USB HID Keyboard Example¶

Description¶

The USB HID Keyboard Example demonstrates use of a USB Human Interface Device (HID) driver by Adafruit.

The example code enumerates the nRF52840 M.2 Developer Kit into a HID keyboard that has an A key pressed by the USER button. The code depends on:

• adafruit_hid driver

Before you start coding, the Python Interpreter should be installed on the nRF52840 M.2 module correctly:

Install Python Interpreter

Run the code¶

Run the USB HID Keyboard Example by performing the following steps:

1. Connect the Module USB port to your PC as shown in the figure below. A disk drive called CIRCUITPY should be automatically detected by the computer:

   

2. The example code depends on the adafruit_hid driver. Download and extract it into your CIRCUITPY/lib folder. This should give you the following folder structure:

   CIRCUITPY
   ├── boot_out.txt
   ├── code.py
   └── lib
       └── adafruit_hid
           ├── __init__.py
           ├── keyboard.py
           └── keycode.py
   

3. Open the code.py file on your CIRCUITPY drive, then copy and paste the following code:

   import time
   import board
   import digitalio
   import usb_hid
   from adafruit_hid.keyboard import Keyboard
   from adafruit_hid.keycode import Keycode
   
   usb_keyboard = Keyboard(usb_hid.devices)
   
   button = digitalio.DigitalInOut(board.USR_BTN)
   button.direction = digitalio.Direction.INPUT
   button.pull = digitalio.Pull.UP
   
   last_value = button.value
   
   while True:
       if last_value != button.value:
           last_value = button.value
           if not button.value:
               print('Button is pressed')
               usb_keyboard.press(Keycode.A)
           else:
               print('Button is released')
               usb_keyboard.release(Keycode.A)
   

4. Your code will run as soon as the file is done saving. The board will enumerate as a HID keyboard. Press the USER button and observe that a letter a will output on the host computer.

Reference¶

• Adafruit_CircuitPython_HID Repository

Create an Issue¶

Interested in contributing to this project? Want to report a bug? Feel free to click here:

Create an Issue