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ESP32 - Servo Motor controlled by Potentiometer

In a previous tutorial, We have learned how a potentiometer triggers a servo motor. In this tutorial, We are going to learn how to rotate a servo motor according to the potentiometer's output value

Hardware Required

1	×	ESP-WROOM-32 Dev Module
1	×	Micro USB Cable
1	×	Servo Motor
1	×	Potentiometer
1	×	Breadboard
6	×	Jumper Wires

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About Servo Motor and Potentiometer

If you do not have knowledge of servo motor and potentiometer (pinout, how they work, how to connect them to ESP32, how to program for them...), learn about them in the following tutorials:

Wiring Diagram

Image is developed using Fritzing. Click to enlarge image

How To Program

Reads the value of the potentiometer (value between 0 and 1023)

int analogValue = analogRead(A0);

Scales it to angle (value between 0 and 180)

int angle = map(analogValue, 0, 1023, 0, 180);

Sets the servo position according to the angle

myServo.write(angle);

ESP32 Code

/* * Created by esp32io.com * * This example code is in the public domain * * Tutorial page: https://esp32io.com/tutorials/esp32-servo-motor-controlled-by-potentiometer */ #include <Servo.h> Servo myServo; // create servo object to control a servo void setup() { // initialize serial communication at 9600 bits per second: Serial.begin(9600); myServo.attach(9); // attaches the servo on pin 9 to the servo object } void loop() { // reads the value of the potentiometer (value between 0 and 1023) int analogValue = analogRead(A0); // scales it to use it with the servo (value between 0 and 180) int angle = map(analogValue, 0, 1023, 0, 180); // sets the servo position according to the scaled value myServo.write(angle); // print out the value Serial.print("Analog: "); Serial.print(analogValue); Serial.print(", Angle: "); Serial.println(angle); delay(100); }

Quick Steps

If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE
Connect the ESP32 board to your PC via a micro USB cable
Open Arduino IDE, select the right ESP32 board and COM port
Copy the above code and paste it to Arduino IDE
Click Upload button on Arduino IDE to compile and upload code to ESP32 board

Open Serial Monitor on Arduino IDE

How to open serial monitor on Arduino IDE

Rotate the potentiometer
See the servo motor's rotation
See the result on Serial Monitor. It looks like the below:

COM6

Send

Analog: 0, Angle: 0 Analog: 85, Angle: 14 Analog: 201, Angle: 35 Analog: 286, Angle: 50 Analog: 370, Angle: 65 Analog: 444, Angle: 78 Analog: 521, Angle: 91 Analog: 608, Angle: 106 Analog: 690, Angle: 121 Analog: 793, Angle: 139 Analog: 907, Angle: 159 Analog: 1023, Angle: 180 Analog: 1023, Angle: 180

Autoscroll Show timestamp

Clear output

9600 baud

Newline

Code Explanation

Read the line-by-line explanation in comment lines of source code!

Video Tutorial

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Alternative Servo Motors

The above code also works with the following servo motors:

MG996R - Metal Gear Torque Servo Motor for high weight application
SG90 Micro Servo Motor for low weight application
And other standard servo motors

Alternative Potentiometers

The above code also works with the following rotary angle sensors:

Servo Motor on Commercial Products

Potentiometer on Commercial Products

Digital Oscilloscope