【STM32U385RG 测评】4、LPUART唤醒STOP低功耗模式

STM32U385RG的SDK中有LPUART唤醒STOP低功耗模式的例程位于：
STM32Cube_FW_U3_V1.2.0\Projects\NUCLEO-U385RG-Q\Examples\UART\LPUART_WakeUpFromStop
所以简单地修改下就可以实现本实验的功能

一、基本配置
1、引脚使用

2、PWR配置



3、LPUART1配置


4、中断配置


二、软件部分

1、LPUART1初始化
使能中断

复制

static void MX_LPUART1_UART_Init(void)

{



  /* USER CODE BEGIN LPUART1_Init 0 */



  /* USER CODE END LPUART1_Init 0 */



  /* USER CODE BEGIN LPUART1_Init 1 */



  /* USER CODE END LPUART1_Init 1 */

  hlpuart1.Instance = LPUART1;

  hlpuart1.Init.BaudRate = 115200;

  hlpuart1.Init.WordLength = UART_WORDLENGTH_8B;

  hlpuart1.Init.StopBits = UART_STOPBITS_1;

  hlpuart1.Init.Parity = UART_PARITY_NONE;

  hlpuart1.Init.Mode = UART_MODE_TX_RX;

  hlpuart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;

  hlpuart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;

  hlpuart1.Init.ClockPrescaler = UART_PRESCALER_DIV1;

  hlpuart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;

  hlpuart1.FifoMode = UART_FIFOMODE_DISABLE;

  if (HAL_UART_Init(&hlpuart1) != HAL_OK)

  {

    Error_Handler();

  }

  if (HAL_UARTEx_SetTxFifoThreshold(&hlpuart1, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)

  {

    Error_Handler();

  }

  if (HAL_UARTEx_SetRxFifoThreshold(&hlpuart1, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)

  {

    Error_Handler();

  }

  if (HAL_UARTEx_DisableFifoMode(&hlpuart1) != HAL_OK)

  {

    Error_Handler();

  }

  /* USER CODE BEGIN LPUART1_Init 2 */

#ifdef BOARD_IN_STOP_MODE

  LPUART1_EXTI_ENABLE_IT();

#endif /* BOARD_IN_STOP_MODE */

  /* USER CODE END LPUART1_Init 2 */



}

2、LPUART_RX中断处理

复制

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)

{

  UserReceptionComplete = 1;

}

RX收到数据，设置标志UserReceptionComplete = 1。

3、main函数

复制

 BSP_LED_On(LD2);



  /* wait for two seconds before test start */

  HAL_Delay(2000);



  /* Disable Debug during Stop mode */

  HAL_DBGMCU_DisableDBGStopMode();



  /* Enable MCU wake-up by LPUART */

  HAL_UARTEx_EnableStopMode(&hlpuart1);



  /*##-1- Put UART peripheral in reception process ###########################*/

  if (HAL_UART_Receive_IT(&hlpuart1, (uint8_t *)aRxBuffer, RXBUFFERSIZE) != HAL_OK)

  {



      Error_Handler();

  }



  /* about to enter STOP mode: switch off LD2 */

  BSP_LED_Off(LD2);



  /* enter STOP mode */

  HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI);



  /* The board receives the message from the other board. Message reception wakes up the board. */

  /* Switch On LD2 */

  BSP_LED_On(LD2);



  /* At that point, MCU has been awoken: LD2 has been turned back on ; Wake Up based on RXNE flag successful */

  SystemClock_Config_fromSTOP();



  /* Disable MCU wake-up by LPUART */

  HAL_UARTEx_DisableStopMode(&hlpuart1);



  /* Wait for reception complete callback */

  while (UserReceptionComplete == 0)

  {

  }



  /*##-2- Start the transmission process #####################################*/

  /* Send back received buffer */

  if (HAL_UART_Transmit_IT(&hlpuart1, (uint8_t *)aRxBuffer, RXBUFFERSIZE) != HAL_OK)

  {



    Error_Handler();



  }

进入STOP模式：HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI);
设置LPUART1结束STOP模式使能：HAL_UARTEx_EnableStopMode(&hlpuart1);

4、while(1)

复制

  while (1)

  {

                BSP_LED_Toggle(LD2);

                HAL_Delay(1000);

    /* USER CODE END WHILE */



    /* USER CODE BEGIN 3 */

  }

  /* USER CODE END 3 */

}

退出stop后，进入while(1)，没隔1秒翻转LD2。


三、运行

LPUART（PA2、PA3）和串口工具连接



1、按reset开机，几秒后开发板进入Stop模式，电流0.3mA左右
2、PC机通过串口工具向LPUART1发送"hello world"，MCU被唤醒，PC机接收返回的"hello world"，此时电流1.0mA左右
3、板载LD2每1秒翻转1次

了解LPUART唤醒STOP低功耗模式