Adafruit_CircuitPython_HID: A Python repository from c3c

Introduction

This driver simulates USB HID devices. Currently keyboard and mouse are implemented.

Dependencies

This driver depends on:

Adafruit CircuitPython

Please ensure all dependencies are available on the CircuitPython filesystem. This is easily achieved by downloading the Adafruit library and driver bundle.

Additional Layouts

This library has an en-US layout. Please check out and expand the library from Neradoc for additional layouts.

Usage Example

The Keyboard class sends keypress reports for a USB keyboard device to the host.

The Keycode class defines USB HID keycodes to send using Keyboard.

import usb_hid
from adafruit_hid.keyboard import Keyboard
from adafruit_hid.keycode import Keycode

# Set up a keyboard device.
kbd = Keyboard(usb_hid.devices)

# Type lowercase 'a'. Presses the 'a' key and releases it.
kbd.send(Keycode.A)

# Type capital 'A'.
kbd.send(Keycode.SHIFT, Keycode.A)

# Type control-x.
kbd.send(Keycode.CONTROL, Keycode.X)

# You can also control press and release actions separately.
kbd.press(Keycode.CONTROL, Keycode.X)
kbd.release_all()

# Press and hold the shifted '1' key to get '!' (exclamation mark).
kbd.press(Keycode.SHIFT, Keycode.ONE)
# Release the ONE key and send another report.
kbd.release(Keycode.ONE)
# Press shifted '2' to get '@'.
kbd.press(Keycode.TWO)
# Release all keys.
kbd.release_all()

The KeyboardLayoutUS sends ASCII characters using keypresses. It assumes the host is set to accept keypresses from a US keyboard.

If the host is expecting a non-US keyboard, the character to key mapping provided by KeyboardLayoutUS will not always be correct. Different keypresses will be needed in some cases. For instance, to type an 'A' on a French keyboard (AZERTY instead of QWERTY), Keycode.Q should be pressed.

Currently this package provides only KeyboardLayoutUS. More KeyboardLayout classes could be added to handle non-US keyboards and the different input methods provided by various operating systems.

import usb_hid
from adafruit_hid.keyboard import Keyboard
from adafruit_hid.keyboard_layout_us import KeyboardLayoutUS

kbd = Keyboard(usb_hid.devices)
layout = KeyboardLayoutUS(kbd)

# Type 'abc' followed by Enter (a newline).
layout.write('abc\n')

# Get the keycodes needed to type a '$'.
# The method will return (Keycode.SHIFT, Keycode.FOUR).
keycodes = layout.keycodes('$')

The Mouse class simulates a three-button mouse with a scroll wheel.

import usb_hid
from adafruit_hid.mouse import Mouse

m = Mouse(usb_hid.devices)

# Click the left mouse button.
m.click(Mouse.LEFT_BUTTON)

# Move the mouse diagonally to the upper left.
m.move(-100, -100, 0)

# Roll the mouse wheel away from the user one unit.
# Amount scrolled depends on the host.
m.move(0, 0, -1)

# Keyword arguments may also be used. Omitted arguments default to 0.
m.move(x=-100, y=-100)
m.move(wheel=-1)

# Move the mouse while holding down the left button. (click-drag).
m.press(Mouse.LEFT_BUTTON)
m.move(x=50, y=20)
m.release_all()       # or m.release(Mouse.LEFT_BUTTON)

The ConsumerControl class emulates consumer control devices such as remote controls, or the multimedia keys on certain keyboards.

import usb_hid
from adafruit_hid.consumer_control import ConsumerControl
from adafruit_hid.consumer_control_code import ConsumerControlCode

cc = ConsumerControl(usb_hid.devices)

# Raise volume.
cc.send(ConsumerControlCode.VOLUME_INCREMENT)

# Pause or resume playback.
cc.send(ConsumerControlCode.PLAY_PAUSE)

Contributing

Contributions are welcome! Please read our Code of Conduct before contributing to help this project stay welcoming.

Documentation