Arduino + Serato DJ = Seratuino

gistfile1.ino

/*
 *
 * DDS Sine Generator mit ATMEGS 168
 * Timer2 generates the  31250 KHz Clock Interrupt
 *
 * KHM 2009 /  Martin Nawrath
 * Kunsthochschule fuer Medien Koeln
 * Academy of Media Arts Cologne
 *
 * Edit: Daniele Polencic
 * 
 *

> Connect a potentiometer to +5Volt and Ground and the wiper to analog 0.
> Left Channel PIN11
> Right Channel PIN3

 */

#include "avr/pgmspace.h"

// table of 256 sine values / one sine period / stored in flash memory
PROGMEM  prog_uchar sine256[]  = {
  127,130,133,136,139,143,146,149,152,155,158,161,164,167,170,173,176,178,181,184,187,190,192,195,198,200,203,205,208,210,212,215,217,219,221,223,225,227,229,231,233,234,236,238,239,240,
  242,243,244,245,247,248,249,249,250,251,252,252,253,253,253,254,254,254,254,254,254,254,253,253,253,252,252,251,250,249,249,248,247,245,244,243,242,240,239,238,236,234,233,231,229,227,225,223,
  221,219,217,215,212,210,208,205,203,200,198,195,192,190,187,184,181,178,176,173,170,167,164,161,158,155,152,149,146,143,139,136,133,130,127,124,121,118,115,111,108,105,102,99,96,93,90,87,84,81,78,
  76,73,70,67,64,62,59,56,54,51,49,46,44,42,39,37,35,33,31,29,27,25,23,21,20,18,16,15,14,12,11,10,9,7,6,5,5,4,3,2,2,1,1,1,0,0,0,0,0,0,0,1,1,1,2,2,3,4,5,5,6,7,9,10,11,12,14,15,16,18,20,21,23,25,27,29,31,
  33,35,37,39,42,44,46,49,51,54,56,59,62,64,67,70,73,76,78,81,84,87,90,93,96,99,102,105,108,111,115,118,121,124

};
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))

int ledPin = 13;                 // LED pin 7
int testPin = 7;
int t2Pin = 6;
byte bb;

double dfreq;
// const double refclk=31372.549;  // =16MHz / 510
const double refclk=31376.6;      // measured

// variables used inside interrupt service declared as voilatile
volatile byte icnt;              // var inside interrupt
volatile byte icnt1;             // var inside interrupt
volatile byte icnt2;             // var inside interrupt
volatile byte c4ms;              // counter incremented all 4ms
volatile unsigned long phaccu;   // pahse accumulator
volatile unsigned long tword_m;  // dds tuning word m

void setup()
{
  pinMode(ledPin, OUTPUT);      // sets the digital pin as output
  Serial.begin(115200);        // connect to the serial port
  Serial.println("DDS Test");

  pinMode(6, OUTPUT);      // sets the digital pin as output
  pinMode(7, OUTPUT);      // sets the digital pin as output
  pinMode(11, OUTPUT);     // pin11= PWM  output / frequency output
  pinMode(3, OUTPUT);

  Setup_timer2();

  // disable interrupts to avoid timing distortion
  cbi (TIMSK0,TOIE0);              // disable Timer0 !!! delay() is now not available
  sbi (TIMSK2,TOIE2);              // enable Timer2 Interrupt

  dfreq=1000.0;                    // initial output frequency = 1000.o Hz
  tword_m=pow(2,32)*dfreq/refclk;  // calulate DDS new tuning word 

}
void loop()
{
  while(1) {
     if (c4ms > 250) {                 // timer / wait fou a full second
      c4ms=0;
      dfreq=analogRead(0);             // read Poti on analog pin 0 to adjust output frequency from 0..1023 Hz

      cbi (TIMSK2,TOIE2);              // disble Timer2 Interrupt
      tword_m=pow(2,32)*dfreq/refclk;  // calulate DDS new tuning word
      sbi (TIMSK2,TOIE2);              // enable Timer2 Interrupt 

      Serial.print(dfreq);
      Serial.print("  ");
      Serial.println(tword_m);
    }

   sbi(PORTD,6); // Test / set PORTD,7 high to observe timing with a scope
   cbi(PORTD,6); // Test /reset PORTD,7 high to observe timing with a scope
  }
 }
//******************************************************************
// timer2 setup
// set prscaler to 1, PWM mode to phase correct PWM,  16000000/510 = 31372.55 Hz clock
void Setup_timer2() {

// Timer2 Clock Prescaler to : 1
  sbi (TCCR2B, CS20);
  cbi (TCCR2B, CS21);
  cbi (TCCR2B, CS22);

  // Timer2 PWM Mode set to Phase Correct PWM
  cbi (TCCR2A, COM2A0);  // clear Compare Match
  sbi (TCCR2A, COM2A1);
  cbi (TCCR2A, COM2B0);  // clear Compare Match
  sbi (TCCR2A, COM2B1);
  

  sbi (TCCR2A, WGM20);  // Mode 1  / Phase Correct PWM
  cbi (TCCR2A, WGM21);
  cbi (TCCR2B, WGM22);
}

//******************************************************************
// Timer2 Interrupt Service at 31372,550 KHz = 32uSec
// this is the timebase REFCLOCK for the DDS generator
// FOUT = (M (REFCLK)) / (2 exp 32)
// runtime : 8 microseconds ( inclusive push and pop)
ISR(TIMER2_OVF_vect) {

  sbi(PORTD,7);          // Test / set PORTD,7 high to observe timing with a oscope

  phaccu=phaccu+tword_m; // soft DDS, phase accu with 32 bits
  icnt=phaccu >> 24;     // use upper 8 bits for phase accu as frequency information
                         // read value fron ROM sine table and send to PWM DAC
  icnt2 = icnt + 73;
  OCR2A=pgm_read_byte_near(sine256 + icnt);
  OCR2B=pgm_read_byte_near(sine256 + icnt2);  

  if(icnt1++ == 125) {  // increment variable c4ms all 4 milliseconds
    c4ms++;
    icnt1=0;
   }   

 cbi(PORTD,7);            // reset PORTD,7
}

I did this hack a long time ago, but I don't think I did that trick.
Instead, I used the audio output of the Arduino and connected to it to my laptop. The hack works with any software because the Arduino plays the same audio as the timecoded vinyl.

So long story short, this does not help you to have a USB midi device. This is a replacement for Serato timecode vinyl.

PROGMEM prog_uchar sine256[] = i have an error in this line like unchar is doesnot a type

Replace it. From "PROGMEM prog_uchar sine256[]" to "const PROGMEM uint16_t sine256[]"