Difficulty Level = 9 [What’s this?] This was a fun project I built using a perf-board Arduino with GPS receiver, some LEDs, some long wire, some clever code, and a car! I have this friend that has a speeding problem. So I built this device for my friend so...
Difficulty Level = 1 [What’s this?] Most keypads like this are wired so it makes it straightforward to figure out what button is being pressed. With 3 columns and 4 rows of buttons, you only need 7 wires. Typically all the buttons in a column are connected...