The KY-004 is equipped with a push button that shorts two signal outputs together when the button is pressed.

Operating voltage 3,3 V - 5 V
Environment temperature -25 °C - 105°C
Lifetime 100.000 cycles
Dimensions 18 x 15 x 6 mm

Pin assignment

Code example Arduino

Pin assignment Arduino

Arduino Sensor
Pin 10 Signal
5 V +V
Ground GND
Arduino Sensor
Pin 13 LED+
Ground LED-

This is a sample program that lights up an LED when a signal is detected at the sensor. The modules KY-011, KY-016 or KY-029 can, for example, be used as LEDs, for example.

int Led = 13 ;// declaration of the LED output pin
int Sensor = 10 ;// Declaration of the sensor input pin
int val; // Temporary variable
void setup ()
  pinMode (Led, OUTPUT) ; // Initialize output pin
  pinMode (Sensor, INPUT) ; // Initialize sensor pin
  digitalWrite(Sensor, HIGH) ; // Activate internal pull-up resistor
void loop ()
  val = digitalRead (Sensor) ; // The current signal at the sensor is read out
  if (val == HIGH) // If a signal could be detected, the LED is switched on.
    digitalWrite (Led, LOW);
    digitalWrite (Led, HIGH);

Example program download

Code example Raspberry Pi

Pin assignment Raspberry Pi

Raspberry Pi Sensor
GPIO 24 [Pin 18] Signal
3.3 V [Pin 1] +V
Ground [Pin 6] GND

This is a sample program that prints a console output when as signal is detected at the sensor.

# Import the needed modules and set them up
import RPi.GPIO as GPIO
import time
# Here the input pin is declared, to which the sensor is connected. Additionally the PullUP resistor at the input will be activated
GPIO.setup(GPIO_PIN, GPIO.IN, pull_up_down = GPIO.PUD_UP)
print ("Sensor test [press CTRL+C to exit test]")
# This outputFunction is executed on signal detection
def outputFunction(null):
        print("Signal detected")
# When a signal is detected (falling signal edge) the output function is executed
GPIO.add_event_detect(GPIO_PIN, GPIO.FALLING, callback=outputFunction, bouncetime=100) 
# main program loop
    while True:
# clean up after the program is finished
except KeyboardInterrupt:

Sample program download

To start with the command:

sudo python3

Code example Micro:Bit

Pinout Micro:Bit:

Micro:Bit Sensor
Pin 1 Signal
3 V +V
Ground GND

Sample program download