the initialization of uart4

The initialization of UART4 can vary depending on the microcontroller or development board being used. However, here is an example of how to initialize UART4 on a STM32F4 Discovery board using CubeMX and HAL libraries:

1. Open CubeMX and create a new project for your microcontroller or development board.

2. In the "Pinout & Configuration" tab, select "UART4" from the peripherals list.

3. Enable the "Asynchronous" mode and set the baud rate to the desired value.

4. Set the word length, stop bits, and parity according to your application's requirements.

5. Configure the GPIO pins for the UART4 peripheral by selecting the appropriate pins in the "Pinout" tab.

6. Generate the code by clicking on the "Generate" button.

7. Open the generated code and locate the "MX_UART4_Init" function.

8. In this function, you will find the initialization code for UART4. It will look something like this:

  huart4.Instance = UART4;
  huart4.Init.BaudRate = 115200;
  huart4.Init.WordLength = UART_WORDLENGTH_8B;
  huart4.Init.StopBits = UART_STOPBITS_1;
  huart4.Init.Parity = UART_PARITY_NONE;
  huart4.Init.Mode = UART_MODE_TX_RX;
  huart4.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart4.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart4) != HAL_OK)
  {
    Error_Handler();
  }

9. This code initializes UART4 with a baud rate of 115200, 8 data bits, 1 stop bit, no parity, and both transmit and receive modes enabled.

10. You can now use the HAL functions to send and receive data over UART4. For example, to transmit a string over UART4, you can use the following code:

  char* str = "Hello, World!";
  HAL_UART_Transmit(&huart4, (uint8_t*)str, strlen(str), HAL_MAX_DELAY);

This will send the string "Hello, World!" over UART4.