• Source

/* USER CODE BEGIN PFP */
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
/* USER CODE END PFP */
…
  /* USER CODE BEGIN WHILE */
  while (1)
  {
         printf("Hello World\n\r");
         HAL_Delay(1000);
    /* USER CODE END WHILE */

…
/* USER CODE BEGIN 4 */
/**
  * @brief  Retargets the C library printf function to the USART.
  * @param  None
  * @retval None
  */
PUTCHAR_PROTOTYPE
{
  /* Place your implementation of fputc here */
  /* e.g. write a character to the USART1 and Loop until the end of transmission */
  HAL_UART_Transmit(&huart2, (uint8_t *)&ch, 1, 0xFFFF);

  return ch;
}

/* USER CODE END 4 */