This is an Arduino-based Proximity Sensor circuit wired using the popular HC-SR04 Ultrasonic ranging module,used here for non-contact object detection purpose. The HC-SR04 module includes ultrasonic ...

LED Traffic Lights – Simulates real-world traffic signals. 🔌 Hardware Requirements Arduino Mega 2560 Arduino Nano RFID Module (RC522) with Tags Ultrasonic Sensors (HC-SR04) - 4 or more LEDs (Red, ...

Working Principle • The HC-SR04 ultrasonic sensor sends out an ultrasonic pulse. • The pulse bounces back upon hitting an obstacle. • The sensor calculates the time taken for the pulse to return. • ...