CAT# KP-12
$4.95 each
12 key keypad with numerals 0 -9, * and #. One common terminal. Contacts rated 20 mA @ 24 Vdc. 2.01" x 2.24". Black with white buttons. Mounting holes on 1.8" x 2.24" centers. Can be rear-mounted through a 2.25" X 1.81" cutout.
Average Customer Review:  (7 Reviews) Write A Review

Customer Comments

Average Customer Review:  (7 Reviews) Write A Review

A customer from Atlanta, GA
If you have an analog to digital
converter pin available, try this.
Connect the common pin to a 1k ohm resistor which is connected to +5 volts. Connect each pin to a different value resistor, for instance connect 0 to 100 ohms, 1 to 220 ohms, 2 to 330 ohms, etc. Now connect your adc input pin to the common (junction of the 1k resistor and the common of the keypad).
When you are not pressing anything the adc will read full voltage, When you press the zero key, it will read 0.45 volts, when you press the 1 it will read 0.83 volts, etc. Of course you'll have to translate the value from the adc pin to voltage based on the resolution of the adc.
So for the price of 12 resistors you only need to read one pin.

A customer from NEW YORK CITY
There is only one terminal for power (Pin 1) and 12 pins for output. You cannot do row column scanning as is needed to Matrix encoding. You need to wire all twelve outut pins individually. THe KP-22 is said be matrix-encoded.

A customer from I am working as an GA in ULL
i need a pin description for 12 key keypad with 8 terminals
I am not able to figure out the pin configuration of 12 key, key pad with 8 terminals. i think it should me matrix encoded.

A customer from San Francisco, CA US
"Matrix encoded" details.
I'm quite satisfied with the quality and function. It's new in package, no problems at all, but this wasn't designed to work with, say, the EDE1144 KeyPad Encoder IC. This keypad has one common pin and one output in for each key. Grouped by column, the pins are (pin=[key]): 1=Common, 2=N/A, 3=[*], 4=[7], 5=[4], 6=[1], 7=[0], 8=[8], 9=[5], 10=[2], 11=[#], 12=[9], 13=[6], 14=[3]

A customer from NY
Great for use with LS7220 Digital Lock chip
Perfect keypad for input to the LS7220 lock chip, which requires unencoded lock inputs. Small size for easy mounting-
Non clicking but no problem with fast entry of code. -

Datasheet for digital lock IC: