/*
 * DMX fade for arduino 008
 * based on the code of Tomek Ness and D. Cuartielles
 *
 * adapted to arduino 008 by Peter Szakal and Gabor Papp
 * http://nextlab.hu
 */

#include "pins_arduino.h"

int sig = 8; // signal

/* 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 setup()
{
  pinMode(sig, OUTPUT);
  Serial.begin(9600);
}

int value1 = 255;
int value2 = 0;
int value3 = 0;

void loop()
{
  /***** sending the dmx signal *****/
  
    // sending the break (the break can be between 88us and 1sec)
//    digitalWrite(sig, LOW);
//    delayMicroseconds(1000);
//    // sending the start byte
//    shiftDmxOut(sig, 0);
//    for (int count = 1; count <= 512; count = count+3)
//    {
//      shiftDmxOut(sig, value1);
//      shiftDmxOut(sig, value2);
//      shiftDmxOut(sig, value3);
//      //Serial.println(value);
//    }

  for (value1 = 1; value1 < 255; value1++)
  {
    // sending the break (the break can be between 88us and 1sec)
    digitalWrite(sig, LOW);
    delayMicroseconds(1000);
    // sending the start byte
    shiftDmxOut(sig, 0);
    for (int count = 1; count <= 512; count = count+3)
    {
      shiftDmxOut(sig, value1);
      shiftDmxOut(sig, value2);
      shiftDmxOut(sig, value3);
      //Serial.println(value);
    }
  }
  
  for (value2 = 1; value2 < 255; value2++)
  {
    // sending the break (the break can be between 88us and 1sec)
    digitalWrite(sig, LOW);
    delayMicroseconds(1000);
    // sending the start byte
    shiftDmxOut(sig, 0);
    for (int count = 1; count <= 512; count = count+3)
    {
      shiftDmxOut(sig, value1);
      shiftDmxOut(sig, value2);
      shiftDmxOut(sig, value3);
      //Serial.println(value);
    }
  }
  
  for (value3 = 1; value3 < 255; value3++)
  {
    // sending the break (the break can be between 88us and 1sec)
    digitalWrite(sig, LOW);
    delayMicroseconds(1000);
    // sending the start byte
    shiftDmxOut(sig, 0);
    for (int count = 1; count <= 512; count = count+3)
    {
      shiftDmxOut(sig, value1);
      shiftDmxOut(sig, value2);
      shiftDmxOut(sig, value3);
      //Serial.println(value);
    }
  }
  
  for (value2 = 255; value2 > 0; value2--)
  {
    // sending the break (the break can be between 88us and 1sec)
    digitalWrite(sig, LOW);
    delayMicroseconds(1000);
    // sending the start byte
    shiftDmxOut(sig, 0);
    for (int count = 1; count <= 512; count = count+3)
    {
      shiftDmxOut(sig, value1);
      shiftDmxOut(sig, value2);
      shiftDmxOut(sig, value3);
      //Serial.println(value);
    }
  }
  
  for (value3 = 255; value3 > 0; value3--)
  {
    // sending the break (the break can be between 88us and 1sec)
    digitalWrite(sig, LOW);
    delayMicroseconds(1000);
    // sending the start byte
    shiftDmxOut(sig, 0);
    for (int count = 1; count <= 512; count = count+3)
    {
      shiftDmxOut(sig, value1);
      shiftDmxOut(sig, value2);
      shiftDmxOut(sig, value3);
      //Serial.println(value);
    }
  }
  
  for (value1 = 255; value1 > 0; value1--)
  {
    // sending the break (the break can be between 88us and 1sec)
    digitalWrite(sig, LOW);
    delayMicroseconds(1000);
    // sending the start byte
    shiftDmxOut(sig, 0);
    for (int count = 1; count <= 512; count = count+3)
    {
      shiftDmxOut(sig, value1);
      shiftDmxOut(sig, value2);
      shiftDmxOut(sig, value3);
      //Serial.println(value);
    }
  }
  
}