daandavidsz/wshare-touchscreen

Waveshare touchscreen user space driver

wshare-touchscreen

Waveshare touchscreen user space driver

I brought a Waveshare 7-inch HDMI LCD and it provides touchscreen through USB. Unfortunately, dvd with raspbian images for raspberry was completely unreadable, so I decided to google problem and have found solution.

But I thought, that writing driver in Python is completely bad idea, and that driver imitated just mouse, not touchscreen, as I needed for my project. So, I decided to implement user space uinput driver, that implements simple (type A) protocol from linux documetation.

Dependencies:

• libsuinput, version >= 0.6.1
• pthread
• C99 compiler
• libudev

Compile:

gcc -std=c99 -Wall ./waveshare.c -pthread -lsuinput -ludev -o waveshare-touch-driver

Install

1. Copy file to the path

   sudo cp waveshare-touch-driver /usr/local/bin/waveshare-touch-driver

2. Edit /etc/rc.local file and append:

   /usr/local/bin/waveshare-touch-driver

3. Edit /etc/modules and append neccessary uinput kernel module

4. Reboot

Restrictions

• Sometimes touchscreen is really buggy. This driver does not perform any data correction
• For now "clean" /dev/input/eventX source is almost useless for X applications, and you should use additional driver for implementing touchscreen support in X. However it is useful to launch Qt applications in EGLFS mode. Just add QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS=/dev/input/eventX to environment variables (where X is device number)