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Matrix Keypad code for use with Raspberry Pi

Project description


I have added support for the BeagleBone Black and would like help testing. If you are able please provide feedback to me at


Python Library for Matrix Keypads. Written and tested on a Model B Raspberry Pi. Supports both a 3x4 and 4x4 keypad included

Current Version:


Project Page:


PyPI page:




Chris Crumpacker





If you are using the Raspberry Pi you will need to install the Python Development Toolkit. First update your package list:

sudo apt-get update

Now install the Dev Kit:

sudo apt-get install python-dev

Then to install Rpi.GPIO itself:

sudo apt-get install python-rpi.gpio

Installing Setuptools next so that you can use PIP is also helpful:

If the I2C Port expander MCP23017 or MCP23008 is being used on a RPi, the Adafruit Python library for I2C and the MCP will need to be installed.

You can clone the whole library like so:

git clone

or the two files needed can be pulled out, &

If using a BeagleBone Black you must install the Adafruit_BBIO. This will give us access to the Adafruit_BBIO.GPIO library that will interface with the pins. Instructions on installing the BBIO library can be found here. The easiest way to install is:

/usr/bin/ntpdate -b -s -u
opkg update && opkg install python-pip python-setuptools
pip install Adafruit_BBIO

For manual installation:

git clone git://
#set the date and time
/usr/bin/ntpdate -b -s -u
#install dependency
opkg update && opkg install python-distutils
cd adafruit-beaglebone-io-python
python install


You can use the source from just downloading the files or Install it as a library via PIP:

pip install matrix_keypad

If using the Adafruit I2C code on a Raspberry Pi, you will need to create links to the Adafruit I2C and MCP230xx code since they are not installed as packages.:

sudo ln -s [path to Adafruit python code]/AdafruitMCP230xx/*.py /usr/local/lib/python2.7/dist-packages/matrix_keypad

Note: you will have to change the part in the brackets and maybe the path to the where the matrix keypad package is

Files Included



See the demo scripts included to see this all in action.

To call the library select which one you intend to use and use the correct line:

from matrix_keypad import MCP230xx


from matrix_keypad import RPi_GPIO


from matrix_keypad import BBb_GPIO

Then initialize and give the library a short name so it is easier to reference later. For the MCP version:

kp = MCP230xx.keypad(address = 0x21, num_gpios = 8, columnCount = 4)

The variables in the keypad function call in this example are the I2C address, then if you are using the MCP23017 or MCP23008 you have to put the number of GPIO pin avaialable (default is 8), Then the “columnCount” is 3 for the 4x3 keypads and 4 for the 4x4 keypads.

For the standard GPIO version you only have to reference the column count and only if you want to change it to the 4x4, it defaults at the 3x4:

kp = RPi_GPIO.keypad(ColumnCount = 4)

It is possible to just check to see if a digit is currently pressed.:

checkKeypad = kp.getKey()

Or a simple function to call the keypad library and loop through it waiting for a digit press

def digit():
    # Loop while waiting for a keypress
    digitPressed = None
    while digitPressed == None:
        digitPressed = kp.getKey()
    return digitPressed

Version History


Initial Scripts


Initial package build


Initial package build and push to PyPI


Updating the to demo selecting the 4x4 keypad


Moved Version Log in README

Updated README Links


Updated References to include the PiLarm code as the inspiration for the “…” code


Updates to the code in both main libs to fix some indenting and other issues from coping the code from blogger to a text file.

Updates to the keypad picking section for the constants to make it actually work


Fixes to more indenting issues. :(


Updated main libs and the demo code.

Added install directions to handle the links to the adafruit code


Updated … and to reflect new package name.

Updated README as well


Updating the README project links

Updating the code’s comments




Beta code added for BeagleBone Black support

Updated the demo code to include examples intializing the BBb_GPIO code

Update all library and demo code with new Comment Header


Updated the BBb library with feedback from testers

Code References

Column and Row scanning adapted from Bandono’s matrixQPI which is wiringPi based.

Support for the BeagleBone Black has been added with the help of Daniel Marcus, Details on his project can be found here; is based on some work that Jeff Highsmith had done in making his PiLarm that was featured on Make.

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