ESP32 - Touch Sensor

This tutorial instructs you how to use ESP32 with the touch sensor (also known as touch switch, or touch button).

Hardware Used In This Tutorial

1	×	ESP-WROOM-32 Dev Module
1	×	USB Cable Type-C
1	×	Touch Sensor
1	×	Breadboard
1	×	Jumper Wires
1	×	(Optional) DC Power Jack
1	×	(Recommended) ESP32 Screw Terminal Adapter

Or you can buy the following sensor kit:

DIYables Sensor Kit 30 types, 69 units

Disclosure: some of these links are affiliate links. We may earn a commission on your purchase at no extra cost to you. We appreciate it.

Introduction to Touch Sensor

Touch Sensor Pinout

Touch sensor has 3 pins:

GND pin: connect this pin to GND (0V)
VCC pin: connect this pin to VCC (5V or 3.3v)
SIGNAL pin: is an output pin: LOW when NOT touched, HIGH when touched. This pin needs to be connected to ESP32's input pin.

How Touch Sensor Works

The state of the SIGNAL pin is LOW when the touch sensor is NOT touched
The state of the SIGNAL pin is HIGH when the touch sensor is touched

ESP32 - Touch Sensor

We can connect the touch sensor's SIGNAL pin to an ESP32's input pin and use the ESP32 code to read the state of touch sensor.

Wiring Diagram between Touch Sensor and ESP32

This image is created using Fritzing. Click to enlarge image

If you're unfamiliar with how to supply power to the ESP32 and other components, you can find guidance in the following tutorial: How to Power ESP32.

How To Program Touch Sensor

Initializes the ESP32 pin to the digital input mode by using pinMode() function. For example, pin GPIO18

pinMode(18, INPUT_PULLUP);

Reads the state of the ESP32 pin by using digitalRead() function.

int inputState = digitalRead(18);

Touch Sensor - ESP32 Code

The below code reads the state of the touch sensor and print it to the Serial Monitor.

/* * This ESP32 code is created by esp32io.com * * This ESP32 code is released in the public domain * * For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-touch-sensor */ #define SENSOR_PIN 18 // ESP32 pin GPIO18 connected to the sensor's SIGNAL pin of touch sensor void setup() { // initialize serial communication at 9600 bits per second: Serial.begin(9600); // initialize the ESP32's pin as aninput pinMode(SENSOR_PIN, INPUT); } void loop() { // read the state of the the input pin: int state = digitalRead(SENSOR_PIN); // print state to Serial Monitor Serial.println(state); }

Quick Instructions

If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE.
Copy the above code and paste it to Arduino IDE.
Compile and upload code to ESP32 board by clicking Upload button on Arduino IDE
Touch your finger to the sensor and release.
See the result on Serial Monitor. It looks like the below:

COM6

Send

0 0 0 1 1 1 1 1 1 0 0

Autoscroll Show timestamp

Clear output

9600 baud

Newline

How to detect the state change from LOW to HIGH

/* * This ESP32 code is created by esp32io.com * * This ESP32 code is released in the public domain * * For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-touch-sensor */ #define SENSOR_PIN 18 // ESP32 pin GPIO18 connected to the sensor's SIGNAL pin of touch sensor // Variables will change: int lastState = LOW; // the previous state from the input pin int currentState; // the current reading from the input pin void setup() { // initialize serial communication at 9600 bits per second: Serial.begin(9600); // initialize the ESP32's pin as aninput pinMode(SENSOR_PIN, INPUT); } void loop() { // read the state of the the input pin: currentState = digitalRead(SENSOR_PIN); if (lastState == LOW && currentState == HIGH) Serial.println("The sensor is touched"); // save the the last state lastState = currentState; }

Video Tutorial

Making video is a time-consuming work. If the video tutorial is necessary for your learning, please let us know by subscribing to our YouTube channel , If the demand for video is high, we will make the video tutorial.

Language References

Learn More

※ OUR MESSAGES

As freelancers, We are AVAILABLE for HIRE. See how to outsource your project to us
If this tutorial is useful for you, please support us to make more tutorials.
Please feel free to share the link of this tutorial. However, Please do not use our content on any other websites. We invested a lot of effort and time to create the content, please respect our work!