You can read the state of a button using Arduino and a few lines of code. The actual state is shown in the Serial Monitor window as 0 or 1, 0 meaning the button is not pressed and 1 that the button is ...

Example from Arduino playground: ... The Serial Monitor will tell whether the numerical-key inputted to the keypad is correct or not. To activate and deactivate the lock, the user must press * and ...

It is pretty well-known that I’m not a big fan of the Arduino infrastructure. Granted, these days you have more options with the pro IDE and Platform IO, for example. But the original IDE alw… ...