Bi-Directional People Counter Using PIR Sensors and Arduino UNO

The Bi-Directional People Counter is a simple system that counts the number of people entering and exiting a room using two PIR motion sensors. The setup uses an Arduino UNO to detect the sequence in which the PIR sensors are triggered. If Sensor 1 activates first followed by Sensor 2, the system identifies it as a person entering. If Sensor 2 activates first followed by Sensor 1, it detects a person leaving. The count of people inside the room is updated accordingly.

A 16×2 LCD display (non-I2C) is used to show the number of people currently inside. The LCD is connected in 4-bit mode and continuously displays “People In Room:” along with the live count. This system is useful for classrooms, labs, shops, and any place where entry/exit monitoring is required.

The circuit is simple and includes two PIR sensors placed at the entrance, the Arduino for processing, and the LCD for real-time display. The system provides an automatic, hands-free way to monitor occupancy with minimal components and easy installation.