Ever tear open a potentiometer? If you haven’t, you can still probably guess what’s inside. A streak of resistive material with some kind of contact that moves across it as you rotate the shaft, right ...

I purchased one of each of these cheap sensors recently from aliexpress for testing purposes. Compared with the ubiquitous HC-SR04 (*), I liked the idea of having a combined emitter/receiver, i.e.

Arduino library for the I2C LCD display, typical 20x4 characters. The library is inspired by the excellent New-LiquidCrystal library by F. Malpartida. Therefore the interface is kept quite identical, ...