Arduino Uno volume control using two potentiometers

Projects General Guidance
1

I am trying to control the volume of a piezo speaker using two potentiometers. The first one will control the volume of the speaker from minimum to maximum volume. After the value of the first potentiometer is chosen, the second potentiometer will actuate the volume between the volume set by the first potentiometer and max volume. Here is my code so far:

#include "pitches.h"

const int speakerPin = 9;
const int pot1Pin = A0;
const int pot2Pin = A1;

// An array of notes for the melody
int melody[] = {NOTE_E4, NOTE_D4, NOTE_C4, NOTE_D4, NOTE_E4, NOTE_E4, NOTE_E4,
NOTE_D4, NOTE_D4, NOTE_D4, NOTE_E4, NOTE_G4, NOTE_G4,
NOTE_E4, NOTE_D4, NOTE_C4, NOTE_D4, NOTE_E4, NOTE_E4, NOTE_E4,
NOTE_E4, NOTE_D4, NOTE_D4, NOTE_E4, NOTE_D4, NOTE_C4};

// The duration of each note in the melody
int noteDurations[] = {4, 4, 4, 4, 4, 4, 2,
4, 4, 4, 4, 4, 2,
4, 4, 4, 4, 4, 4, 2,
4, 4, 4, 4, 4, 2};

int tempo = 100; // The tempo of the melody

void setup() {
pinMode(speakerPin, OUTPUT); // Set the speaker pin as an output
}

void loop() {
int desiredVolume = analogRead(pot1Pin); // Read the value from the first potentiometer
int actuationVolume = analogRead(pot2Pin); // Read the value from the second potentiometer

// Scale the actuation volume so that it falls between the desired volume and the maximum volume
actuationVolume = map(actuationVolume, 0, 1023, desiredVolume, 1023);

// Play the melody
for (int i = 0; i < 25; i++) {
int note = melody[i];
int duration = noteDurations[i];

// Play the note at the desired volume
tone(speakerPin, note, duration * 500 / tempo);
delay(duration * 500 / tempo);

}
}
The speaker plays a bunch of notes really fast and the potentiometers have no effect on the volume. Also, the song is supposed to be Mary Had a Little Lamb.

2

Thanks for the attempt to post code, but... Autoformat the code in the IDE, copy it, click code tags, </>, in this window and paste. Thatmakes it much more readable.

You are not using those readings for anything. Of course they have no effect.

3 
duration * 500 / tempo

And that is 20 milliseconds, so 40ms per note including the delay between notes or 25 notes per second.

tone() doesn't have a volume control. You can put a pot between the Arduino output and the piezo speaker (probably about 1k will work). Ideally it should be an "audio taper" because of the way our ears work. A regular linear pot will be close to full-loudness at the mid-point.

tone() isn't analog and there is no analog output on a regular Arduino. You can adjust the volume by adjusting the duty cycle but you'd have to write your own version of tone() and it's tricky because you have to increase the low-time as you decrease the high-time to keep the frequency the same. And a narrower duty cycle increases harmonics changing the character of the sound. The built-tone() function has a 50% duty cycle for maximum loudness.

4

toneAC() does.
Leo..

5

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