Maker SHED

Punch in your secret key into this numeric matrix keypad. This keypad has 12 buttons, arranged in a telephone-line 3x4 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 how-to 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.

• 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:

• #include 

• const byte ROWS = 4; //four rows
• const byte COLS = 3; //three columns
• char keys[ROWS][COLS] = {
• {'1','2','3'},
• {'4','5','6'},
• {'7','8','9'},
• {'*','0','#'}
• };
• byte rowPins[ROWS] = {8, 7, 6, 5}; //connect to the row pinouts of the keypad
• byte colPins[COLS] = {4, 3, 2}; //connect to the column pinouts of the keypad
• Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );
• This will swap the * and # keys and also let you connect to the Arduino to match this image