HAL_UARTEx_ReceiveToIdle_DMA return HAL_ERROR when stm32's partner restart

[Yang Yang]

Hello, ST experts

HAL_UARTEx_ReceiveToIdle_DMA works well in our project, it can get idle interrupt or uart data stream interrupt. But when STM32's partner power down and up again, I think that means UART_RX line to STM32 goes low during this period, the call of HAL_UARTEx_ReceiveToIdle_DMA always returns an error code. How can I restore in such situation?

BR

Yang

[TDK]

Probably the UART has an error flag set. Look at the handle to see what state the peripheral is in. Implement HAL_UART_ErrorCallback. Deinitialize/reinitialize UART if needed.

[Andrew Neil]

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@Yang Yang wrote:

But when STM32's partner power down and up again,

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you will almost certainly get a glitch in such an event - you will often see this on a terminal as a "junk" character when something is plugged-in, unplugged, and/or power-cycled.

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@Yang Yang wrote:

the call of HAL_UARTEx_ReceiveToIdle_DMA always returns an error code.

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So what error code, exactly, does it return?

Quite likely, there will be a framing error and/or other UART errors - as @TDK suggested.

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@Yang Yang wrote:

How can I restore in such situation?

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Make sure you properly handle glitches on the line - including UART errors, etc ...