### Project 11: Photo interrupter module

![](media/wps3.png)

**1.Introduction**
Upright part of this sensor is an infrared emitter and on the other side, it’s a shielded infrared detector. By emitting a beam of infrared light from one end to other end, the sensor can detect an object when it passes through the beam. It is used for many applications including optical limit switches, pellet dispensing, general object detection, etc.

**2.Hardware required**

- Supply Voltage: 3.3V to 5V
- Interface: Digital
- Size: 30*20mm
- Weight: 3g

**3.Connection Diagram**

![](media/wps4-1764323312062-5.jpg)

**4.Sample program**

```c
int Led = 13 ;// define LED Interface
int buttonpin = 3; // define the photo interrupter sensor interface
int val ;// define numeric variables val

void setup ()
{
  pinMode (Led, OUTPUT) ;// define LED as output interface
  pinMode (buttonpin, INPUT) ;// define the photo interrupter sensor output interface   
}

void loop ()
{
  val = digitalRead (buttonpin) ;// digital interface will be assigned a value of 3 to read val
  if (val == HIGH) // When the light sensor detects a signal is interrupted, LED flashes
  {
    digitalWrite (Led, HIGH);
  }
  else
  {
    digitalWrite (Led, LOW);
  }
}
```