keypad for Arduino is a physical device that allows you to input data, typically numbers or characters, through a set of buttons. It consists of a grid of buttons arranged in rows and columns, and each button corresponds to a unique combination of row and column pins on the Arduino board.
You can connect the keypad to the Arduino to allow user interaction, such as entering PIN codes, controlling devices, or navigating menus. Keypads come in different sizes, commonly 3x4 (3 rows, 4 columns) or 4x4 (4 rows, 4 columns).
4x4 matrix keyboard:
Contact resistance: 500
Insulation resistance:100M
Key Operating Force 150-200N
Life of 100 million (times)
Circuit Rating: 35V (DC), 100mA, 1W
Contact Resistance: 10 ~ 500
Insulation Resistance: 100M 100V
Dielectric Strength: 250VRms (50 ~ 60Hz 1min)
Electric Shock jitter: <5ms
Life Span: tactile type: one million times
Operating Pressure: Touch feeling: 170 ~ 397g (6 ~ 14oz)
Switch Travel: touch-type: 0.6 ~ 1.5mm
Operating temperature: -40 to +80
Storage temperature: -40 to +80
Temperature: from 40,90% to 95%, 240 hours
