Arduino Challenge for Using Potentiometer to Tune the Piezo

Johnny Chen
2 min readMay 21, 2023

Arduino Starter Kit Project 06 Youtube Video Challenge

In the Arduino tutorial for starter kit (https://www.youtube.com/watch?v=DnD92Q_Kpac), the challenge presented for changing the phototransistor to control the Piezo to potentiometer.

First, the terms for the project explained:

  • Potentiometer: It is used to control the voltage or current in a circuit. The potentiometer consists of a resistive track and a sliding contact, which can be moved by rotating a knob or shaft. The two pins are connected to voltage and ground, while the other would connect to analog signal input to Arduino.
  • Piezo: A piezo is a device that vibrates when receiving electricity, and would create song wave.

So the challenge would involve adjusting project 5: Mood Cue and project 6: Light Theremin.

// declare
int sensorValue; // hold sensor value
int potLow = 1023; // calibrate low value
int potHigh = 0; // calibrate high value
const int ledPin = 13; // LED pin

void setup() {
// Initialize Serial Monitor
Serial.begin(115200);

// Make the LED pin an output and turn it on
pinMode(ledPin, OUTPUT);
digitalWrite(ledPin, HIGH);

// calibrate for the first five seconds after program runs
while (millis() < 5000) {
sensorValue = analogRead(A0);
// record the max sensor value
if (sensorValue > potHigh) {
potHigh = sensorValue;
}
// record the min sensor value
if (sensorValue < potLow) {
potLow = sensorValue;
}
}
// turn the LED off, signaling the end of the calibration period
digitalWrite(ledPin, LOW);
}

void loop() {
// read analog signal to A0 pin
sensorValue = analogRead(A0);
// map the sensor values to a wide range of pitches
int pitch = map(sensorValue, potLow, potHigh, 100, 2000);

// play the tone for 20 ms on pin 8
tone(8, pitch, 20);

Serial.print("sensorVal: " + String(sensorValue));

int angle = map(sensorValue, potLow, potHigh, 0, 179);
Serial.println("Angle: " + String(angle));

delay(10);
}

The schematic of the Arduino would be pretty similar to project 06, except for replacing phototransistor with potentiometer. Also, we could put capacitor in-between potentiometer and wires-to-voltage-and-ground for smoothing out the voltage changes.

Thank you for your reading, please leave a comment!

Ref:

  1. ARDUINO PROJECT BOOK
  2. 05 Starter Kit: Mood Cue (https://www.youtube.com/watch?v=ybG6TLamn_I&t=3s)
  3. 06 Starter Kit: Theremin (https://www.youtube.com/watch?v=DnD92Q_Kpac)

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