#include "pins_arduino.h"

#include "WProgram.h"
void setDmxChannel(byte channelID, byte value);
void shiftDmxOut(int pin, int theByte);
void processDmx();
void setup();
void loop();
int sig = 8; // signal para mochila
//int sig = 5; // signal para placa integrada

int value = 0;
int value1 = 0;
int value2 = 0;
int value3 = 0;
int i=0;
int e=0;
byte checksum;
byte id=0;

int valueadd = 3;

byte buffer[10];
byte color[256];

byte dmxChannel[64];

void setDmxChannel(byte channelID, byte value) {
	if (channelID < 64)
		dmxChannel[channelID] = value;
}

/* Sends a DMX byte out on a pin.  Assumes a 16 MHz clock.
 * Disables interrupts, which will disrupt the millis() function if used
 * too frequently. */
void shiftDmxOut(int pin, int theByte)
{
  int port_to_output[] = {
    NOT_A_PORT,
    NOT_A_PORT,
    _SFR_IO_ADDR(PORTB),
    _SFR_IO_ADDR(PORTC),
    _SFR_IO_ADDR(PORTD)
    };

    int portNumber = port_to_output[digitalPinToPort(pin)];
  int pinMask = digitalPinToBitMask(pin);

  // the first thing we do is to write te pin to high
  // it will be the mark between bytes. It may be also
  // high from before
  _SFR_BYTE(_SFR_IO8(portNumber)) |= pinMask;
  delayMicroseconds(10);

  // disable interrupts, otherwise the timer 0 overflow interrupt that
  // tracks milliseconds will make us delay longer than we want.
  cli();

  // DMX starts with a start-bit that must always be zero
  _SFR_BYTE(_SFR_IO8(portNumber)) &= ~pinMask;

  // we need a delay of 4us (then one bit is transfered)
  // this seems more stable then using delayMicroseconds
  asm("nop\n nop\n nop\n nop\n nop\n nop\n nop\n nop\n");
  asm("nop\n nop\n nop\n nop\n nop\n nop\n nop\n nop\n");

  asm("nop\n nop\n nop\n nop\n nop\n nop\n nop\n nop\n");
  asm("nop\n nop\n nop\n nop\n nop\n nop\n nop\n nop\n");

  asm("nop\n nop\n nop\n nop\n nop\n nop\n nop\n nop\n");
  asm("nop\n nop\n nop\n nop\n nop\n nop\n nop\n nop\n");

  for (int i = 0; i < 8; i++)
  {
    if (theByte & 01)
    {
      _SFR_BYTE(_SFR_IO8(portNumber)) |= pinMask;
    }
    else
    {
      _SFR_BYTE(_SFR_IO8(portNumber)) &= ~pinMask;
    }

    asm("nop\n nop\n nop\n nop\n nop\n nop\n nop\n nop\n");
    asm("nop\n nop\n nop\n nop\n nop\n nop\n nop\n nop\n");

    asm("nop\n nop\n nop\n nop\n nop\n nop\n nop\n nop\n");
    asm("nop\n nop\n nop\n nop\n nop\n nop\n nop\n nop\n");

    asm("nop\n nop\n nop\n nop\n nop\n nop\n nop\n nop\n");
    asm("nop\n nop\n nop\n nop\n nop\n nop\n nop\n nop\n");

    theByte >>= 1;
  }

  // the last thing we do is to write the pin to high
  // it will be the mark between bytes. (this break is have to be between 8 us and 1 sec)
  _SFR_BYTE(_SFR_IO8(portNumber)) |= pinMask;

  // reenable interrupts.
  sei();
}


void processDmx() {
	/***** sending the dmx signal *****/

  // sending the break (the break can be between 88us and 1sec)
  digitalWrite(sig, LOW);

  delayMicroseconds(100);

  dmxChannel[0] = 0;

  for (int count = 0; count <= 64; count++)
  {
	if (count < 64)
    	shiftDmxOut(sig, dmxChannel[count]);
	else 
		shiftDmxOut(sig,0);
  }



  /***** sending the dmx signal end *****/
}



void setup()
{
  Serial.begin(57600); 
  delay(100); 
  pinMode(sig, OUTPUT);
}

void loop()
{
  if (Serial.available()) {
    value = Serial.read();
    if ((0xD9 == value)&&(i==0))
      {
        i=1;
      }
    else if (i==1)
      {
           id=value;
           i=2;
      }
    else if ((i>=2)&&(i<6))
              {
              buffer[i]=value; 
              i=i+1;
              }
    if (i==6)
    {
      i=0;
      checksum = (buffer[2]+buffer[3]+buffer[4]);
      if ( buffer[5] == checksum ) //CHECKSUM (8 bits menos significativos)
        {
         if (id==0)
           {
             color[0] = buffer[2];
             color[1] = buffer[3];
             color[2] = buffer[4]; 
           }
           else
           {
             color[id*3+1] = buffer[2];
             color[id*3+2] = buffer[3];
             color[id*3+3] = buffer[4];
           }
        }
        else 
        {
          Serial.print(id ,BYTE);
          Serial.print(buffer[2] ,BYTE);
          Serial.print(buffer[3] ,BYTE);
          Serial.print(buffer[4] ,BYTE);
          Serial.print(buffer[5] ,BYTE);
          Serial.print(checksum ,BYTE);
        }
   }
  }
   if (i==0)
   {
     if (id==0) for (e=0; e<=2; e++) setDmxChannel(e,color[e]);
     else  for (e=id*3+1; e<=id*3+3; e++) setDmxChannel(e,color[e]);
     processDmx();
   }
}

int main(void)
{
	init();

	setup();
    
	for (;;)
		loop();
        
	return 0;
}