# Membrane 3x4 Matrix Keypad + extras - 3x4

**Type:** Product page · **SKU:** ADA419 · **Brand:** [Adafruit](https://core-electronics.com.au/brands/adafruit-australia)
**Page:** https://core-electronics.com.au/membrane-3x4-matrix-keypad-3x4.html ([markdown](https://core-electronics.com.au/membrane-3x4-matrix-keypad-3x4.html.md))

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...

## Pricing

- **Price:** $8.05 (inc GST) — $7.32 AUD, exc GST
- **Quantity discounts:** 10+ $7.10 (exc GST) · 50+ $6.95 (exc GST)

## Availability & dispatch

- In stock, ships same business day if ordered before 2PM (Australia/Sydney).
- We can dispatch 1 today, and up to 500 more in 8–12 days.

## Description

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 tutorials tab for links to an Arduino library and example code.
 
 Adafruit include a 7-pin extra-long header strip so you can plug this into a breadboard with ease.

## Technical Details

- 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:

 ```
#include "Arduino.h" #include "Keypad.h" 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](https://core-electronics.com.au/attachments/localcontent/membranekeypad34arduino_LRG_12567f2a1ef.jpg)

 ![](https://core-electronics.com.au/attachments/localcontent/rohs_icon_8216055e11.jpg)

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/4/1/419-05.jpg)