ble_hid.rst

ble_hid - BLE HID

The ble_hid module provides access to the BLE Human Interface Device functionality.

Note

Make sure to enable the BLE HID functionality in :ref:`card10_cfg` and reboot your card10 if you want to use BLE HID.

Also make sure that the adafruit_hid folder from the card10 release archive is placed on the file system of your card10.

Warning

At least Ubuntu Linux will keep auto connecting to BLE HID devices once they are paired to the host computer. If you want to connect your card10 to a phone again, you might have to temporarily turn off Bluetooth on your computer.

An example application can be found in the preload directory (named HID Demo). It provides examples how to use the card10 as keyboard, mouse or volume control.

Please refer to the Adafruit CircuitPython HID library for examples how to use the HID service. The card10 implements the same HID descriptors as the Adafruit CircuitPython BLE library and should be compatible with all uses of the Adafruit CircuitPython HID library.

Example emulating a keyboard:

Adapted from https://github.com/adafruit/Adafruit_Learning_System_Guides/blob/master/CPB_Keybutton_BLE/cpb_keybutton_ble.py

A more complete version of this example can be found in the HID Demo app on your card10.

import ble_hid
from adafruit_hid.keyboard import Keyboard
from adafruit_hid.keyboard_layout_us import KeyboardLayoutUS
from adafruit_hid.keycode import Keycode

k = Keyboard(ble_hid.devices)
kl = KeyboardLayoutUS(k)

k.send(Keycode.BACKSPACE)

# use keyboard_layout for words
kl.write("Demo with a long text to show how fast a card10 can type!")

# add shift modifier
k.send(Keycode.SHIFT, Keycode.F19)

Example emulating a mouse:

import ble_hid
import bhi160
import buttons
from adafruit_hid.mouse import Mouse

m = Mouse(ble_hid.devices)

def send_report(samples):
    if len(samples) > 0:
        x = -int(samples[0].z)
        y = -int(samples[0].y)
        m.move(x, y)

sensor = bhi160.BHI160Orientation(sample_rate=10, callback=send_report)

b_old = buttons.read()
while True:
    b_new = buttons.read()
    if not b_old == b_new:
        print(b_new)
        b_old = b_new
        if b_new == buttons.TOP_RIGHT:
            m.click(Mouse.MIDDLE_BUTTON)
        elif b_new == buttons.BOTTOM_RIGHT:
            m.click(Mouse.RIGHT_BUTTON)
        elif b_new == buttons.BOTTOM_LEFT:
            m.click(Mouse.LEFT_BUTTON)

Note

Make sure to catch OSError exceptions in real applications. The exception will be thrown if there is connection to the host (or if it is lost) and you want to send an event.