This work presents the design, construction and testing of a motion detection system. The principle of operation of this burglar alarm is simple. When an object moves towards the direction of the sensor the alarm is triggered and the siren begins to operate. The sensor can operate in a dark environment as it depends on the temperature of an object, the system also supports lighting of your environment as you can on and off your bulbs through the system. These actions alert the owner of the house and security staff to the presence of an intruder. This project was developed to make a motion detector using the Arduino microcontroller and the PIR sensor. The other items used in this project are the LED and a Piezo buzzer for signaling once motion is detected. The group aimed to show how each component functions and how they work together to perform the task. They also constructed a circuit from which the components were connected. From the results, it is evident that motion, a physical property, can be used to effect changes in a digital device and using the LED and Piezo buzzer, the motion can be announced thereby allowing it to be used as an intruder alarm.