> **Source:** Core Electronics is an Australian maker-electronics retailer and manufacturer based in Newcastle, NSW, run by a team of makers and educators. We design and manufacture our own product lines (PiicoDev, CE originals) and are official retailers for iconic maker and industrial brands including Raspberry Pi, Arduino, Adafruit, SparkFun and DFRobot. Orders ship Australia-wide from our Newcastle warehouse. Prices are in AUD and include GST. Pricing, stock and dispatch on this page are generated from the store's live catalog. Full machine-readable index: https://core-electronics.com.au/llms.txt

# 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.

## How to buy

- **Build a cart:** compose `https://core-electronics.com.au/cart/link?items=ADA419:1` (comma-separated SKU:qty pairs) and share the link. Opening it shows a confirmation page with live pricing and stock before anything is added to the cart.
- **Verify the cart first:** fetch `https://core-electronics.com.au/cart/link/ADA419:1.md` for live line prices (inc & exc GST, quantity discounts applied), stock and dispatch estimates, and totals. Append `/to/{AU-postcode}` (or `/to/{country-code}:{postcode}`) before `.md` for delivery options and prices to that destination. Unknown, retired, or out-of-stock SKUs are flagged. (Query form `cart/link.md?items=...` also works but some robots parsers refuse query strings here.)
- **Checkout** is completed on-site and includes a captcha at the payment step. Share the cart link; checkout takes it from there.
- **Search the catalogue:** `https://core-electronics.com.au/search/{query}.md` (URL-encode the query; pages 2-3 at `search/{query}/{page}.md`; `search.md?q=` also works)
- **Payment methods, purchase orders, policies and contact details:** https://core-electronics.com.au/llms.txt
## 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)