+/*! \file nrf.c
+ \author Travis Goodspeed
+ \brief NordicRF Register Interface
+*/
+
+//Higher level left to client application.
+
+#include "platform.h"
+#include "command.h"
+
+#include <signal.h>
+#include <io.h>
+#include <iomacros.h>
+
+#include "nrf.h"
+#include "spi.h"
+
+//This could be more accurate.
+//Does it ever need to be?
+#define NRFSPEED 0
+#define NRFDELAY(x)
+//delay(x)
+
+
+//! Set up the pins for NRF mode.
+void nrfsetup(){
+ P5OUT|=SS;
+ P5DIR|=MOSI+SCK+SS;
+ P5DIR&=~MISO;
+
+ //Begin a new transaction.
+ P5OUT&=~SS;
+ P5OUT|=SS;
+}
+
+
+//! Read and write an NRF byte.
+unsigned char nrftrans8(unsigned char byte){
+ register unsigned int bit;
+ //This function came from the NRF Wikipedia article.
+ //Minor alterations.
+
+ for (bit = 0; bit < 8; bit++) {
+ /* write MOSI on trailing edge of previous clock */
+ if (byte & 0x80)
+ SETMOSI;
+ else
+ CLRMOSI;
+ byte <<= 1;
+
+ SETCLK;
+
+ /* read MISO on trailing edge */
+ byte |= READMISO;
+ CLRCLK;
+ }
+
+ return byte;
+}
+
+
+
+
+//! Handles a Nordic RF command.
+void nrfhandle(unsigned char app,
+ unsigned char verb,
+ unsigned long len){
+ unsigned long i;
+
+ //Raise !SS to end transaction, just in case we forgot.
+ P5OUT|=SS;
+ nrfsetup();
+
+ switch(verb){
+ //PEEK and POKE might come later.
+ case READ:
+ case WRITE:
+ P5OUT&=~SS; //Drop !SS to begin transaction.
+ for(i=0;i<len;i++)
+ cmddata[i]=nrftrans8(cmddata[i]);
+ P5OUT|=SS; //Raise !SS to end transaction.
+ txdata(app,verb,len);
+ break;
+
+
+
+ case PEEK://Grab NRF Register
+ txdata(app,verb,0);
+ break;
+
+ case POKE://Poke NRF Register
+
+ txdata(app,verb,0);
+ break;
+
+ case SETUP:
+ nrfsetup();
+ txdata(app,verb,0);
+ break;
+ }
+
+}