is there any way to get interrupt on data ready in UART buffer in HAL library........?

You can use HAL_UART_Receive_IT( &huart1, &ch, 1 ); to receive a single char ch. When using HAL, the interrupt is wrapped for you in a callback. You implement at global level:

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
	if(huart->Instance==USART1) {
		// process ch
		HAL_UART_Receive_IT( &huart1, &ch, 1 );	// receive next char
	}
}

There are more callbacks available, see HAL stm32f0xx_hal_uart.h

This works well if the throughput is low or moderate. For high throughput you might want to switch to DMA handling more than 1 char per interrupt. The most elaborated examples I know of are from Tilen Majerle https://stm32f4-discovery.net/2017/07/stm32-tutorial-efficiently-receive-uart-data-using-dma/

hth

KnarfB

KnarfB,

according to my understating this HAL_UART_RxCpltCallback is interrupted when a reception complete.then how this will get its first interrupt......?

Correct. For starting, you call HAL_UART_Receive_IT( &huart1, &ch, 1 ); once in main().

Unfortunately there is no such functionality in the HAL library.

The workaround presented above is a serious waste of the limited flash and ram space and processing power of the STM32F0, unnecessarily checking flags again and again, needlessly disabling and enabling interrupts after each received byte, etc.

Using the code examples in appendix A, setting up the UART is 2 lines of code, interrupt handling is another 2 lines (receive byte code example goes directly in UART1_IRQHandler()).

Where i get this code examples appendix A....?

It is easy to write your own ISRs that conpletely skip all the hal callback faff.

Here's what i do:​

1. Look in the interrupt vector ​table to get the name of the interrupt you want to use

2: declare a void [isr name] ( void ) function in your code. This is your isr.

3. Build the code and then delete/ comment out the old definition of the isr when the linker complains & rebuild.

​

This, of course, isn't the only approach, just what i did at first​