[中文]

Linux Evdev Driver

Overview

The Linux event device (evdev) is a hardware-independent API that gives access to input events from, for example, a mouse or touchscreen. It is exposed via the Linux device file system interface.

Prerequisites

Your system has an input device configured (usually under /dev/input/ such as /dev/input/event0).

Configuring the driver

Enable the Linux LVGL evdev driver support in lv_conf.h.

#define LV_USE_EVDEV 1

Usage

To set up an event input, first create an input device with lv_edev_create setting it to the correct Linux event device. Then link this to the LVGL display with lv_indev_set_display.

lv_indev_t *touch = lv_evdev_create(LV_INDEV_TYPE_POINTER, "/dev/input/event0");
lv_indev_set_display(touch, disp);

Ensure that an lv_display_t object is already created for disp. An example for this is shown below, using the Linux framebuffer driver.

lv_display_t * disp = lv_linux_fbdev
lv_linux_fbdev_set_file(disp, "/dev/fb0");_create();

Locating your input device

If you can't determine your input device, first run

`$cat /proc/bus/input/devices`

This should show input devices and there will be entries with the word event which give a clue as to the device to use eg. event1 would be /dev/input/event1.

You can use evtest to show data from that event source to see if it is actually the one you want.

Try:

$evtest /dev/input/event1 replacing eventX with your event device from above.