Hello,
We are switching from RS232 to RS485 and are encountering problems. Everything worked properly with RS232
After initializing the USART (we are using Cube), transmitting is working fine.
Reception is handled by interrupt. After calling HAL_UART_Receive_IT, callback is instantly called even if nothing is connected to the transceiver and no signal is observed on RX (with the scope). After that, the UART is in error (error callback is also called, sometime its frame error, sometime overruns) and its impossible to receive characters from uart or transmit.
I observed signals with the scope: when transmitting, DE and TX are perfect (before activating the interrupt on rx) and I receive the data on my computer.
When I transmit from the computer, I also see the correct RX.
I don't understand why the rx transfer complete callback is called after enabling the IT...
Do you know from where does it could come from?
Thank you,
Charles
