2x2 Key click has a 4 button keypad. The click allows multiple key presses and has a debounce circuit composed of 74HC32 quad 2-input OR gate from NXP and the SN74HC14 Hex Schmitt-Trigger Inverter from Texas Instruments. 2x2 Key click is designed to use either 3.3V or 5V power supply. The buttons can be independently read.
