STM32H747I-DISCO Virtual Com USART Example

[Louie88]

Hi,

If I understand right USART1 is used in STM32H747I-DISCO board for VCOM. I could not find any example for my board. I would like to want for an 8-byte host command using:

HAL_UART_Receive_IT(&huart1, hostCommand.buffer, 8);

 Once a command is received then I process it, I create the answer and wait for the next command. So simple. 

Noe: on CN13 pin 13 I see the command from my PC on scope, but the HAL_UART_RECEIVE_IT() never receives anything. 

Can sombody send me a short example?

Thanks,

Louie

[Louie88]

Okay I did not know that. This is why I originally asked for an example app. I will try it using your way.

Thanks,

Louis

[Andrew Neil]

The examples in CubeIDE/CubeMX would illustrate that.

[Tesla DeLorean · Accepted solution]

void USART1_IRQHandler(void) // gets called per byte/interrupt
{
  HAL_UART_IRQHandler(&huart1); // calls into HAL, it works the buffering and calls your call-back when complete
}


void HAL_UART_RxCpltCallback(UART_HandleTypeDef *UartHandle) // call from HAL_UART_IRQHandler
{
  // Do something with the filled buffer
  ..

  HAL_UART_Receive_IT(&huart1, hostCommand.buffer, 8); // initate again (returns immediately)
}


void HAL_UART_ErrorCallback(UART_HandleTypeDef *UartHandle)
{
  Error_Handler(); // or manage failure
}

main()
{
  ..

  HAL_UART_Receive_IT(&huart1, hostCommand.buffer, 8); // start (returns immediately)

  while(1);
}

[Karl Yamashita]

---

However I noticed the followings:

• TouchGFX Created the project in C:\TouchGFXProjects\RCTDigitalClock folder which is out of my default workspace (C:\Users\[UserName]\STM32CubeIDE\workspace_1.17.0\RCTDigitalClock . 
• TouchGFX Created a `STM32CubeIDE` folder with CM4 and CM7 folders.
• TouchGFX Created a `STM32H747I-DISCO.ioc` file. Why not RCTDigitalClock.ioc?

---

• The first one is normal.
• The second one is normal.
• The third one has been like this since ST acquired TouchGFX. This is very annoying because if you have several TGFX projects using the same board, you can only import 1 at a time. This is because STM32CubeIDE does not allow the same project name to be opened simultaneously. Surprisingly, to this day, ST still can't seem to fix this annoyance. Here is a video that shows how to rename the projects to a useable name including the IOC file. 

STM32F429I-DISCO & TouchGFX Setup 

---

When I enabled the USART1 then STM32CubeMX automatically created PB7 as Rx pin. This is the bug or issue or whatever you call it. This was teste at least 20 times.

---

This is not a bug. I get the same results when enabling USART1 from a TGFX project. Now this could be because the IOC file was generated by TGFX, not by STM32CubeIDE. As I said before, you can override and select the available Rx pins for USART1.

But, if you start a new board project in STM32CubeIDE/CubeMX, and not a TGFX project, it gives you an option to initialize default configurations. When you enable default configurations, then PA9 and PA10 are selected for USART1.

[Andrew Neil]

---

@Andrew Neil wrote:

The examples in CubeIDE/CubeMX would illustrate that.

---

Apparently not for that exact board:

[Louie88]

Thanks Tesla DeLorean, this is what I really asked for. 

Louis

[Louie88]

Thanks for the demo.

Louis