Just a small and simple project to practice some basics in programming an Arduino Nano V3, to signal how close your can get to an obstacle without touching it. Besides the Arduino Nano, I used an ultrasonic sensor and an infrared sensor module.
Description: The infrared sensor module detects the movement, which will wake up the Nano from sleeping and the ultrasonic sensor starts to meassure the distance between you and the obstacle. According to how far away you are, a different LED is going to flash.
Personal Use: In my case the whole composition is fixed to a wall and it is going to help me to keep the right distance between my car and the wall.