The KY-010 Photo Interrupter module is a switch that will trigger a signal when light between the sensor’s gap is blocked.
This module is suitable for various electronics platforms like Arduino, Raspberry Pi, ESP32 and others.


KY-010 Specifications
This module consists of an optical emitter/detector and 3 male header pins on the front. On the back there are two resistors of 1kΩ and 33Ω.
The sensor uses a beam of light between the emitter and detector to check if the path between both is being blocked by an opaque object.
Operating Voltage | 3.3V ~ 5V |
Board Dimensions | 18.5mm x 15mm [0.728in x 0.591in] |
Connection Diagram
Connect the power line (middle) and ground (left) to +5V and GND respectively. Connect signal (S) to pin 3 on the Arduino.
KY-010 | Arduino |
---|---|
– (left) | GND |
middle | +5V |
S (right) | Pin 3 |

KY-010 Arduino Code
The following sketch will light up the LED (pin 13) on the Arduino when there’s an object blocking the path between the sensor’s gap.
int Led = 13; // define LED pin
int buttonpin = 3; // define photo interrupter signal pin
int val; //define a numeric variable
void setup()
{
pinMode(Led, OUTPUT); // LED pin as output
pinMode(buttonpin, INPUT); //photo interrupter pin as input
}
void loop()
{
val=digitalRead(buttonpin); //read the value of the sensor
if(val == HIGH) // turn on LED when sensor is blocked
{
digitalWrite(Led,HIGH);
}
else
{
digitalWrite(Led,LOW);
}
}
HI, what’s the wave lengh of the Diode please ?