The 2x2 Key Switch Click Board™ has a 4 button keypad. The Click Board™ 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 Board™ is designed to use either a 3.3V or 5V power supply. The buttons can be independently read.