LVGL applications with mouse

Christian Mauderer oss at c-mauderer.de
Sat Jun 6 11:27:56 UTC 2020


On 06/06/2020 13:09, Vijay Kumar Banerjee wrote:
> On Fri, Jun 5, 2020 at 8:30 PM Christian Mauderer <oss at c-mauderer.de> wrote:
>>
>> Hello Vijay,
>>
>> On 04/06/2020 21:36, Vijay Kumar Banerjee wrote:
>>> Hi!
>>>
>>> I had been looking for an opportunity to do this for a long time and I'm
>>> excited to post that LVGL apps on RTEMS can now use input devices
>>> through the evdev interface!
>>
>> Sounds like a nice feature.
>>
>>>
>>> I prepared some BSD evdev patches for lvgl repository and managed to get
>>> them merged upstream. The patchset that I recently send to devel for
>>> libbsd[1] and rtems-littlevgl[2], updates the rtems-libbsd and
>>> rtems-littlevgl repository to adapt to the latest lvgl changes upstream
>>> and adds the evdev support to rtems-littlevgl.
>>>
>>> I wrote an example lvgl application that uses the mouse, connected
>>> through USB port of Beaglebone black. The example application uses the
>>> RTEMS logo, which makes it a bit heavier patch for the devel. I have
>>> posted the commit on my github fork [3] and would really appreciate it
>>> if someone can review and approve it to merge upstream.
>>
>> Although most likely touch screens are more common in embedded systems,
>> it's a good example. A lot of touchscreens should work via evdev too.
>>
> I couldn't work on the touchscreen due to the lack of hardware. The
> intention is indeed to enable the use of a touchscreen or mouse
> through evdev interface.
> Can you please test if the touchscreen works on BBB with evdev01.exe
> test in libbsd? If this works, I'll try to get the touchscreen model
> that you have (most probably after the lockdown is over :) ) and will
> integrate it into the same demo app.

I would have to try first whether the touch is supported in FreeBSD. I'm
not sure about that. But if you have tested one evdev device, another
one should work too. You did test that the interface between libbsd and
littelvgl works with the mouse.

> 
>> Regarding the logo size: Also an RTEMS logo is a nice idea, maybe
>> something smaller would be better to avoid that big file in the repo?
>> Depending on how you generated the image: Maybe some run length encoding
>> could reduce the size too (for example GIMP offers an option for that
>> when exporting images to C sources).
>>
> Thanks for pointing this out. This indeed lowered the size by half.
> I'm trying to get it working with lvgl and will post a patch to the
> list once I get it done.

Great.

> 
>>>
>>> Finally, please have a look at this very short video that shows the
>>> example application running. It uses many features of lvgl, including
>>> image, button, and input:
>>> https://blog.thelunatic.dev/assets/video/lvgl_rtems_logo.mp4
>>
>> Looks great.
>>
> Thanks.
> 
> Best regards,
> Vijay
>> Best regards
>>
>> Christian
>>
>>>
>>> We can now make full-fledged GUI applications with LVGL on RTEMS. :)
>>>
>>> [1]: https://lists.rtems.org/pipermail/devel/2020-June/060049.html
>>> [2]: https://lists.rtems.org/pipermail/devel/2020-June/060050.html
>>> [3]:
>>> https://github.com/thelunatic/rtems-examples/commit/c526d3c06a69591dc36e62af32728c51012ea6c1
>>>
>>> Thanks!
>>> Vijay
>>>
>>> _______________________________________________
>>> devel mailing list
>>> devel at rtems.org
>>> http://lists.rtems.org/mailman/listinfo/devel
>>>
> 


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