HAL_Delay in uart receive interrupt

[giwonKIM]

Hi

When HAL_Delay goes into uart interrupt, the program stops.

Is there a way to work it out?

I tried to use NVIC, but I don't know how to set it up.

Please advise. Thank you.

Here is my uart interrupt service routine.

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)

{

if(huart == &huart1)

{

uart_receivebuffer[uartidx++] = rx_buf;

if(rx_buf == 0x03)

{

HAL_Delay(100);

UartReceive();

}

HAL_UART_Receive_IT(&huart1, &rx_buf, 1);

}

}

[TDK · Accepted solution]

HAL_Delay needs SysTicks to keep firing to work.

Make your SysTick interrupt higher priority (numerically lower) than your UART interrupt priority. Like this:

It's generally frowned upon to have blocking code, or code that takes a long time to complete, within an interrupt handler, but that is a separate issue.

[giwonKIM]

Now it works!!

Really really thank you.

[gbm]

Nope, it doesn't. It's impossible to do anything practical (like implement any comm protocol) with any Delay() called from a UART ISR.

[Andrew Neil]

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@giwonKIM wrote:

 it works (sic)

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It may appear to "work" (sic)  in some trivial test case but, as the others have said, it is deeply flawed.

Why do you feel the need to have a delay in your ISR anyhow?