For this assignment I had a very similar idea to Maimuna’s post about a car sensor which is usually what comes to mind when thinking of using an ultrasonic sensor. My project is also a car sensor, I just added more LED’s to fit my narrative of a warning meter which should go from “On” to red , to orange, then red proximity (in 2 intervals = 2 LED’s for each color).
I decided to use two LEDs for each level to indicate the different values that represent proximity which go from around 4- 4o, until the range is out of the ultrasonic sensor. Essentially, the last red LED will light up at around an output of 5, which means the car will hit the wall/object or is dangerously close to it.
I only used 1 white LED because it is only there to indicate that the car is within the range of the sensor to begin determining proximity.
One Issue that I had while working on this would be the LED’s. The first time I hooked everything up the LED’s were noticeably dim, this was not due to the resistors (I used 270 Ohms) but the LED’s themselves. I ended up switching out the LEDs I grabbed from the lab with the ones we had in the box which worked much more brighter as they have a voltage drop of 2.0-2.4v (unlike the ones in the lab, (I still don’t know their voltage drop).
For my demo, I just made a car from a food box and some tires I just taped to the sides.