class USB_HID – USB Human Interface Device (HID)

The USB_HID class represents the OpenMV Cam’s USB Human Interface Device interface. It can be used to emulate a peripheral such as a mouse or keyboard.

Before constructing a USB_HID object, call pyb.usb_mode() with a mode that includes HID (e.g. 'VCP+HID') – this enumerates the USB HID class on the host. The report descriptor passed to usb_mode selects the device class; pre-built tuples are available as pyb.hid_mouse and pyb.hid_keyboard.

Example – send a mouse left-click then move it 5 pixels right:

import pyb

pyb.usb_mode("VCP+HID", hid=pyb.hid_mouse)
hid = pyb.USB_HID()

# report layout: (buttons, dx, dy, wheel)
hid.send((1, 0, 0, 0))   # press left button
hid.send((0, 0, 0, 0))   # release
hid.send((0, 5, 0, 0))   # move +5 in X

Constructors

class pyb.USB_HID

Create a new USB_HID object. There is only one HID interface, so the constructor returns the singleton object.

Methods

send(data: Tuple[int, ...] | List[int] | bytes | bytearray) → None

Send an HID input report to the USB host.

data is a tuple/list of integers or a bytes-like buffer whose layout depends on the report descriptor in use. For the built-in mouse descriptor the report is (buttons, dx, dy, wheel); for the keyboard descriptor it is (modifiers, 0, key1, key2, key3, key4, key5, key6). See pyb.hid_mouse and pyb.hid_keyboard.

recv(data: int | bytearray, *, timeout: int = 5000) → bytes | int

Receive an HID output report from the USB host (e.g. keyboard LED state). Returns immediately if a report is already buffered.

• data is either an int (the number of bytes to read into a fresh buffer) or a mutable buffer to fill with received bytes.

• timeout is the maximum time in milliseconds to wait for a report.

If data is an integer a fresh bytes object is returned; otherwise the number of bytes written into data is returned.