12key Membrane keypad 4*3 matrix
Punch in your secret key into this numeric matrix keypad. This keypad has 12 buttons, arranged in a telephone-line 3x4 grid. 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 some header so you can plug this into a breadboard with ease, some light soldering is required to attach it. Or you can use plain wires if you like.
There's a great Matrix Keypad Arduino library that should work great with this item with minor adjustments. Note that the rows and columns are intermixed. The order from left to right is COL2, ROW1, COL1, ROW4, COL3, ROW2, ROW1