implementation of RGBBus into lcd_bus.py

[favnec5]

hello,
I am very interested in your work, nice job !!
Currently the compilation of lv_micropython is very complicated, despite the considerable efforts of kdschlosser.
I'm using old version of lv_micropython.
With this in mind, would it be possible to implement the RGBBus class in lcd_bus.py ?
Obviously it will be slow...

Best regard,
Tom

[bdbarnett]

Hello,

I have only implemented SPIBus and I80Bus in MicroPython. Unlike SPI and i80 buses, RGB buses are very timing specific. If an RGBBus can be implemented in MicroPython code, I don't know how to do it. To use RGBBus, you have to use @kdschlosser's lcd_bus implementation written in C that gets compiled into the new binding. There's a lot going on behind the scenes in his new binding as well as the main repo at https://github.com/lvgl/lv_binding_micropython. I suspect @kdschlosser's fork will be merged into the main repo soon.

[kdschlosser]

The RGB timings can be tricky because of the buffering and needing to keep a stream going to the display at all times. This is where using multiple cores or DMA memory is a must because you need to be able to maintain writing data to the display and at the same time be rendering the new buffer data.

This is not something that would be possible to do from inside of Python because of the inability to start a task on the second core to handle this and also the inability to create and properly access DMA memory. It has to be done in C code.