/*
 * DACmulti2a
 * Arduino Diecimila sketch
 * August 4, 2009, G. Forrest Cook
 * Released under the GPLv3 license.
 *
 * Modulate an 8 bit DAC with one of three arbitrary waveforms.
 * Use the reset button to step to the next waveform.
 * The EEPROM remembers the previously selected waveform on power-up.
 * An R-C array is used on an analog input pin to detect the first boot.
 * An RGB LED displays Yellow, Cyan or Magenta for pattern 1, 2 or 3.
 */

#include <EEPROM.h>

byte eepromval;
int RedPin = 8;
int GreenPin = 9;		// RGB LEDs (PB0-2)
int BluePin = 10;
int WaveNum = 0;
int dtime;
int indx = 0;
#define YELLOW 3
#define CYAN 6
#define MAGENTA 5
#define STEPS1 256 // 1.5 exp sine wave
#define STEPS2 256 // 1.7 exp sine wave
#define STEPS3 256 // 2.1 exp sine wave

byte wavetable1[STEPS1] = {0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 19, 21, 22, 24, 25, 27, 29, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 51, 53, 55, 58, 60, 62, 65, 68, 70, 73, 75, 78, 81, 84, 87, 90, 93, 95, 98, 102, 105, 108, 111, 114, 117, 120, 123, 127, 130, 133, 136, 140, 143, 146, 150, 153, 156, 159, 163, 166, 169, 172, 176, 179, 182, 185, 188, 191, 194, 197, 200, 203, 206, 209, 211, 214, 217, 219, 222, 224, 227, 229, 231, 233, 235, 237, 239, 241, 242, 244, 245, 247, 248, 249, 250, 251, 252, 252, 253, 254, 254, 254, 254, 255, 254, 254, 254, 254, 253, 252, 252, 251, 250, 249, 248, 247, 245, 244, 242, 241, 239, 237, 235, 233, 231, 229, 227, 224, 222, 219, 217, 214, 211, 209, 206, 203, 200, 197, 194, 191, 188, 185, 182, 179, 176, 172, 169, 166, 163, 159, 156, 153, 150, 146, 143, 140, 136, 133, 130, 127, 123, 120, 117, 114, 111, 108, 105, 102, 98, 95, 93, 90, 87, 84, 81, 78, 75, 73, 70, 68, 65, 62, 60, 58, 55, 53, 51, 48, 46, 44, 42, 40, 38, 36, 34, 32, 30, 29, 27, 25, 24, 22, 21, 19, 18, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 4, 3, 3, 2, 2, 1, 1, 0, 0, 0, 0, 0};
byte wavetable2[STEPS2] = {0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 3, 3, 4, 4, 5, 6, 7, 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 18, 19, 21, 22, 24, 25, 27, 28, 30, 32, 34, 35, 37, 39, 41, 43, 45, 47, 50, 52, 54, 56, 59, 61, 64, 66, 69, 71, 74, 77, 80, 82, 85, 88, 91, 94, 97, 100, 103, 106, 109, 113, 116, 119, 122, 126, 129, 132, 136, 139, 142, 146, 149, 152, 156, 159, 163, 166, 169, 173, 176, 179, 183, 186, 189, 192, 195, 198, 202, 205, 207, 210, 213, 216, 219, 221, 224, 226, 229, 231, 233, 235, 237, 239, 241, 243, 244, 246, 247, 248, 250, 251, 252, 252, 253, 254, 254, 254, 255, 255, 255, 254, 254, 254, 253, 252, 252, 251, 250, 248, 247, 246, 244, 243, 241, 239, 237, 235, 233, 231, 229, 226, 224, 221, 219, 216, 213, 210, 207, 205, 202, 198, 195, 192, 189, 186, 183, 179, 176, 173, 169, 166, 163, 159, 156, 152, 149, 146, 142, 139, 136, 132, 129, 126, 122, 119, 116, 113, 109, 106, 103, 100, 97, 94, 91, 88, 85, 82, 80, 77, 74, 71, 69, 66, 64, 61, 59, 56, 54, 52, 50, 47, 45, 43, 41, 39, 37, 35, 34, 32, 30, 28, 27, 25, 24, 22, 21, 19, 18, 17, 16, 14, 13, 12, 11, 10, 9, 8, 7, 7, 6, 5, 4, 4, 3, 3, 2, 2, 1, 1, 1, 0, 0, 0, 0, 0};
byte wavetable3[STEPS3] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 4, 4, 5, 6, 6, 7, 8, 9, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 22, 23, 24, 26, 27, 29, 30, 32, 34, 36, 37, 39, 41, 43, 45, 47, 49, 51, 54, 56, 58, 61, 63, 66, 68, 71, 74, 76, 79, 82, 85, 88, 91, 94, 97, 100, 103, 107, 110, 113, 116, 120, 123, 127, 130, 134, 137, 141, 144, 148, 152, 155, 159, 162, 166, 170, 173, 177, 180, 184, 187, 191, 194, 197, 201, 204, 207, 210, 213, 216, 219, 222, 225, 228, 230, 233, 235, 237, 239, 241, 243, 245, 246, 248, 249, 251, 252, 253, 253, 254, 255, 255, 255, 255, 255, 255, 255, 254, 253, 253, 252, 251, 249, 248, 246, 245, 243, 241, 239, 237, 235, 233, 230, 228, 225, 222, 219, 216, 213, 210, 207, 204, 201, 197, 194, 191, 187, 184, 180, 177, 173, 170, 166, 162, 159, 155, 152, 148, 144, 141, 137, 134, 130, 127, 123, 120, 116, 113, 110, 107, 103, 100, 97, 94, 91, 88, 85, 82, 79, 76, 74, 71, 68, 66, 63, 61, 58, 56, 54, 51, 49, 47, 45, 43, 41, 39, 37, 36, 34, 32, 30, 29, 27, 26, 24, 23, 22, 20, 19, 18, 17, 15, 14, 13, 12, 11, 10, 9, 9, 8, 7, 6, 6, 5, 4, 4, 3, 3, 2, 2, 2, 1, 1, 1, 0, 0, 0, 0, 0, 0};

void setup()
{
  DDRB = 7;			// Set port B to outputs for RGB LED.
  DDRD = 255;			// Set port D to all outputs for DAC.

  if (analogRead(0) > 512) // Not first boot, step values.
  {
    eepromval = EEPROM.read(0);

    if (eepromval == 0)
    {
      EEPROM.write(0, 1);
      WaveNum = 1;
      PORTB = CYAN;
    }
    else if (eepromval == 1)
    {
      EEPROM.write(0, 2);
      WaveNum = 2;
      PORTB = MAGENTA;
    }
    else
    {
      EEPROM.write(0, 0);
      WaveNum = 0;
      PORTB = YELLOW;
    }
  }
  else		// first boot, don't change state.
  {
    eepromval = EEPROM.read(0);

    if (eepromval == 0)
    {
      WaveNum = 0;
      PORTB = YELLOW;
    }
    else if (eepromval == 1)
    {
      WaveNum = 1;
      PORTB = CYAN;
    }
    else
    {
      WaveNum = 2;
      PORTB = MAGENTA;
    }
  }
}

void loop()
{
  if (WaveNum == 0)	// Pick one of the wave tables and loop infinitely.
  {
    while (1)
    {
      PORTD = wavetable1[indx];
      dtime = (analogRead(1) + 5) * 8;
      delayMicroseconds(dtime);

      indx++;

      if (indx >= STEPS1)
        indx = 0;
    }
  }
  else if (WaveNum == 1)
  {
    while (1)
    {
      PORTD = wavetable2[indx];
      dtime = (analogRead(1) + 5) * 8;
      delayMicroseconds(dtime);

      indx++;

      if (indx >= STEPS2)
        indx = 0;
    }
  }
  else
  {
    while (1)
    {
      PORTD = wavetable3[indx];
      dtime = (analogRead(1) + 5) * 8;
      delayMicroseconds(dtime);

      indx++;

      if (indx >= STEPS3)
        indx = 0;
    }
  }
}