We learned in the first part of this tutorial how to measure a distance with a HC-SR04 ultrasonic sensor. In this second part, we’ll get rid of the LCD display, and instead show the distance on a custom meter made with LEDs. The idea is to turn colored LEDs ON/OFF depending on how close the car is from the wall.
If you don’t have a reverse backup radar system in your car, or if you park forward in your garage, you probably know this feeling of “am I too close, am I gonna hit the wall??”. Well, in this 2 part tutorial, we’re going to create a simple system to detect how close to the wall your car is.