STM32 HAL PlatformIO LED blink example

In the autogenerated main.c, use the following while() loop:

/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
  /* USER CODE END WHILE */

  /* USER CODE BEGIN 3 */
  HAL_GPIO_WritePin(LD1_GPIO_Port, LD1_Pin, GPIO_PIN_SET);
  HAL_Delay(1000);
  HAL_GPIO_WritePin(LD1_GPIO_Port, LD1_Pin, GPIO_PIN_RESET);
  HAL_Delay(1000);
}
/* USER CODE END 3 */

On STM32H7 Nucleo boards, this will toggle the green LED.