How to manage two UART (USART2 and USART1) under Interrupt

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There are different possibility to use the UART under Interrupt, for instance use PRINTF but this mode use a loot of code or, more efficiency is to use the Call Back.

In this example we use the Call Back modality.

This project was tested on NUCLEO-F030R8, was developed using the Cube-MX and the project is for ATOLLIC.
Thanks to Cube-MX is easy move this project on other STM32 mcu but also generate the same project for other IDE (KEIL, IAR, etc)

For use this project connect the NUCLEO-F030R8 to PC and use a terminal emulator, we suggest TeraTerm.
This because the USART2 is transferred to the PC like a USB virtual com port.

Here there is the Cube-MX project.

In this project we use only the USART2 because it is connected to the PC via the ST-LINK-v2 present on the NUCLEO-F030R8.
The USART1 is already configured for work under Interrupt but is not used.
This project send a buffer (10 characters) via USART2 and receive a buffer (via USART2) from the PC (10 characters).

After the Cube-MX has generated the project, here there is the Cube-MX project, is necessary insert some lines of code for configura the call back and the USART. See below.

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N.1 – After the:

/* USER CODE BEGIN PV */
/* Private variables ———————————————————*/

insert the lines below:

uint8_t buffer_tx[10]={69, 77, 67, 85, 46, 69, 85, 13, 10}; 
uint8_t buffer_rx[10];

/* USER CODE END PV */

N.2 – After the:

/* USER CODE BEGIN 0 */

insert the lines below:

void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
{
}

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
 if(huart->Instance==USART1)
 {
 while(1);
 }

if(huart->Instance==USART2)
 {
 while(1);
 }
}

/* USER CODE END 0 */

N.3 – After the:

/* USER CODE BEGIN 2 */

insert the lines below:

HAL_UART_Receive_IT(&huart2, buffer_rx, 10);
HAL_UART_Transmit_IT(&huart2, buffer_tx, 10);

/* USER CODE END 2 */

How to test this example

Compile and strat Debug.

Insert two breakpoint in the correspondence of the:
while(1);
see point 1 e 2 below.

Next insert in the watch Expression tab the variable: buffer_rx
see below.

Run your code, see the red arrow below.

Open TeraTerm and configure it as shown below.
Choose a right com port.

Stop your program and restart it, on TeraTerm you must see something like below.

Now type 10 characters in the TeraTerm, for example:
1 2 3 4 5 6 7 8 9 0

The debug mast stop at line n.86 and in the variable buffer_rx must contain the characters that you typed in TeraTerm window.
See below.

That is all, now try you to insert a similar action using USART1.

 

How to get the SW for this project

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Get the SW clicking here, but remember to ask us the password for open it.

Note: the project contain also the file for CUBE-MX