A question about UART interrupt

[Taehyeong Gu]

Posted on April 18, 2017 at 14:45

In order to configure UART interrupt receive, I put HAL_UART_Receive_IT function in HAL_UART_RxCpltCallback.

but it doesnt work. below is my callback code.

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)

{ uint8_t i; if (huart->Instance == USART2) //current UART { if (Rx_indx==0) {for (i=0;i<RXBUFFERBYTE;i++) aRxBuffer[i]=0;} //clear Rx_Buffer before receiving new data if (Rx_data[0]!=10) //if received data different from ascii 10 { aRxBuffer[Rx_indx++]=Rx_data[0]; //add data to Rx_Buffer } else //if received data = 10 { Rx_indx=0; USART2_RX_STANBY=1;//transfer complete, data is ready to read } if(HAL_UART_Receive_IT(&huart2,Rx_data, 1) != HAL_OK)//activate UART receive interrupt every time { Error_Handler(); } } }

The main program has HAL_UART_Receive_IT in beginning part. so i put some character of ASCII and my program reach if(HAL_UART_Receive_IT(&huart2,Rx_data, 1) != HAL_OK) . I checked that HAL_UART_Receive_IT returned HAL_OK then it means preparation of UART receive interrupt. 

but the program doenst take interrupt when I send ASCII to MCU.

I have no clue.. anyone who have had same experience??

help me please.

Thank you.

[Tesla DeLorean]

Posted on October 07, 2017 at 21:22

And you understand my point?

The post here

https://community.st.com/0D50X00009XkXwwSAF

is like transferring water from one side of the road to the other, where the water doesn't stop flowing, the fill/empty rate is the same and you only have a single 5 gallon bucket. When you move the bucket you lose 5 gallons of water.

You really need two buckets, and manage both of them at the same time. Or use a hose...

My loop above doesn't block, it services both streams if they are ready for a character, and the pumping process completes in a fractional byte time (because it also doesn't block).

If your process/parse time takes 12 character times, then consider a buffering scheme holding 20-24 characters in-flight at a time, to provide sufficient elasticity.

[Dimitris Paraskevopoulos]

Posted on October 07, 2017 at 22:11

Yes I understand the point even though this example makes it even more clear.

I wanted to point out that it is a bit funny that you replied with the same response.