USB HID mouse¶
This sample app demonstrates use of a USB Human Interface Device (HID) driver by the Zephyr project. This very simple driver enumerates a board with a button into a mouse that has a left mouse button and optionally (depending on the number of buttons on the board) a right mouse button, X-axis movement, and Y-axis movement. If the USB peripheral driver supports remote wakeup feature, wakeup request will be performed on every button click if the bus is in suspended state. This sample can be found under samples/subsys/usb/hid-mouse in the Zephyr project tree.
This project requires an USB device driver and uses the Input API.
There must be a
gpio-keys group of buttons or keys defined at
the board level that can generate input events, otherwise the example will build
but not work as expected.
The key mapping in the sample is as follows:
INPUT_KEY_0: left button
INPUT_KEY_1: right button
INPUT_KEY_2: move the mouse along the x-axis
INPUT_KEY_3: move the mouse along the y-axis
An LED must also be configured via the
led0 devicetree alias. You may also
see this error if you try to build this sample for an unsupported board:
Unsupported board: led0 devicetree alias is not defined
Building and Running¶
This sample can be built for multiple boards, in this example we will build it for the nucleo_f070rb board:
west build -b nucleo_f070rb samples/subsys/usb/hid-mouse
After you have built and flashed the sample app image to your board, plug the board into a host device, for example, a PC running Linux. The board will be detected as shown by the Linux dmesg command:
dmesg | tail -10 usb 2-2: new full-speed USB device number 2 using at91_ohci usb 2-2: New USB device found, idVendor=2fe3, idProduct=0007, bcdDevice= 2.03 usb 2-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3 usb 2-2: Product: Zephyr HID mouse sample usb 2-2: Manufacturer: ZEPHYR usb 2-2: SerialNumber: 86FE679A598AC47A input: ZEPHYR Zephyr HID mouse sample as /devices/soc0/ahb/600000.ohci/usb2/2-2/2-2:1.0/0003:2FE3:0100.0001/input/input0 hid-generic 0003:2FE3:0100.0001: input: USB HID v1.10 Mouse [ZEPHYR Zephyr HID mouse sample] on usb-at91-2/input0
You can also monitor mouse events by using the standard Linux
(see the Ubuntu evtest man page for more information about this tool):
sudo evtest /dev/input/event0 Input driver version is 1.0.1 Input device ID: bus 0x3 vendor 0x2fe3 product 0x7 version 0x110 Input device name: "ZEPHYR Zephyr HID mouse sample" Supported events: Event type 0 (EV_SYN) Event type 1 (EV_KEY) Event code 272 (BTN_LEFT) Event code 273 (BTN_RIGHT) Event code 274 (BTN_MIDDLE) Event type 2 (EV_REL) Event code 0 (REL_X) Event code 1 (REL_Y) Event code 8 (REL_WHEEL) Event type 4 (EV_MSC) Event code 4 (MSC_SCAN) Properties: Testing ... (interrupt to exit)
When you press the button on your board, it will act as if the left
mouse button was pressed, and this information will be displayed
Event: time 1167609663.618515, type 4 (EV_MSC), code 4 (MSC_SCAN), value 90001 Event: time 1167609663.618515, type 1 (EV_KEY), code 272 (BTN_LEFT), value 1 Event: time 1167609663.618515, -------------- SYN_REPORT ------------ Event: time 1167609663.730510, type 4 (EV_MSC), code 4 (MSC_SCAN), value 90001 Event: time 1167609663.730510, type 1 (EV_KEY), code 272 (BTN_LEFT), value 0 Event: time 1167609663.730510, -------------- SYN_REPORT ------------
If your board has more than one button, they will act as right mouse button, X-axis movement, and Y-axis movement.