Renard To GECE

renard_to_gece.pde

#define XMAS_PIN 8
#define xmas_color_t uint16_t

#define XMAS_LIGHT_COUNT    (50)

#define XMAS_CHANNEL_MAX          (0xF)
#define XMAS_DEFAULT_INTENSITY     (0xCC)
#define XMAS_COLOR(r,g,b)     ((r)+((g)<<4)+((b)<<8))
#define XMAS_COLOR_WHITE     XMAS_COLOR(XMAS_CHANNEL_MAX,XMAS_CHANNEL_MAX,XMAS_CHANNEL_MAX)
#define XMAS_COLOR_BLACK     XMAS_COLOR(0,0,0)

bool sync;

void xmas_begin(uint8_t pin);
void xmas_one(uint8_t pin);
void xmas_zero(uint8_t pin);
void xmas_end(uint8_t pin);

void xmas_begin(uint8_t pin)
{
  digitalWrite(pin,1);
  delayMicroseconds(7);
  digitalWrite(pin,0);
}

void xmas_one(uint8_t pin)
{
  digitalWrite(pin,0);
  delayMicroseconds(11); //This results in a 20 uS long low
  digitalWrite(pin,1);
  delayMicroseconds(7);
  digitalWrite(pin,0);
}

void xmas_zero(uint8_t pin)
{
  digitalWrite(pin,0);
  delayMicroseconds(2); 
  digitalWrite(pin,1);
  delayMicroseconds(20-3); 
  digitalWrite(pin,0);
}

void xmas_end(uint8_t pin)
{
  digitalWrite(pin,0);
  delayMicroseconds(40); // Can be made shorter
}


void xmas_set_color(uint8_t led,uint8_t intensity,xmas_color_t color, uint8_t pin)
{
  uint8_t i;

  xmas_begin(pin);

  //6-Bit bulb address (MSB first)
  for(i=6;i;i--,(led<<=1))
  {
    if(led&(1<<5))
      xmas_one(pin);
    else
      xmas_zero(pin);
  }

  //8-Bit brightness (MSB first)
  for(i=8;i;i--,(intensity<<=1))
  {
    if(intensity&(1<<7))
      xmas_one(pin);
    else
      xmas_zero(pin);
  }

  //12 bit Color (Blue, Green, Red) (MSB first)
  for(i=12;i;i--,(color<<=1))
  {
    if(color&(1<<11))
      xmas_one(pin);
    else
      xmas_zero(pin);
  }

  xmas_end(pin);
}

void xmas_set_all_one_address(uint8_t pin)
{
  for (int i = 0; i < XMAS_LIGHT_COUNT; ++i)
    xmas_set_color(0,XMAS_DEFAULT_INTENSITY,XMAS_COLOR_BLACK,pin);
}

void setup()
{
  delay(10);
  Serial.begin(57600);
  delay(10);

  pinMode(5, OUTPUT);
  digitalWrite(5, LOW);

  pinMode(XMAS_PIN, OUTPUT);
  digitalWrite(XMAS_PIN, 0);
  xmas_set_all_one_address(XMAS_PIN);

  sync = false;
}

void wait_for_serial()
{
	while ( ! Serial.available() > 0 ) { }
}

int renardReadBytes( uint8_t *bytes, uint8_t bytes_size )
{
  int in_byte = 0;
  int bytes_read;

  for ( bytes_read = 0; bytes_read < bytes_size; )
  {
	wait_for_serial();
    in_byte = Serial.read();

    switch (in_byte)
    {
      case(0x7E): // We saw the sync byte, start over!
		sync = true;
        return bytes_read;

      case(0x7D): // Skip the pad byte
        continue;

      case(0x7F): // Escape character, we need to read one more byte to get our actual data
	    wait_for_serial();
        in_byte = Serial.read();
        switch (in_byte)
          {
            case(0x2F): // renard wants an 0x7D
              in_byte = 0x7D;
            case(0x30): // renard wants an 0x7E
              in_byte = 0x7E;
            case(0x31): // renard wants an 0x7F
              in_byte = 0x7F;
          }
        }

    bytes[bytes_read++] = in_byte;
  }

  return bytes_read;
}

int renardRead( uint8_t *bytes, uint8_t byte_count )
{
  int in_byte = 0;

  while ( ! sync )
  {
	wait_for_serial();
    in_byte = Serial.read();
    if ( in_byte == 0x7E ) // Sync byte signifies start of packet
      sync = true;
  }

  if ( sync )
  {
    sync = false;
	wait_for_serial();
    in_byte = Serial.read();
    if ( in_byte == 0x80 ) // Read from here
    {
      return renardReadBytes(bytes, byte_count);
    }
  }

  return 0;
}

void loop()
{
  uint8_t bytes[4], bytes_read;
  bytes_read = renardRead(&bytes[0], 4);

  if ( bytes_read == 4 )
  {
    // We have now received 4 bytes of data per string, do something with them!
	uint8_t red   = bytes[0];
	uint8_t green = bytes[1];
	uint8_t blue  = bytes[2];
	uint8_t white = bytes[3];


	red = ( red+(white/3) >= (XMAS_CHANNEL_MAX<<4) ? (XMAS_CHANNEL_MAX<<4) : red+(white/3) );
	green = ( green+(white/3) >= (XMAS_CHANNEL_MAX<<4) ? (XMAS_CHANNEL_MAX<<4) : green+(white/3) );
	blue = ( blue+(white/3) >= (XMAS_CHANNEL_MAX<<4) ? (XMAS_CHANNEL_MAX<<4) : blue+(white/3) );

	xmas_set_color(0,XMAS_DEFAULT_INTENSITY,XMAS_COLOR((red>>4),(green>>4),(blue>>4)),XMAS_PIN);
  }
}