In this project I transformed the Nextion base programs from Arduino into the development environment of System Workbench with STM32CubeMX. I did not transform the NexUpload part because it only supports tft-files from an external SD card reader.
During the transmission of the data errors occurred again and again, so that I programmed an error redundancy. I could not find the cause, neither a level shifter nor a more powerful power supply could achieve an improvement.
harebit