Tag archives for PIR
Microcontrollers have become very useful in embedded design as they can easily communicate with other devices, such as sensors, switches, displays, keypads, motors and even other microcontrollers. A microcontroller is basically used as the brain or intelligent processing unit to control other devices connected (interfaced) to it in embedded systems just like a PLC is in industrial automation. Interfacing a device with a microcontroller in simplest terms simply means to connect a device to a microcontroller. This article will make it easier to anybody with very limited experience in electronics to learn how to interface different sensors widely with a PIC Microcontroller.
In this project, when a motion sensor (PIR) detects a movement of an intruder, an SMS will be sent to a predefined number which could be you or your security reaction company and if it is not disarmed within 30 seconds, a relay will be triggered to switch ON the siren or any other sound device. When the device is turned on, it needs to be armed by pressing the push button then it will give you one minute to allow you to safely exit your home or sleep without triggering the alarm. After that, the program enters the alarm mode, the program will constantly monitors the input from the PIR. When motion is detected, the device will send an SMS message to a predefined phone number stating: "Alarm!! Intruder Detected in your House!!! Siren will be activated in few seconds.".