I have a very critical application with BF561 with Color Sensors, BW Sensors, LCD etc. and also a UART. On the UART board I have connected a terminal with command polling from a customer device application. I always got buffer underrun on UART since UART has only a buffer of one byte. How to change Callback priority on UART to higher value than callback for PPI etc.! I am using the UART in none DMA Mode.