An interrupt-based Python 2/3 library for reading matrix keypad key presses using Raspberry Pi GPIO pins.
pip install pad4pi
Tested on a Raspberry Pi B+ using a 4x3 matrix keypad but it should work with 4x4 and other sizes.
from pad4pi import rpi_gpio
KEYPAD = [
[1, 2, 3],
[4, 5, 6],
[7, 8, 9],
["*", 0, "#"]
]
ROW_PINS = [4, 14, 15, 17] # BCM numbering
COL_PINS = [18, 27, 22] # BCM numbering
factory = rpi_gpio.KeypadFactory()
# Try factory.create_4_by_3_keypad
# and factory.create_4_by_4_keypad for reasonable defaults
keypad = factory.create_keypad(keypad=KEYPAD, row_pins=ROW_PINS, col_pins=COL_PINS)
def printKey(key):
print(key)
# printKey will be called each time a keypad button is pressed
keypad.registerKeyPressHandler(printKey)
When your program exits, call keypad.cleanup()
to ensure the Raspberry Pi's GPIO pins are reset.
Licensed under GNU Lesser General Public License Version 3 (LGPL v3).