The screen is TTL level and it works fine.
Schema is:
HMI: MCU:
GND
+5V
D0ut — RX118
DIn — TX119
It is only when I do a cold start (power down to up) in parallel on the MCU and on the HMI that sometimes the HMI starts but do not interpret the command send by the MCU.
I have to reset the HMI by pressing the rear reset button and then it runs correctly.
Thanks！