte variable
  SpiWriteBuf(bufPt, bytes);
//switch radio back to config mode
  CE = 0;
//add delay, worked out by trial and error: 300us does not work, 400us does work, 500us used
  Delay100us(5);
//change to receive mode
  //change buffer to RX mode
    RadioParm.ChnRxTx |= 0x01;
  //send channel number and TXRX byte to configuration
    CS = 1;
    SpiReadWrite(RadioParm.ChnRxTx);
    CS = 0;
    Delay5us();
//switch radio to active mode
 CE = 1;
}

//********************************************************
// RadioRXBuf
//  Receive data to buffer bufPt
//  Assumes bufPt points to a byte buffer the same size as the receiver packet size setting in RadioParm.Data1
//  returns 1 if packet received, 0 otherwise
//********************************************************
unsigned char RadioRXBuf(unsigned char *bufPt)
{
  unsigned char r;    //return value
//test if packet received, DR1 = 1
  if(DR1 == 1)
  {
//packet received (0,1)#
  //set returned value to 1
    r = 1;
  //load packet into data buffer
//    CE = 1;
    SpiReadBuf(bufPt,RadioParm.Data1>>3);
  //clear receive buffer
    while(DR1==1)
      SpiReadWrite(0);
//    CE = 0;
  }else
  {
//packet not received #(0,1)
  //set return value to 0
    r = 0;
  }
//return
  return r;
}