mc56f84550 motor speed control

Hi everyone !

I've bought a non working washing machine, model Beko WDW85122 (France) with a AC three phase induction motor, controlled by its own circuit board powered by a mc56f84550 microcontroller(datasheet).
I think I have no hope to repair the main circuit board, based on a ATmege128A, which I have repair the power supply, but still not work, when I plug in to AC, it sends a beep, but not start.

So I prefer to try to make a new circuit board based on a NANO board to control the entire washing machine, but I cannot make the AC motor inverter, which is more difficult than I/O or analog sensor gesture...So I want to reuse the existing one.

By a retro-ingenering I found that the MC56F84550 communicates via its UART interface, isolated by optocouplers.

I have connected a USB/TTL adapter to it, the board sends every 1sec a signal, I've tryed with different standard baud rate( 110, 300, 600,...) but its never the same data...

So my questions is : there is a existing protocol to communicate with a motor controller? And how can I determine the baud rate of this communication?

Thanks by advance for your answers :slight_smile: