ESP8266 - Potentiometer Piezo Buzzer

This build turns a potentiometer knob into a volume-less switch for a piezo buzzer: turn the knob past a certain point and the buzzer sounds, turn it back and it goes quiet. It is a good first project for reading analog input and driving a digital output on the ESP8266, and a stepping stone toward tone-based alarms or melodies.

The full tutorial, with every detail and the line-by-line code explanation, is on our site: ESP8266 - Potentiometer Piezo Buzzer

What you need

Wiring

The potentiometer's wiper (middle pin) connects to the ESP8266's analog input, A0. The piezo buzzer's signal pin connects to D8, which is configured as a digital output. You can build this on a breadboard or wire it directly, point to point, without one.

How it works

A potentiometer is a variable resistor with three pins; turning the knob changes the voltage at the middle pin, which the ESP8266 reads as an analog value through analogRead(). The piezo buzzer is a simple output device that makes sound when it receives a signal. The sketch compares the potentiometer's analog reading against a fixed threshold: above it, the buzzer pin is driven HIGH and the buzzer sounds; at or below it, the pin goes LOW and the buzzer stays silent.

Code

In setup(), BUZZER_PIN is set to output mode. The loop() function continuously reads the potentiometer's analog value on A0 and checks it against ANALOG_THRESHOLD, which is set to 1000. If the reading exceeds the threshold, digitalWrite() turns the buzzer on; otherwise it turns it off. A variant of this sketch compares a converted voltage value instead of the raw analog reading, and another variant plays a melody once the threshold is crossed, using a separate pitches.h file you create in the Arduino IDE.

esp8266-potentiometer-piezo-buzzer.ino

/* * This ESP8266 NodeMCU code was developed by newbiely.com * * This ESP8266 NodeMCU code is made available for public use without any restriction * * For comprehensive instructions and wiring diagrams, please visit: * https://newbiely.com/tutorials/esp8266/esp8266-potentiometer-piezo-buzzer */ #define POTENTIOMETER_PIN A0 // The ESP8266 pin connected to Potentiometer pin #define BUZZER_PIN D8 // The ESP8266 pin connected to Buzzer's pin #define ANALOG_THRESHOLD 1000 void setup() { pinMode(BUZZER_PIN, OUTPUT); // Configure the ESP8266 pin to the output mode } void loop() { int analog_value = analogRead(POTENTIOMETER_PIN); // read the input on analog pin if (analog_value > ANALOG_THRESHOLD) digitalWrite(BUZZER_PIN, HIGH); // turn on Piezo Buzzer else digitalWrite(BUZZER_PIN, LOW); // turn off Piezo Buzzer }