Keypad phones, believe it or not, are still in use, and there is a surprising amount of variety to choose from. Some of the phones include 4G connectivity, cameras, and are built to last. If you're ...

This is the master device that polls a keypad to check for a keypress. The keypress is sent over I2C. One slave HCS08 is connected to an LED bar that displays patterns based on the keypress and the ...