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Next thing is to buy the transformer, and set this thing up. Hopefully i don’t have to spend hours debugging!

First was a trip to the local electronics store to see what i could get. Ended up coming out with a couple of kits and a heatsink.

Power Supply

The power supply is a simple kit from Jaycar – Power Supply Kit to suit SC-480. What i liked about this was that not only did it have +/- 40V rails for the power amp, it also has +/- 15V for powering a preamp. Perfect.

The only downside to this supply was the massive transformer it needs – 56V CT 134VA TRANSFORMER – 2.4A CENTRE TAPPED

Power Amp

The power amp i went for was the – SC-480 50W Amplifier

It just so hapened that the power supply was specifically designed for this amp. Bonus. The amp specs state that this is a 50W amp into 8ohms, but 70W into 4ohms which is how i will be running it, i think 70W is more than enough to shake the walls. I decided on a solid state power amp for ease of building and the fact that it was cheap.

The amp has low distortion and a good frequency range. Although all this means nothing to a guitar amp, so the desired sound will hopefully come from a well designed pre amp.

Again, the only downside i could see was that it needed a massive heatsink – Black Heatsink – DIECAST

Assembly

This is as far as i have come with the amp so far. Been thinking about cabinet and speaker design aswel as pre amp design. But for the time being i am assembling these two kits and researching the rest. More details will be posted soon.

Read more for code

/*
COMAND STRUCTURE
Single byte commands are received by the arduino

byte structure: xxyy zzzz

: xx bits – octave
: yy bits – wave shape
: zz bits – note

*/
#include “TimerOne.h”
#include <avr/pgmspace.h>

prog_uchar SINE_TABLE[] PROGMEM=
{
0×80,0×83,0×86,0×89,0x8c,0x8f,0×92,0×95,0×98,0x9c,0x9f,0xa2,0xa5,0xa8,0xab,0xae,
0xb0,0xb3,0xb6,0xb9,0xbc,0xbf,0xc1,0xc4,0xc7,0xc9,0xcc,0xce,0xd1,0xd3,0xd5,0xd8,
0xda,0xdc,0xde,0xe0,0xe2,0xe4,0xe6,0xe8,0xea,0xec,0xed,0xef,0xf0,0xf2,0xf3,0xf5,
0xf6,0xf7,0xf8,0xf9,0xfa,0xfb,0xfc,0xfc,0xfd,0xfe,0xfe,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xfe,0xfe,0xfd,0xfc,0xfc,0xfb,0xfa,0xf9,0xf8,0xf7,
0xf6,0xf5,0xf3,0xf2,0xf0,0xef,0xed,0xec,0xea,0xe8,0xe6,0xe4,0xe2,0xe0,0xde,0xdc,
0xda,0xd8,0xd5,0xd3,0xd1,0xce,0xcc,0xc9,0xc7,0xc4,0xc1,0xbf,0xbc,0xb9,0xb6,0xb3,
0xb0,0xae,0xab,0xa8,0xa5,0xa2,0x9f,0x9c,0×98,0×95,0×92,0x8f,0x8c,0×89,0×86,0×83,
0×80,0x7c,0×79,0×76,0×73,0×70,0x6d,0x6a,0×67,0×63,0×60,0x5d,0x5a,0×57,0×54,0×51,
0x4f,0x4c,0×49,0×46,0×43,0×40,0x3e,0x3b,0×38,0×36,0×33,0×31,0x2e,0x2c,0x2a,0×27,
0×25,0×23,0×21,0x1f,0x1d,0x1b,0×19,0×17,0×15,0×13,0×12,0×10,0x0f,0x0d,0x0c,0x0a,
0×09,0×08,0×07,0×06,0×05,0×04,0×03,0×03,0×02,0×01,0×01,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×01,0×01,0×02,0×03,0×03,0×04,0×05,0×06,0×07,0×08,
0×09,0x0a,0x0c,0x0d,0x0f,0×10,0×12,0×13,0×15,0×17,0×19,0x1b,0x1d,0x1f,0×21,0×23,
0×25,0×27,0x2a,0x2c,0x2e,0×31,0×33,0×36,0×38,0x3b,0x3e,0×40,0×43,0×46,0×49,0x4c,
0x4f,0×51,0×54,0×57,0x5a,0x5d,0×60,0×63,0×67,0x6a,0x6d,0×70,0×73,0×76,0×79,0x7c
};

prog_uchar SAW_TABLE[] PROGMEM=
{
0×00,0×01,0×02,0×03,0×04,0×05,0×06,0×07,0×08,0×09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
0×10,0×11,0×12,0×13,0×14,0×15,0×16,0×17,0×18,0×19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f,
0×20,0×21,0×22,0×23,0×24,0×25,0×26,0×27,0×28,0×29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f,
0×30,0×31,0×32,0×33,0×34,0×35,0×36,0×37,0×38,0×39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f,
0×40,0×41,0×42,0×43,0×44,0×45,0×46,0×47,0×48,0×49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f,
0×50,0×51,0×52,0×53,0×54,0×55,0×56,0×57,0×58,0×59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f,
0×60,0×61,0×62,0×63,0×64,0×65,0×66,0×67,0×68,0×69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f,
0×70,0×71,0×72,0×73,0×74,0×75,0×76,0×77,0×78,0×79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f,
0×80,0×81,0×82,0×83,0×84,0×85,0×86,0×87,0×88,0×89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f,
0×90,0×91,0×92,0×93,0×94,0×95,0×96,0×97,0×98,0×99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f,
0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7,0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf,
0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7,0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf,
0xc0,0xc1,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,0xc8,0xc9,0xca,0xcb,0xcc,0xcd,0xce,0xcf,
0xd0,0xd1,0xd2,0xd3,0xd4,0xd5,0xd6,0xd7,0xd8,0xd9,0xda,0xdb,0xdc,0xdd,0xde,0xdf,
0xe0,0xe1,0xe2,0xe3,0xe4,0xe5,0xe6,0xe7,0xe8,0xe9,0xea,0xeb,0xec,0xed,0xee,0xef,
0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7,0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff
};

prog_uchar SQUARE_TABLE[] PROGMEM=
{
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff
};

prog_uchar TRIANGLE_TABLE[] PROGMEM=
{
0×00,0×02,0×04,0×06,0×08,0x0a,0x0c,0x0e,0×10,0×12,0×14,0×16,0×18,0x1a,0x1c,0x1e,
0×20,0×22,0×24,0×26,0×28,0x2a,0x2c,0x2e,0×30,0×32,0×34,0×36,0×38,0x3a,0x3c,0x3e,
0×40,0×42,0×44,0×46,0×48,0x4a,0x4c,0x4e,0×50,0×52,0×54,0×56,0×58,0x5a,0x5c,0x5e,
0×60,0×62,0×64,0×66,0×68,0x6a,0x6c,0x6e,0×70,0×72,0×74,0×76,0×78,0x7a,0x7c,0x7e,
0×80,0×82,0×84,0×86,0×88,0x8a,0x8c,0x8e,0×90,0×92,0×94,0×96,0×98,0x9a,0x9c,0x9e,
0xa0,0xa2,0xa4,0xa6,0xa8,0xaa,0xac,0xae,0xb0,0xb2,0xb4,0xb6,0xb8,0xba,0xbc,0xbe,
0xc0,0xc2,0xc4,0xc6,0xc8,0xca,0xcc,0xce,0xd0,0xd2,0xd4,0xd6,0xd8,0xda,0xdc,0xde,
0xe0,0xe2,0xe4,0xe6,0xe8,0xea,0xec,0xee,0xf0,0xf2,0xf4,0xf6,0xf8,0xfa,0xfc,0xfe,
0xff,0xfd,0xfb,0xf9,0xf7,0xf5,0xf3,0xf1,0xef,0xef,0xeb,0xe9,0xe7,0xe5,0xe3,0xe1,
0xdf,0xdd,0xdb,0xd9,0xd7,0xd5,0xd3,0xd1,0xcf,0xcf,0xcb,0xc9,0xc7,0xc5,0xc3,0xc1,
0xbf,0xbd,0xbb,0xb9,0xb7,0xb5,0xb3,0xb1,0xaf,0xaf,0xab,0xa9,0xa7,0xa5,0xa3,0xa1,
0x9f,0x9d,0x9b,0×99,0×97,0×95,0×93,0×91,0x8f,0x8f,0x8b,0×89,0×87,0×85,0×83,0×81,
0x7f,0x7d,0x7b,0×79,0×77,0×75,0×73,0×71,0x6f,0x6f,0x6b,0×69,0×67,0×65,0×63,0×61,
0x5f,0x5d,0x5b,0×59,0×57,0×55,0×53,0×51,0x4f,0x4f,0x4b,0×49,0×47,0×45,0×43,0×41,
0x3f,0x3d,0x3b,0×39,0×37,0×35,0×33,0×31,0x2f,0x2f,0x2b,0×29,0×27,0×25,0×23,0×21,
0x1f,0x1d,0x1b,0×19,0×17,0×15,0×13,0×11,0x0f,0x0f,0x0b,0×09,0×07,0×05,0×03,0×01
};

byte *table;
byte key;
byte x1;
//byte y0;
//byte y1;
//byte m;
volatile unsigned int phase;
volatile unsigned int phaseDelta;
//unsigned int note[] = {
// 0, 264,275,293.33,309.37,330,352,366.67,396,412.5,440.00,469.34,495};
unsigned int note[] = {
0, 131, 139, 147, 156, 165, 175, 185, 196, 208, 220, 233, 247 };

void setup()
{
//setup

//portd (dac) setup
//portd uses digital pins 0 – 7
DDRD = DDRD | B11111100; //bits 2 – 7
DDRB = DDRB | B00000011; //bits 0 and 1

//timer setup for 16.384khz (61us)
Timer1.initialize(61);
Timer1.attachInterrupt(Timer_ISR);

//serial setup
Serial.begin(9600);
}

void loop()
{
byte xx;
byte yy;
byte zzzz;
//main loop

if (Serial.available() > 0)
{
key = Serial.read(); //get byte
Serial.print(key,DEC); //acknowledge byte

zzzz = key & 0x0F; //break byte into command
key >>= 4; //and its params
yy = key & 0×03;
key >>= 2;
xx = key & 0×03;
key = 0;

//delta = (SAMP / FREQ) * note
//SAMP/FREQ = 4 which is the same as shift left 2 bits
phaseDelta = (note[zzzz] << 2) << xx;

if (yy == 0) //sine wave
{
table = SINE_TABLE;
}
else if (yy == 1) //saw tooth
{
table = SAW_TABLE;
}
else if (yy == 2) //square
{
table = SQUARE_TABLE;
}
else if (yy == 3) //triangle
{
table = TRIANGLE_TABLE;
}
}
}

void Timer_ISR()
{
//
phase += phaseDelta;

x1 = pgm_read_byte_near(table+(phase>>8));

PORTD &= 0×03;
PORTD |= x1 & 0xFC;
PORTB &= 0xFC;
PORTB |= x1 & 0×03;
}

The synth is based on the Direct Digital Synthesis method of producing waveforms digitally. I aim to get around 100Hz to ~4kHz operation out of it but im sure it is capable of frequencies up to around 50kHz. But this can be determined when the source has been verified and is working.

The source code for the Arduino has been written and attached below, but i have not verified it yet (my board is still in the mail). The DAC is intended to be connected to the Arduino board as follows:

Bit 0 (LSB) : Digital Pin 8

Bit 1 : Digital Pin 9

Bit 2 : Digital Pin 2

Bit 3 : Digital Pin 3

Bit 4 : Digital Pin 4

Bit 5 : Digital Pin 5

Bit 6 : Digital Pin 6

Bit 7 (MSB) : Digital Pin 7

I will provide more information and results when my board arrives

The source can be found by reading more

const byte SINE_TABLE[]=
{
0×80,0×83,0×86,0×89,0x8c,0x8f,0×92,0×95,0×98,0x9c,0x9f,0xa2,0xa5,0xa8,0xab,0xae,
0xb0,0xb3,0xb6,0xb9,0xbc,0xbf,0xc1,0xc4,0xc7,0xc9,0xcc,0xce,0xd1,0xd3,0xd5,0xd8,
0xda,0xdc,0xde,0xe0,0xe2,0xe4,0xe6,0xe8,0xea,0xec,0xed,0xef,0xf0,0xf2,0xf3,0xf5,
0xf6,0xf7,0xf8,0xf9,0xfa,0xfb,0xfc,0xfc,0xfd,0xfe,0xfe,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xfe,0xfe,0xfd,0xfc,0xfc,0xfb,0xfa,0xf9,0xf8,0xf7,
0xf6,0xf5,0xf3,0xf2,0xf0,0xef,0xed,0xec,0xea,0xe8,0xe6,0xe4,0xe2,0xe0,0xde,0xdc,
0xda,0xd8,0xd5,0xd3,0xd1,0xce,0xcc,0xc9,0xc7,0xc4,0xc1,0xbf,0xbc,0xb9,0xb6,0xb3,
0xb0,0xae,0xab,0xa8,0xa5,0xa2,0x9f,0x9c,0×98,0×95,0×92,0x8f,0x8c,0×89,0×86,0×83,
0×80,0x7c,0×79,0×76,0×73,0×70,0x6d,0x6a,0×67,0×63,0×60,0x5d,0x5a,0×57,0×54,0×51,
0x4f,0x4c,0×49,0×46,0×43,0×40,0x3e,0x3b,0×38,0×36,0×33,0×31,0x2e,0x2c,0x2a,0×27,
0×25,0×23,0×21,0x1f,0x1d,0x1b,0×19,0×17,0×15,0×13,0×12,0×10,0x0f,0x0d,0x0c,0x0a,
0×09,0×08,0×07,0×06,0×05,0×04,0×03,0×03,0×02,0×01,0×01,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×01,0×01,0×02,0×03,0×03,0×04,0×05,0×06,0×07,0×08,
0×09,0x0a,0x0c,0x0d,0x0f,0×10,0×12,0×13,0×15,0×17,0×19,0x1b,0x1d,0x1f,0×21,0×23,
0×25,0×27,0x2a,0x2c,0x2e,0×31,0×33,0×36,0×38,0x3b,0x3e,0×40,0×43,0×46,0×49,0x4c,
0x4f,0×51,0×54,0×57,0x5a,0x5d,0×60,0×63,0×67,0x6a,0x6d,0×70,0×73,0×76,0×79,0x7c
};

const byte SAW_TABLE[]=
{
0×00,0×01,0×02,0×03,0×04,0×05,0×06,0×07,0×08,0×09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
0×10,0×11,0×12,0×13,0×14,0×15,0×16,0×17,0×18,0×19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f,
0×20,0×21,0×22,0×23,0×24,0×25,0×26,0×27,0×28,0×29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f,
0×30,0×31,0×32,0×33,0×34,0×35,0×36,0×37,0×38,0×39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f,
0×40,0×41,0×42,0×43,0×44,0×45,0×46,0×47,0×48,0×49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f,
0×50,0×51,0×52,0×53,0×54,0×55,0×56,0×57,0×58,0×59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f,
0×60,0×61,0×62,0×63,0×64,0×65,0×66,0×67,0×68,0×69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f,
0×70,0×71,0×72,0×73,0×74,0×75,0×76,0×77,0×78,0×79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f,
0×80,0×81,0×82,0×83,0×84,0×85,0×86,0×87,0×88,0×89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f,
0×90,0×91,0×92,0×93,0×94,0×95,0×96,0×97,0×98,0×99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f,
0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7,0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf,
0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7,0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf,
0xc0,0xc1,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,0xc8,0xc9,0xca,0xcb,0xcc,0xcd,0xce,0xcf,
0xd0,0xd1,0xd2,0xd3,0xd4,0xd5,0xd6,0xd7,0xd8,0xd9,0xda,0xdb,0xdc,0xdd,0xde,0xdf,
0xe0,0xe1,0xe2,0xe3,0xe4,0xe5,0xe6,0xe7,0xe8,0xe9,0xea,0xeb,0xec,0xed,0xee,0xef,
0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7,0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff
};

const byte SQUARE_TABLE[]=
{
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,0×00,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff
};

const byte TRIANGLE_TABLE[]=
{
0×00,0×02,0×04,0×06,0×08,0x0a,0x0c,0x0e,0×10,0×12,0×14,0×16,0×18,0x1a,0x1c,0x1e,
0×20,0×22,0×24,0×26,0×28,0x2a,0x2c,0x2e,0×30,0×32,0×34,0×36,0×38,0x3a,0x3c,0x3e,
0×40,0×42,0×44,0×46,0×48,0x4a,0x4c,0x4e,0×50,0×52,0×54,0×56,0×58,0x5a,0x5c,0x5e,
0×60,0×62,0×64,0×66,0×68,0x6a,0x6c,0x6e,0×70,0×72,0×74,0×76,0×78,0x7a,0x7c,0x7e,
0×80,0×82,0×84,0×86,0×88,0x8a,0x8c,0x8e,0×90,0×92,0×94,0×96,0×98,0x9a,0x9c,0x9e,
0xa0,0xa2,0xa4,0xa6,0xa8,0xaa,0xac,0xae,0xb0,0xb2,0xb4,0xb6,0xb8,0xba,0xbc,0xbe,
0xc0,0xc2,0xc4,0xc6,0xc8,0xca,0xcc,0xce,0xd0,0xd2,0xd4,0xd6,0xd8,0xda,0xdc,0xde,
0xe0,0xe2,0xe4,0xe6,0xe8,0xea,0xec,0xee,0xf0,0xf2,0xf4,0xf6,0xf8,0xfa,0xfc,0xfe,
0xff,0xfd,0xfb,0xf9,0xf7,0xf5,0xf3,0xf1,0xef,0xef,0xeb,0xe9,0xe7,0xe5,0xe3,0xe1,
0xdf,0xdd,0xdb,0xd9,0xd7,0xd5,0xd3,0xd1,0xcf,0xcf,0xcb,0xc9,0xc7,0xc5,0xc3,0xc1,
0xbf,0xbd,0xbb,0xb9,0xb7,0xb5,0xb3,0xb1,0xaf,0xaf,0xab,0xa9,0xa7,0xa5,0xa3,0xa1,
0x9f,0x9d,0x9b,0×99,0×97,0×95,0×93,0×91,0x8f,0x8f,0x8b,0×89,0×87,0×85,0×83,0×81,
0x7f,0x7d,0x7b,0×79,0×77,0×75,0×73,0×71,0x6f,0x6f,0x6b,0×69,0×67,0×65,0×63,0×61,
0x5f,0x5d,0x5b,0×59,0×57,0×55,0×53,0×51,0x4f,0x4f,0x4b,0×49,0×47,0×45,0×43,0×41,
0x3f,0x3d,0x3b,0×39,0×37,0×35,0×33,0×31,0x2f,0x2f,0x2b,0×29,0×27,0×25,0×23,0×21,
0x1f,0x1d,0x1b,0×19,0×17,0×15,0×13,0×11,0x0f,0x0f,0x0b,0×09,0×07,0×05,0×03,0×01
};

#define FREQ 2400
#define SAMP 65536 //2^16

#include “TimerOne.h”

byte key;
byte wave;
byte x1;
byte y0;
byte y1;
byte m;
unsigned int phase;
unsigned int phaseDelta;
unsigned int note[] = {
0, 264,275,293.33,309.37,330,352,366.67,396,412.5,440.00,469.34,495};

void setup()
{
//setup

//portd (dac) setup
//portd uses digital pins 0 – 7
DDRD = DDRD | B11111100; //bits 2 – 7
DDRB = DDRB | B00000011; //bits 0 and 1

//timer setup for 8khz (125us)
Timer1.initialize(125);
Timer1.attachInterrupt(Timer_ISR);

//serial setup
Serial.begin(9600);
}

void loop()
{
//main loop
if (Serial.available() > 0)
{
key = Serial.read();
}

/*
COMAND STRUCTURE
Single byte commands are received my the uC

byte structure: xxyy zzzz

xx bits – command
- 00: note
: yy bits – octave
: zz bits – note
- 01: wave shape
: yy bits – wave shape
: zz bits – not used
- 10:
- 11:
*/

//note command
if(((key >> 6) & 0×03) == 0)
{
phaseDelta = calcPhaseDelta(note[key & 0x0F],(key >> 4) & 0×03);
}
if(((key >> 6) & 0×03) == 1)
{
wave = (key >> 4) & 0×03;
}

}

void Timer_ISR()
{
//
byte index;

phase += phaseDelta;
index = (byte)(phase>>8);

if (wave == 0) //sine wave
{
x1 = SINE_TABLE[index];
}
else if (wave == 1) //saw tooth
{
x1 = SAW_TABLE[index];
}
else if (wave == 2) //square
{
x1 = SQUARE_TABLE[index];
}
else if (wave == 3) //triangle
{
x1 = TRIANGLE_TABLE[index];
}

PORTD &= 0×03;
PORTD |= x1 & 0xFC;
PORTB &= 0xFC;
PORTB |= x1 & 0×03;
}

unsigned int calcPhaseDelta(int note, byte oct)
{
//
unsigned int delta = 0;

delta = (SAMP / FREQ) * note;
return delta;
}