4 x 4 Matrix Keypad
Membrane keypads are an excellent starting point for adding key input to a project because they are inexpensive, long-lasting, and resistant to water. And knowing how to interface them with an Arduino is extremely useful for building a variety of projects that require user input for menu selection, password entry, or robot operation.
Graphic Overlay – Graphic overlays are typically made of polyester because it has better flex life than polycarbonate.
Metal Domes – This layer houses metal domes or polydomes that provide tactile feedback.
Top Circuit Layer – This is typically a polyester printed layer with silver-filled electrically conductive inks. This layer terminates as a flexible tail that connects to the outside world.
Spacer – This layer separates the top and bottom circuits, allowing the switch to remain normally open until the keypad is pressed.
Bottom Circuit Layer – This is typically a polyester printed layer with silver-filled electrically conductive inks. This layer also terminates as a flexible tail.
Rear Adhesive Layer – This layer sticks the keypad to almost anything, which is convenient.
- Contact resistance of 500 (Ω)
- Insulation resistance 100M (Ω)
- Key Operating Force 150-200N
- Rebound time 1 (ms)
- Life of 100 million (times)
- Operating Temperature 60 (℃)
- Circuit Rating: 35V (DC), 100mA, 1W
- Contact resistance: 10Ω ~ 500Ω
- Insulation resistance: 100MΩ 100V
- Dielectric Strength: 250VRms (50 ~ 60Hz 1min)
- Electric shock jitter: <5ms