Question

I was trying to build a basic theremin with my Arduino for didactic purpose.
My idea was reading a potentiometer for the volume and a photoresistor for the pitch.

My code right now is:

 int piezoPin = 5;
 int sensorPin = 1;
 int potPin = 2;

 int sogliaMinima = 20;
 int sogliaMassima = 160;

 void setup () {
   pinMode (piezoPin, OUTPUT);
   Serial.begin (9600);
 }

 void loop () {
  // first block of code working
  int potLevel = analogRead (potPin);
  int levelVolume = map (potLevel, 0, 1022, 0, 170);
  analogWrite (piezoPin, levelVolume);


  // second block of code working
  int sensorValue = analogRead (sensorPin);
  int pitchLevel = map (sensorValue, sogliaMinima, sogliaMassima, 100, 1000);
  tone (piezoPin, pitchLevel);
 }

This is not working, and it’s a software issue not a circuit mistake. Both first block and second block are working if commenting one of them, but don’t work together. So my question is: can I use tone() and analogWrite on the same pin?

Answer 1

You are correct. You can’t use both functions on the same pin. The two functions analogWrite and tone both attempt to control the pin with a PWM signal. Doing both in sequence changes their defaults. For analogWrite, the tone is 490Hz.