Merge pull request #16 from adafruit/pi_keyboard

add examples/pi_keyboard.py

Author: ladyada

examples/mpr121_simpletest.py

@@ -11,8 +11,9 @@
 # Create I2C bus.
 i2c = busio.I2C(board.SCL, board.SDA)
 
-# Create MPR121 class.
+# Create MPR121 object.
 mpr121 = adafruit_mpr121.MPR121(i2c)
+
 # Note you can optionally change the address of the device:
 #mpr121 = adafruit_mpr121.MPR121(i2c, address=0x91)
 

examples/pi_keyboard.py

@@ -0,0 +1,120 @@
+#!/usr/bin/env python3
+
+# Adafruit Raspberry Pi MPR121 Keyboard Example
+# Author: Tony DiCola, Brennen Bearnes
+#
+# Allows you to turn touches detected by the MPR121 into key presses on a
+# Raspberry Pi.
+#
+# Dependencies
+# ============
+#
+# Make sure you have the required dependencies by executing the following commands:
+#
+#   sudo apt-get update
+#   sudo apt-get install build-essential python-dev python-pip libudev-dev
+#   sudo pip3 install python-uinput
+#   sudo pip3 install adafruit-circuitpython-mpr121
+#
+# Usage
+# =====
+#
+# To use this program you first need to connect the MPR121 board to the Raspberry
+# Pi (either connect the HAT directly to the Pi, or wire the I2C pins SCL, SDA to
+# the Pi SCL, SDA, VIN to Pi 3.3V, GND to Pi GND).
+#
+# Next define the mapping of capacitive touch input presses to keyboard
+# button presses.  Scroll down to the KEY_MAPPING dictionary definition below
+# and adjust the configuration as described in its comments.
+#
+# Finally run the script as root:
+#
+#   sudo python3 pi_keyboard.py
+#
+# Try pressing buttons and you should see key presses made on the Pi!  (Note
+# that you need to be logged directly into the Pi to see the keypresses -
+# over an SSH or console cable connection, you won't see anything.)
+#
+# Press Ctrl-C to quit at any time.
+#
+# Copyright (c) 2014-2019 Adafruit Industries
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+import logging
+import subprocess
+import time
+import board
+import busio
+import uinput
+import adafruit_mpr121
+
+# Define mapping of capacitive touch pin presses to keyboard button presses.
+
+# Each line here should define a dict entry that maps the capacitive touch
+# input number to an appropriate key press.
+#
+# For reference the list of possible uinput.KEY_* values you can specify is
+# defined in linux/input.h:
+# http://www.cs.fsu.edu/~baker/devices/lxr/http/source/linux/include/linux/input.h?v=2.6.11.8
+#
+# Make sure a cap touch input is defined only once or else the program will
+# fail to run!
+
+KEY_MAPPING = {
+    0: uinput.KEY_UP,
+    1: uinput.KEY_DOWN,
+    2: uinput.KEY_LEFT,
+    3: uinput.KEY_RIGHT,
+    4: uinput.KEY_B,
+    5: uinput.KEY_A,
+    6: uinput.KEY_ENTER,
+    7: uinput.KEY_SPACE,
+}
+
+# Sleep this long between polling for events:
+EVENT_WAIT_SLEEP_SECONDS = 0.25
+
+# Uncomment to enable debug message logging (might slow down key detection).
+logging.basicConfig(level=logging.DEBUG)
+
+# Make sure uinput kernel module is loaded.
+subprocess.check_call(['modprobe', 'uinput'])
+
+# Configure virtual keyboard.
+device = uinput.Device(KEY_MAPPING.values())
+
+# Create I2C bus.
+i2c = busio.I2C(board.SCL, board.SDA)
+
+# Create MPR121 object.
+mpr121 = adafruit_mpr121.MPR121(i2c)
+
+# Event loop to wait for pin changes and respond to them.
+print('Press Ctrl-C to quit.')
+while True:
+    # Loop through all defined inputs:
+    for pin, key in KEY_MAPPING.items():
+        # Call is_touched and pass it then number of the input.  If it's touched
+        # it will return True, otherwise it will return False.
+        if mpr121[pin].value:
+            logging.debug('Input %i touched!', pin)
+            logging.debug('Key: %s', key)
+            device.emit_click(key)
+    time.sleep(EVENT_WAIT_SLEEP_SECONDS)  # Small delay to keep from spamming output messages.