[STM32U3] 【STM32U385RG 测评】基础任务2 基于低功耗串口测试

根据评测任务，此次测试需要用到低功耗串口，我这里使用lpuart1做为测试口，根据原理图，他接到PA2、PA3

1、串口初始化：

1. static void MX_LPUART1_UART_Init(void)
2. {
3. /* USER CODE BEGIN LPUART1_Init 0 */
4. /* USER CODE END LPUART1_Init 0 */
5. /* USER CODE BEGIN LPUART1_Init 1 */
6. /* USER CODE END LPUART1_Init 1 */
7. hlpuart1.Instance = LPUART1;
8. hlpuart1.Init.BaudRate = 115200;
9. hlpuart1.Init.WordLength = UART_WORDLENGTH_8B;
10. hlpuart1.Init.StopBits = UART_STOPBITS_1;
11. hlpuart1.Init.Parity = UART_PARITY_NONE;
12. hlpuart1.Init.Mode = UART_MODE_TX_RX;
13. hlpuart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
14. hlpuart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
15. hlpuart1.Init.ClockPrescaler = UART_PRESCALER_DIV1;
16. hlpuart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
17. hlpuart1.FifoMode = UART_FIFOMODE_DISABLE;
18. if (HAL_UART_Init(&hlpuart1) != HAL_OK)
19. {
20. Error_Handler();
21. }
22. if (HAL_UARTEx_SetTxFifoThreshold(&hlpuart1, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
23. {
24. Error_Handler();
25. }
26. if (HAL_UARTEx_SetRxFifoThreshold(&hlpuart1, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
27. {
28. Error_Handler();
29. }
30. if (HAL_UARTEx_DisableFifoMode(&hlpuart1) != HAL_OK)
31. {
32. Error_Handler();
33. }
34. /* USER CODE BEGIN LPUART1_Init 2 */
35. #ifdef BOARD_IN_STOP_MODE
36. LPUART1_EXTI_ENABLE_IT();
37. #endif /* BOARD_IN_STOP_MODE */
38. /* USER CODE END LPUART1_Init 2 */
39. }

2、同时为了显示LED，初始化led2

复制

1. BSP_LED_Init(LD2);

3、配置低功耗时钟：

复制

1. void SystemClock_Config_fromSTOP(void)
2. {
3. RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
4. RCC_OscInitTypeDef RCC_OscInitStruct = {0};
5. uint32_t pFLatency = 0;
6. /* Get the Oscillators configuration from the internal RCC registers */
7. HAL_RCC_GetOscConfig(&RCC_OscInitStruct);
8. /* Wake up on HSI, re-enable PLL with HSI as source */
9. /* Oscillator configuration unchanged */
10. RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
11. RCC_OscInitStruct.HSIState = RCC_HSI_ON;
12. RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
13. if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
14. {
15. Error_Handler();
16. }
17. /* Get the clock prescalers configuration from the internal RCC registers */
18. HAL_RCC_GetClockConfig(&RCC_ClkInitStruct, &pFLatency);
19. RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
20. |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2
21. |RCC_CLOCKTYPE_PCLK3;
22. RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
23. RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
24. RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
25. RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
26. RCC_ClkInitStruct.APB3CLKDivider = RCC_HCLK_DIV1;
27. if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, pFLatency) != HAL_OK)
28. {
29. Error_Handler();
30. }
31. }

4、测试程序设计，在主程序中，首先延时2秒，然后开启低功耗串口的接收中断，然后进入低功耗模式，关闭LD2，当有串口数据接收后，周期闪烁，闪烁10次，如果没有数据再次进入，则再次进入低功耗模式。

复制

1. /* LD2 is on till stop mode */
2. BSP_LED_On(LD2);
3. /* wait for two seconds before test start */
4. HAL_Delay(2000);
5. /* Disable Debug during Stop mode */
6. HAL_DBGMCU_DisableDBGStopMode();
7. /* Enable MCU wake-up by LPUART */
8. HAL_UARTEx_EnableStopMode(&hlpuart1);
9. /*##-1- Put UART peripheral in reception process ###########################*/
10. if (HAL_UART_Receive_IT(&hlpuart1, (uint8_t *)aRxBuffer, RXBUFFERSIZE) != HAL_OK)
11. {
12. Error_Handler();
13. }
14. /* about to enter STOP mode: switch off LD2 */
15. BSP_LED_Off(LD2);
16. /* enter STOP mode */
17. HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI);
18. /* The board receives the message from the other board. Message reception wakes up the board. */
19. /* Switch On LD2 */
20. BSP_LED_On(LD2);
21. /* At that point, MCU has been awoken: LD2 has been turned back on ; Wake Up based on RXNE flag successful */
22. SystemClock_Config_fromSTOP();
23. /* Disable MCU wake-up by LPUART */
24. HAL_UARTEx_DisableStopMode(&hlpuart1);
25. #endif /* !BOARD_IN_STOP_MODE */
26. /* USER CODE END 2 */
27. /* Infinite loop */
28. /* USER CODE BEGIN WHILE */
29. while (1)
30. {
31. BSP_LED_Off(LD2);
32. HAL_Delay(500);
33. BSP_LED_On(LD2);
34. HAL_Delay(500);
35. cnt++;
36. if(cnt >10)
37. {
38. /* Disable Debug during Stop mode */
39. HAL_DBGMCU_DisableDBGStopMode();
40. /* Enable MCU wake-up by LPUART */
41. HAL_UARTEx_EnableStopMode(&hlpuart1);
43. /*##-1- Put UART peripheral in reception process ###########################*/
44. if (HAL_UART_Receive_IT(&hlpuart1, (uint8_t *)aRxBuffer, RXBUFFERSIZE) != HAL_OK)
45. {
46. Error_Handler();
47. }
49. /* about to enter STOP mode: switch off LD2 */
50. BSP_LED_Off(LD2);
51. /* enter STOP mode */
52. HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI);
53. /* The board receives the message from the other board. Message reception wakes up the board. */
54. /* Switch On LD2 */
55. BSP_LED_On(LD2);
56. /* At that point, MCU has been awoken: LD2 has been turned back on ; Wake Up based on RXNE flag successful */
57. SystemClock_Config_fromSTOP();
58. /* Disable MCU wake-up by LPUART */
59. HAL_UARTEx_DisableStopMode(&hlpuart1);
60. cnt = 0;
61. }
62. /* USER CODE END WHILE */
63. /* USER CODE BEGIN 3 */
64. }
65. /* USER CODE END 3 */

【测试】
我使用微安表进行测试，在正常工作时工作电流为1.1MA，进入低功耗时电流为400uA，使用串口发送数据后，可以正常唤醒。

---------------------
作者：lulugl
链接：https://bbs.21ic.com/icview-3481350-1-1.html?_dsign=6d32beff
来源：21ic.com
此文章已获得原创/原创奖标签，著作权归21ic所有，任何人未经允许禁止转载。