Punch in your secret key (or Jenny's number) into this numeric matrix keypad. This keypad has 16 buttons, arranged in a telephone-line 4x4 grid. The keys are connected into a matrix, so you only need 8 microcontroller pins...

Hey, Jenny, I've got your number! And I'm going to dial 867-5309 into this very nice phone-style matrix keypad. This keypad has 12 buttons, arranged in a telephone-line 3x4 grid. It's made of plastic with sturdy plastic buttons. The keys are connected to a matrix so you only need 7...

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...

Punch in your secret key into this numeric membrane keypad. This keypad has 4 buttons, and since every key has its own wire line, no matrix code is required - just treat these like every day switches. The membrane is soft and has a removable paper backing to expose a strong adhesive so you can...