Arduino Synth

Arduino Synth is a project that consists of creating an 8-bit capacitive synthesizer.

IntermediateShowcase (no instructions)2 hours4,690

Things used in this project

Hardware components

Arduino UNO

Microchip ATmega328

USB-A to B Cable

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)

Story

The Arduino Synth project was developed at the National Institute of Applied Science and Technology (INSAT) in Spring 2019

Visit Karem's personal portfolio: karembenchikha.me

Visit Oussama's LinkedIn https://www.linkedin.com/in/oussamaettaouil/

Check the Project on GitHub: https://github.com/KaremBenChikha/ArduinoSynth

Video

This is a video that demonstrates how the capacitive synthesizer is working.

Demonstration of our Arduino Synth

Electronics

During this project, we will need:

ATmega328-PU
3.5mm audio jack
ATmega328-PU holder
PCB copper
USB port type B
1KΩ resistance
1 Quartz 20 MHz

Arduino Programming

Program the ATmega328-PU using the Arduino Uno, then take it carefully as shown in the picture to install it on our new capacitive synth.

Take the Atmega328-PU after programming it

Code

Synthesizer.ino

/*
  Synthesizer
  creating sound from electronics
  
  This example is part of the Fritzing Creator Kit: www.fritzing.org/creator-kit.
*/

int buzzerPin = 8;                             // piezo pin declaration
int potPin1 = 0;                               // potentiometer 1 pin declaration
int potPin2 = 1;                               // potentiometer 2 pin declaration

int toneHeight;                                // store the tone height
int lfo;                                       // store the frequency speed

/* lfo is a "low frequency oscillator" - so a frequency change depending on time */

void setup() {
  pinMode(buzzerPin, OUTPUT);                  // buzzerPin as output
}

void play(int myToneHeight) {                  // play method
    digitalWrite(buzzerPin, HIGH);             // piezo is switched on
    delayMicroseconds(myToneHeight);           // stopping time influenced by toneHeight 
    digitalWrite(buzzerPin, LOW);              // piezo is switched off
    delayMicroseconds(myToneHeight);           // stopping time influenced by toneHeight 
}

void loop() {
  toneHeight=analogRead(potPin1);              // toneheight is value of potentiometer 1
  lfo=analogRead(potPin2);                     // lfo is value of potentiometer 2
  
  for (int i = (lfo/10); i > 0; i--) {         // toneheight rising depending on lfo
    play(toneHeight);                          // execute play method
  }
  delayMicroseconds(lfo);                      // break
  for (int i = 0; i < lfo/10; i++) {           // toneheight sinking depending on lfo
    play(toneHeight);                          // execute play method
  }
}