Adafruit 419 Membrane Matrix Keypad 3×4
Punch in your secret key into this numeric matrix keypad. This keypad has 12 buttons, arranged in a telephone-line 3×4 grid. It's made of a thin, flexible membrane material with an adhesive backing (just remove the paper) so you can attach it to nearly anything. The keys are connected into a matrix, so you only need 7 microcontroller pins (3-columns and 4-rows) to scan through the pad. Check the tutorials tab for links to an Arduino library and example code.
We include a 7-pin extra-long header strip so you can plug this into a breadboard with ease.
We sell this handy kit to convert the signal from the keypad to a simple serial signal reducing the number of required pins to 3
- Weight: 7.5 grams
- Keypad dimensions: 70mm x 77mm x 1mm (2.75" x 3" x 0.035")
- Length of cable + connector: 85mm
- 7-pin 0.1" pitch connector
There is a very nice Matrix Keypad Arduino library that works great with this item. The only thing we suggest is to change the initialization code in the examples to this:
This will swap the * and # keys and also let you connect to the Arduino to match this image