Metal touch sensor

By Admin, 15/09/2026 · 4 min read

Metal touch sensor guide for the 37-in-1 Arduino Sensors Kit.

37-in-1 kit, module 33

KY-036: Metal touch sensor

Reacts when a finger touches the bare metal leg. Plug it in, upload the sketch, then change the thing it senses and watch the reading.

All 37 modules Nano and shield wiring Joy-IT page for this module

KY-036, Metal touch sensor

Reacts when a finger touches the bare metal leg.

How it works

Metal touch sensor

What is going on

The exposed transistor leg picks up the tiny mains hum your body carries, and the transistor amplifies it. The analog pin shows the level, the digital pin trips above the potentiometer setting. It is a touch switch, and it works better on a laptop that is plugged in than on battery, because the hum is stronger.

Connections

Wiring to the Arduino Nano on its expansion shield

The pins below match the sketch further down this page; change one and change the other.

Power off first

Unplug the USB cable before you plug in, move or remove any module.

A lead plugged in live can touch the wrong pin for a moment, and 5 V on a signal pin is how a module dies. Unplug, wire, check the letters, then plug the cable back in.

Module pinGoes to

Module A0S row of the column marked A0, analog bank

Module D0S row of the column marked 3, digital bank

Module +VV row, 5 V

Module GNDG row, ground

Where it plugs in on the shield

The ringed column is the one this module uses. G on top for ground, V in the middle for 5 V, S at the bottom for the signal. A module with more than one signal wire uses one column per wire.

Read the letters on the shield

Both banks on this shield read G, V, S from the top. The letters are printed at the ends of the rows.

The module's minus or GND pin goes to G, its plus or VCC pin to V, and each signal to the S row of the numbered column.

A module in backwards puts 5 V on the signal pin. Some survive it, plenty do not.

Starter sketch

Code you can copy and upload

Every sketch on these pages is compiled for the Arduino Nano before it is published. The pin numbers at the top match the connection table above.

ky036.inoArduino C++

1const uint8_t RAW = A0, TOUCHED = 3;
2const uint8_t LED = 13;
3
4void setup() {
5  pinMode(TOUCHED, INPUT);
6  pinMode(LED, OUTPUT);
7  Serial.begin(9600);
8}
9
10void loop() {
11  bool touch = digitalRead(TOUCHED) == HIGH;
12  digitalWrite(LED, touch ? HIGH : LOW);
13  Serial.print("raw:");
14  Serial.print(analogRead(RAW));
15  Serial.print(",touch:");
16  Serial.println(touch ? 1 : 0);
17  delay(100);
18}

Try first

Touch the metal leg. Then touch it while holding the laptop's metal case with the other hand.

The quickest way to see it respond.

1

Unplug the USB cable. Plug the module into the column shown above, minus to G, plus to V, signal to S.

2

Plug the USB cable back in. Copy the sketch, upload it, and open Tools > Serial Monitor at 9600 baud.

3

Do the thing the module senses and watch the reading, the L LED, or the sound respond.

Reference

More on this module

The Joy-IT page has the datasheet figures and examples for other boards; the repository has the original vendor files.

Joy-IT SensorKit: KY-036
KY-numbered kit repository: datasheets and original examples
Arduino Nano and I/O expansion shield wiring
Arduino Nano and DHT11 electronics workshop
All 37 modules

Survey and feedback

Help improve MakerAccess

Have an idea for what MakerAccess should stock, improve, or explain next? Share it in the survey. If you bought or used a product and want to comment on the item itself, use the product feedback form.

Do the survey Product feedback form

Metal touch sensor

KY-036: Metal touch sensor

KY-036, Metal touch sensor

Metal touch sensor

What is going on

Wiring to the Arduino Nano on its expansion shield

Where it plugs in on the shield

Read the letters on the shield

Code you can copy and upload

Touch the metal leg. Then touch it while holding the laptop's metal case with the other hand.

More on this module

Help improve MakerAccess

Related articles