This is a highly integrated module popularly used for entry detection, it can be easily adopted in any system. Power it up and wait 1-2 seconds for the sensor to get a snapshot of the still room. If anything moves after that period, the ‘alarm’ pin will go low. This sensor checks for infrared heat in it’s detecting angle. Human body, pets and several other things emit energy that the sensor is looking for, it compares with the snapshot and if there is a recent change it triggers.
Get on with your Home alarm security audit gear and experiment with this sensor to get a better understanding about its efficiency and working method. Infrared motion detectors are common all around the world for many different appliances. It’s great for a project that requires automated motion feedback. Commonly found on automatic trigger light systems, where lights are ON when someone is in range and OFF when no one is around. Save power or trigger other actuators like a door opener or pet feeder.
There are two adjustable potentiometer on the module, you can use them to change the trigger sensitivity and the duration of the trigger signal. Besides, the module can also be set as retriggerable or un- retriggerable. When the switch is in the H position, the module is retriggerable and is unretrigerred when the switch is in L position.
References
Specification
- Input Voltage: DC 4.5-20V
- Static current: 50uA
- Output signal: 0,3V or 5V (Output high when motion detected)
- Sentry Angle: 110 degree
- Sentry Distance: max 7 m
- Shunt for setting overide trigger: H – Yes, L – No
Hardware
Connect this sensor to your Arduino digital pins( D2 for example). Adjust the RT&CDS to change trigger sensitivity and duration of the trigger signal.Set the module as retriggerable or un- retriggerable with the switch, when the H position, the module is retriggerable and is unretrigerred when the switch is in L position.
Power up the PIR module, and connect the “sig” to D2, program you Arduino as below:
const int ledPin=13;//The led to indicate the motion void setup(){ Serial.begin(9600); pinMode(2, INPUT);//Use pin 2 to receive the signal outputted by the module pinMode(ledPin, OUTPUT); } void loop() { int sensorValue = digitalRead(2); if(sensorValue==1) digitalWrite(ledPin,HIGH); else digitalWrite(ledPin,LOW); Serial.println(sensorValue, DEC); //Print the state of the signal through the serial monitor. }
When someone moves before the sensor, the led on the arduino board light and “1” is printed on the serial monitor.