STM32F030F4Px USART problem

[NSing.5]

i'm using STM32F030F4Px for MODBUS Master Slave communication based on USART (RS485 communication). i'm using 9600 baud rate, 8bit 1 stop bit communication with DMA and HAL.

Master is transmitting 8 bytes to slave after 10 or 20 msec which are received at slave end perfectly.

However, when slave responds to master, the slave stops receiving data from master.

[Karl Yamashita]

1st thing, post your code

[NSing.5]

as suggested, the main file is attached here. i would like to share, that when i'm using STM32F730 (as a slave) with same program it is working perfectly. However, in that case the master (STM32F0) is not receiving response.

Regards

[NSing.5]

as suggested, the main file is attached here. i would like to share, that when i'm using STM32F730 (as a slave) with same program it is working perfectly. However, in that case the master (STM32F0) is not receiving response.

Regard

[Pavel A.]

Have you tried to debug the master? When the master "is not receiving response", maybe it has crashed?

[NSing.5]

I'VE CHECKED IT. The master is continuously transmitting to slave after a fixed duration. but not receiving response from slave (stm32f730)

[NSing.5]

sir are you able to diagnose it?

[Karl Yamashita]

When you call HAL_UARTEx_ReceiveToIdle_DMA you don't check for HAL status to be sure the interrupts were enable again.

Check this post where i share some code on how to check HAL status and set a flag if not successful. I check the flag in polling routine and try to enable the interrupt again. The same goes for transmitting, though I'm using HAL_UART_Transmit_IT instead of HAL_UART_Transmit_DMA, but checking HAL status would still be the same.

https://community.st.com/s/question/0D53W00002CeLaOSAV/cannot-receive-full-string-on-uart-receive-st32h745-disco-board