I am trying to setup UART on an STM32L072CZTX. I am using interrupt mode and the interrupt seems to be firing due to a pause in main loop execution but nothing inside the interrupt seems to be occurring

[JGusl.1]

I am trying to setup UART on an STM32L072CZTX. In the ioc file I have setup the pins, RX is set to AF4 pullup, and TX is AF4 nopull. The interrupt is set to 0 and enabled. I have redefined the RxCpltCallback in the main and have events occur in there that work when run from main. I can see a pause in main execution (a simple blinking light) but nothing inside the interrupt seems to be happening, flags being set or a different LED blinking.

[waclawek.jan]

Polled UART Rx works?

A simple test, in main loop reading the UART Rx pin input state and setting/clearing LED accordingly, works?

LED blinky alone, works?

JW

[JGusl.1]

	//__HAL_UART_ENABLE_IT(&huart1, UART_IT_RXNE);
 
	//HAL_UART_Receive_IT(&huart1, UART_RX_BUFFER, 20);
 
	while (1)
	{
		HAL_UART_Receive(&huart1, UART_RX_BUFFER, 20, 10000);
		HAL_GPIO_WritePin(GPIOB, GREEN_LED, GPIO_PIN_SET);
		HAL_Delay(100);
		HAL_GPIO_WritePin(GPIOB, GREEN_LED, GPIO_PIN_RESET);

Sending a message doesn't cause the block to exit and blink

[JGusl.1]

Well im not even reading a low pin state at any time so something might be setup wrong with my hardware

[Karl Yamashita]

Yeah more than likely you don't have the GPIO's set up correctly.

[JGusl.1]

    GPIO_InitStruct.Pin = GPIO_PIN_9;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF4_USART1;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
 
    GPIO_InitStruct.Pin = GPIO_PIN_10;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_PULLUP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF4_USART1;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

this is how theyre set up

[waclawek.jan]

> this is how theyre set up

No. That is just some C code, calling other pieces of C code.

To find out how the GPIO is set up, read out and check/post content of its registers.

But check the HW first using continuity tester and oscilloscope.

JW​

[JGusl.1]

If this init process doesn't tell me then what's the point of using it

[Karl Yamashita]

See if the attached project works.

[waclawek.jan]

Well you have to set it up somehow, but when debugging, you always ​assume the relatively complex way from source code to executed binary may be wrong. The mcu works from the registers and not from C code, that's why the first thing when debugging is to read out registers and check.

But in your case, verify the hardware first.

JW​