Commit 181ed70d authored by David Boddie's avatar David Boddie

Explain how to find the touchscreen input device

parent acba3e40
......@@ -12,14 +12,46 @@ is configured for LCD display and touchscreen input. Follow the procedure in
:ref:`imx8_devkit_lcd_display` to copy the correct file into place on the
development board.
Permissions
-----------
The commands and script given in the next section will need to be executed
using ``sudo`` unless the user is in the ``input`` group. We assume that the
user has been added to this group from this point onwards.
Receiving Touch Events
----------------------
Events from the touchscreen are delivered to the ``/dev/input/event1`` file.
One way to examine these events is to run the ``evtest`` command -- this will
need to be executed using ``sudo`` unless the user is in the ``input`` group::
Events from the touchscreen are typically delivered to the ``/dev/input/event1``
file. This can be verified by using the ``lsinput`` tool from the ``input-utils``
Debian package. Install and run the tool like this::
sudo apt install input-utils
lsinput
This should produce output like the following::
/dev/input/event0
bustype : BUS_HOST
vendor : 0x1
product : 0x1
version : 256
name : "gpio-keys"
phys : "gpio-keys/input0"
bits ev : (null) (null)
/dev/input/event1
bustype : BUS_I2C
vendor : 0x416
product : 0x1638
version : 256
name : "Goodix Capacitive TouchScreen"
phys : "input/ts"
bits ev : (null) (null) (null)
One way to examine these events is to run the ``evtest`` command::
sudo evtest /dev/input/event1
evtest /dev/input/event1
This will listen for events from the touchscreen and write them in
human-readable form to the console.
......
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