ReSearchITEng / pad4pi

Interrupt-based matrix keypad library for Raspberry Pi

pad4pi

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.

Usage

from pad4pi import rpi_gpio
import time # for loop

import subprocess # optional, for the subprocess (execute shell):
import shlex # optional, for the subprocess (execute shell):

KEYPAD = [
    ["1", "2", "3"],
    ["4", "5", "6"],
    ["7", "8", "9"],
    ["*", "0", "#"]
]

''' for 4x4 keypad:
KEYPAD = [
        ["1","2","3","A"],
        ["4","5","6","B"],
        ["7","8","9","C"],
        ["*","0","#","D"]
]'''

ROW_PINS = [4, 14, 15, 17] # BCM numbering
COL_PINS = [18, 27, 22] # BCM numbering # for 4x4 add "23"
# For pin numbering scheme and mapping to board pins: http://pinout.xyz/

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)
  if (key=="1"):
    print("number 1")
  elif (key=="A"):
    print("letter A")
    # Call a shell script:
    subprocess.call(shlex.split('./test.sh ' + key))

# printKey will be called each time a keypad button is pressed
keypad.registerKeyPressHandler(printKey)

# Loop, and cleanup at exit
try:
  while(True):
    time.sleep(0.2)
except:
 keypad.cleanup()

When your program exits, call keypad.cleanup() to ensure the Raspberry Pi's GPIO pins are reset.

License

Licensed under GNU Lesser General Public License Version 3 (LGPL v3).