A keypad is one of the most commonly used input devices in microprocessor applications. In a standard keypad wired as an X-Y switch matrix, normally-open switches connect a row to a column when ...

[Andrea] just sent us this great student hack he made for his room. He’s constructed an Arduino keypad door lock — without using any proper fastening hardware! The entire build is made out of scrap ...

Running out of GPIO pins? Learn how to connect multiple buttons to just one Arduino pin using clever wiring and resistor techniques. Perfect for compact projects, keyboards, or when using small boards ...

[J8g8j] has been playing around with an old cellphone. He wanted to control it using a microcontroller but since there’s 24 buttons he wasn’t thrilled about hooking up a couple dozen relays to do the ...