Arduino nRF RGB colour changer

/*

 This program receive RGB colour codes from nRF radio and analogWrite the colour to the RGB LED strip

 Date : 20/06/2013
 Written by Stanley Seow
 stanleyseow@gmail.com
*/


#include <SPI.h>
#include "nRF24L01.h"
#include "RF24.h"
#include "printf.h"

#define RED_PIN 5
#define GREEN_PIN 3
#define BLUE_PIN 6


RF24 radio(8,9);

// Radio pipe addresses for the 2 nodes to communicate.

const uint64_t pipes[6] = { 0xDEDEDEDEE7ULL, 0xDEDEDEDEE9ULL  };

char receivePayload[31];

int r,g,b = 0;
char red[3], green[3], blue[3];

void setup(void)
{

  pinMode(RED_PIN, OUTPUT);
  pinMode(GREEN_PIN, OUTPUT);
  pinMode(BLUE_PIN, OUTPUT);

  Serial.begin(57600);
  printf_begin();

  radio.begin();

  radio.setDataRate(RF24_250KBPS);
  radio.setPALevel(RF24_PA_MAX);
  radio.setChannel(85);
  radio.enableDynamicPayloads();
  radio.setRetries(15,15);

  radio.setCRCLength(RF24_CRC_16);

  radio.openWritingPipe(pipes[0]);
  radio.openReadingPipe(1,pipes[1]);

  radio.startListening();
  radio.printDetails();

  delay(1000);

}

void loop(void)
{

    uint8_t len = 0;

    // Loop thru the pipes 0 to 5 and check for payloads
    if ( radio.available() ) {
      bool done = false;
      while (!done)
      {
        len = radio.getDynamicPayloadSize();
        done = radio.read( &receivePayload,len );

        receivePayload[len] = 0;
        printf("Got payload: %s len:%i 0x%x\n\r",receivePayload,len);

        // Strip the red, green & blue from the 6 chars
        HEXtoRGB();

        printf("%s %s %s\n\r",red,green,blue);
        printf("RGB:%i %i %i\n\r",r,g,b);

        analogWrite(RED_PIN,r);
        analogWrite(GREEN_PIN,g);
        analogWrite(BLUE_PIN,b);

        radio.startListening();

      }
    }

   r,g,b = 0;
}

void HEXtoRGB(void) {
/* parse the string into three pieces of two */

    red[0] = toupper(receivePayload[1]);
    red[1] = toupper(receivePayload[2]);
    green[0] = toupper(receivePayload[3]);
    green[1] = toupper(receivePayload[4]);
    blue[0] = toupper(receivePayload[5]);
    blue[1] = toupper(receivePayload[6]);

/* RED ********************************************/
    switch (red[0]) {
        case '0' : { r = 0; break; }
        case '1' : { r = 16; break; }
        case '2' : { r = 32; break; }
        case '3' : { r = 48; break; }
        case '4' : { r = 64; break; }
        case '5' : { r = 80; break; }
        case '6' : { r = 96; break; }
        case '7' : { r = 112; break; }
        case '8' : { r = 128; break; }
        case '9' : { r = 144; break; }
        case 'A' : { r = 160; break; }
        case 'B' : { r = 176; break; }
        case 'C' : { r = 192; break; }
        case 'D' : { r = 208; break; }
        case 'E' : { r = 224; break; }
        case 'F' : { r = 240; break; }
    }

    switch (red[1]) {
        case '0' : { r = r + 0; break; }
        case '1' : { r = r + 1; break; }
        case '2' : { r = r + 2; break; }
        case '3' : { r = r + 3; break; }
        case '4' : { r = r + 4; break; }
        case '5' : { r = r + 5; break; }
        case '6' : { r = r + 6; break; }
        case '7' : { r = r + 7; break; }
        case '8' : { r = r + 8; break; }
        case '9' : { r = r + 9; break; }
        case 'A' : { r = r + 10; break; }
        case 'B' : { r = r + 11; break; }
        case 'C' : { r = r + 12; break; }
        case 'D' : { r = r + 13; break; }
        case 'E' : { r = r + 14; break; }
        case 'F' : { r = r + 15; break; }
    }

/* GREEN ********************************************/
    switch (green[0]) {
        case '0' : { g = 0; break; }
        case '1' : { g = 16; break; }
        case '2' : { g = 32; break; }
        case '3' : { g = 48; break; }
        case '4' : { g = 64; break; }
        case '5' : { g = 80; break; }
        case '6' : { g = 96; break; }
        case '7' : { g = 112; break; }
        case '8' : { g = 128; break; }
        case '9' : { g = 144; break; }
        case 'A' : { g = 160; break; }
        case 'B' : { g = 176; break; }
        case 'C' : { g = 192; break; }
        case 'D' : { g = 208; break; }
        case 'E' : { g = 224; break; }
        case 'F' : { g = 240; break; }
    }
    switch (green[1]) {
        case '0' : { g = g + 0; break; }
        case '1' : { g = g + 1; break; }
        case '2' : { g = g + 2; break; }
        case '3' : { g = g + 3; break; }
        case '4' : { g = g + 4; break; }
        case '5' : { g = g + 5; break; }
        case '6' : { g = g + 6; break; }
        case '7' : { g = g + 7; break; }
        case '8' : { g = g + 8; break; }
        case '9' : { g = g + 9; break; }
        case 'A' : { g = g + 10; break; }
        case 'B' : { g = g + 11; break; }
        case 'C' : { g = g + 12; break; }
        case 'D' : { g = g + 13; break; }
        case 'E' : { g = g + 14; break; }
        case 'F' : { g = g + 15; break; }
    }

/* BLUE ********************************************/
    switch (blue[0]) {
        case '0' : { b = 0; break; }
        case '1' : { b = 16; break; }
        case '2' : { b = 32; break; }
        case '3' : { b = 48; break; }
        case '4' : { b = 64; break; }
        case '5' : { b = 80; break; }
        case '6' : { b = 96; break; }
        case '7' : { b = 112; break; }
        case '8' : { b = 128; break; }
        case '9' : { b = 144; break; }
        case 'A' : { b = 160; break; }
        case 'B' : { b = 176; break; }
        case 'C' : { b = 192; break; }
        case 'D' : { b = 208; break; }
        case 'E' : { b = 224; break; }
        case 'F' : { b = 240; break; }
    }

    switch (blue[1]) {
        case '0' : { b = b + 0; break; }
        case '1' : { b = b + 1; break; }
        case '2' : { b = b + 2; break; }
        case '3' : { b = b + 3; break; }
        case '4' : { b = b + 4; break; }
        case '5' : { b = b + 5; break; }
        case '6' : { b = b + 6; break; }
        case '7' : { b = b + 7; break; }
        case '8' : { b = b + 8; break; }
        case '9' : { b = b + 9; break; }
        case 'A' : { b = b + 10; break; }
        case 'B' : { b = b + 11; break; }
        case 'C' : { b = b + 12; break; }
        case 'D' : { b = b + 13; break; }
        case 'E' : { b = b + 14; break; }
        case 'F' : { b = b + 15; break; }
    }
} /* end of Hex to RGB */