Python Code for 3×4 Matrix Keypad with Raspberry Pi #piday #raspberrypi @Raspberry_Pi

membranekeypad34arduino_LRG

Chris Crumpacker writes:

Another module of my alarm interface is done. I picked up a 3×4 matrix keypad from Adafruit (http://www.adafruit.com/products/419) But couldn’t find any good python code examples for it’s use. I was able to find a few examples that lead me down the right path in terms of scanning rows first as inputs and then swaping pins to scan the columns. I wrote two libraries, the first just uses 7 of the Raspberry Pi’s GPIO pins then I also wrote one that works for the MCP23008 chip since I’m really in a mode of saving pins when I can 🙂 Then also just wrote a demo script to show calling the libraries and their use.

Here is the code as it stands now, I have some ideas on how to change it to be better but this is fully working for now.

Check out the blog post with source code here!


Featured Adafruit Products

membranekeypad34_MED

Membrane 3×4 Matrix Keypad + extras – 3×4 – Punch in your secret key into this numeric matrix keypad. This keypad has 12 buttons, arranged in a telephone-line 3×4 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. (read more)


998Each Friday is PiDay here at Adafruit, be sure to check out our posts, tutorials and new Raspberry Pi related products. Have you tried the new “Adafruit Raspberry Pi Educational Linux Distro”? It’s our tweaked distribution for teaching electronics using the Raspberry Pi. But wait, there’s more! Try our new Raspberry Pi WebIDE! The easiest way to learn programming on a Raspberry Pi.

We now have Raspberry Pi Model B with 512MB RAM in stock and shipping now!


Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7:30pm ET! To join, head over to YouTube and check out the show’s live chat and our Discord!

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Join over 38,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython – The easiest way to program microcontrollers – CircuitPython.org


New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — New Products 11/15/2024 Featuring Adafruit bq25185 USB / DC / Solar Charger with 3.3V Buck Board! (Video)

Python for Microcontrollers – Adafruit Daily — Python on Microcontrollers Newsletter: A New Arduino MicroPython Package Manager, How-Tos and Much More! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi

EYE on NPI – Adafruit Daily — EYE on NPI Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

Adafruit IoT Monthly — The 2024 Recap Issue!

Maker Business – Adafruit Daily — Apple to build another chip at TSMC Arizona

Electronics – Adafruit Daily — SMT Tip – Stop moving around!

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !


No Comments

No comments yet.

Sorry, the comment form is closed at this time.