We will make a simple security device that will sense unusual motion in your home. Say, if anyone enters your room, the motion sensor will detect the human presence and make sound. We will also connect an LED too. You can later connect a GSM module to either call or send you an SMS if anyone enters your room. This time we will use the following components to build our motion detecting home security device:
PIR (Passive InfraRed) motion sensor
Buzzer or Speaker
LED
Resistors
Jumper Wires
Arduino
The following image shows a PIR sensor:
It has three pins, VCC or +DC voltage, GND, and Output or Data. The connection between the Arduino and the PIR is simple. We will connect the VCC to the 5V pin of the Arduino with the jumper wire, GND to the GND of the Arduino, and the Data pin will be connected to any of the digital pins. In my case it is digital pin 2. See the following figure for clarification. We will connect the speaker's anode to Arduino digital pin 3 and the LED's positive pin...