stm32l476g-discovery ADC转换 USART

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bbbone 提问时间：2018-9-5 17:00 /

10ST金币

接着我的上一帖。我打算usart显示ADC转化后的数值 aResultDMA ，但是依旧有问题(显示0.000，如图所示)。求大神指导啊，V：chongzi15896main.c 文件内容：

1. #include "stm32l476g_discovery.h"

2. #include "stm32l476xx.h"

3. #include "stm32l4xx_hal_conf.h"

4. #include "adc.h"

5. #include "SysClock.h"

6. #include "LED.h"

7. #include "UART.h"

8. #include "main.h"

9. #include "string.h"

10. #include "stdio.h"

11.

12. char RxComByte = 0;

13. uint8_t buffer[BufferSize];

14. /* ADC handle declaration */

15. ADC_HandleTypeDef AdcHandle;

16.

17. /* ADC channel configurationstructure declaration */

18. ADC_ChannelConfTypeDef sConfig;

19.

20. /* Converted value declaration */

21. uint32_t aResultDMA;

22.

23. int main(void){

24.

25. int a,n,i;

26. float b;

27. a=1100;

28.

29.

30. HAL_Init();

31. System_Clock_Init();// SwitchSystem Clock = 80 MHz

32. LED_Init();

33. UART2_Init();

34. ADCx_CLK_ENABLE();

35. ADCx_CHANNEL_GPIO_CLK_ENABLE();

36. DMAx_CHANNELx_CLK_ENABLE();

37. ADCx_FORCE_RESET();

38. ADCx_RELEASE_RESET();

39.

40. b=(float)aResultDMA*3300/4069;

41. while (1){

42. n= sprintf((char *)buffer, "a = %d\t", a);

43. n+= sprintf((char *)buffer +n, "b = %f \r\n", b);

44. USART_Write(USART2,buffer, n);

45. a= a + 1;

46. for (i = 0; i < 8000000; i++); // Delay

47. Red_LED_On();

48.

49. }

50. /* ### - 1 - Initialize ADCperipheral #################################### */

51. AdcHandle.Instance = ADC1;

52. if (HAL_ADC_DeInit(&AdcHandle) != HAL_OK)

53. {

54. /* ADC de-initialization Error */

55. Red_LED_On();

56. }

57.

58. AdcHandle.Init.ClockPrescaler =ADC_CLOCK_ASYNC_DIV1; /* Asynchronous clock mode, inputADC clock not divided */

59. AdcHandle.Init.Resolution =ADC_RESOLUTION_12B; /* 12-bit resolution for converteddata */

60. AdcHandle.Init.DataAlign = ADC_DATAALIGN_RIGHT; /* Right-alignment for converted data */

61. AdcHandle.Init.ScanConvMode = DISABLE; /* Sequencer disabled (ADC conversion ononly 1 channel: channel set on rank 1) */

62. AdcHandle.Init.EOCSelection =ADC_EOC_SINGLE_CONV; /* EOC flag picked-up to indicateconversion end */

63. AdcHandle.Init.LowPowerAutoWait = DISABLE; /* Auto-delayed conversion feature disabled*/

64. AdcHandle.Init.ContinuousConvMode = ENABLE; /* Continuous mode enabled(automatic conversion restart after each conversion) */

65. AdcHandle.Init.NbrOfConversion = 1; /* Parameter discarded becausesequencer is disabled */

66. AdcHandle.Init.DiscontinuousConvMode = DISABLE; /* Parameter discarded because sequencer isdisabled */

67. AdcHandle.Init.NbrOfDiscConversion =1; /* Parameter discarded becausesequencer is disabled */

68. AdcHandle.Init.ExternalTrigConv =ADC_SOFTWARE_START; /* Software start to trigthe 1st conversion manually, without external event */

69. AdcHandle.Init.ExternalTrigConvEdge =ADC_EXTERNALTRIGCONVEDGE_NONE; /* Parameter discarded because software trigger chosen */

70. AdcHandle.Init.DMAContinuousRequests = ENABLE; /* DMA circular mode selected */

71. AdcHandle.Init.Overrun =ADC_OVR_DATA_OVERWRITTEN; /* DR register is overwritten withthe last conversion result in case of overrun */

72. AdcHandle.Init.OversamplingMode = DISABLE; /* No oversampling */

73.

74. /* Initialize ADC peripheral according to the passedparameters */

75. HAL_ADC_Init(&AdcHandle);

76. if (HAL_ADC_Init(&AdcHandle) != HAL_OK)

77. {

78. Red_LED_On();

79. }

80.

81.

82. /* ### - 2 - Start calibration############################################ */

83. HAL_ADCEx_Calibration_Start(&AdcHandle,ADC_SINGLE_ENDED);

84. if (HAL_ADCEx_Calibration_Start(&AdcHandle, ADC_SINGLE_ENDED) != HAL_OK)

85. {

86. Red_LED_On();

87. }

88.

89. /* ### - 3 - Channel configuration######################################## */

90. sConfig.Channel =ADCx_CHANNEL; /* Sampled channel number */

91. sConfig.Rank = ADC_REGULAR_RANK_1; /* Rank of sampled channel numberADCx_CHANNEL */

92. sConfig.SamplingTime = ADC_SAMPLETIME_6CYCLES_5; /* Sampling time (number of clock cycles unit) */

93. sConfig.SingleDiff =ADC_SINGLE_ENDED; /* Single-ended input channel */

94. sConfig.OffsetNumber = ADC_OFFSET_NONE; /* No offset subtraction */

95. sConfig.Offset = 0; /* Parameter discarded becauseoffset correction is disabled */

96. HAL_ADC_ConfigChannel(&AdcHandle,&sConfig);

97. if (HAL_ADC_ConfigChannel(&AdcHandle, &sConfig) != HAL_OK)

98. {

99. Green_LED_Toggle();

100. }

101.

102. /* ### - 4 - Start conversion in DMA mode################################# */

103. HAL_ADC_Start_DMA(&AdcHandle,&aResultDMA, 1);

104. if (HAL_ADC_Start_DMA(&AdcHandle, &aResultDMA, 1) != HAL_OK)

105. {

106. Green_LED_Toggle();

107. }

108.

109.

110. }

adc.c 文件内容：

1. #include "main.h"

3. /** @addtogroupSTM32L4xx_HAL_Examples

4. * @{

5. */

7. /** @defgroup ADC_DMA_Transfer

8. * @{

9. */

10.

11. /* Private typedef-----------------------------------------------------------*/

12. /* Private define------------------------------------------------------------*/

13. /* Private macro -------------------------------------------------------------*/

14. /* Private variables---------------------------------------------------------*/

15. /* Private function prototypes-----------------------------------------------*/

16. /* Private functions---------------------------------------------------------*/

17.

18. /** @defgroup HAL_MSP_Private_Functions

19. * @{

20. */

21.

22. /**

23. * @brief ADC MSP Init

24. * @param hadc : ADC handle

25. * @retval None

26. */

27. void HAL_ADC_MspInit(ADC_HandleTypeDef *hadc)

28. {

29. GPIO_InitTypeDef GPIO_InitStruct;

30. staticDMA_HandleTypeDef DmaHandle;

31.

32. /*##-1- Enable peripheralsand GPIO Clocks #################################*/

33. /* ADC Periph clock enable*/

34. ADCx_CLK_ENABLE();

35. /* ADC Periph interface clockconfiguration */

36. __HAL_RCC_ADC_CONFIG(RCC_ADCCLKSOURCE_SYSCLK);

37. /* Enable DMA clock */

38. DMAx_CHANNELx_CLK_ENABLE();

39.

40. __HAL_RCC_GPIOA_CLK_ENABLE();

41.

42. /*##- 2- Configureperipheral GPIO #########################################*/

43. /* ADC Channel GPIO pinconfiguration */

44. GPIO_InitStruct.Pin =ADCx_CHANNEL_PIN;

45. GPIO_InitStruct.Mode =GPIO_MODE_ANALOG_ADC_CONTROL;

46. GPIO_InitStruct.Pull =GPIO_NOPULL;

47. HAL_GPIO_Init(ADCx_CHANNEL_GPIO_PORT,&GPIO_InitStruct);

48. /*##- 3- Configure DMA#####################################################*/

49.

50. /***********************Configure DMA parameters ***************************/

51. DmaHandle.Instance = DMA1_Channel1;

52. DmaHandle.Init.Request = DMA_REQUEST_0;

53. DmaHandle.Init.Direction = DMA_PERIPH_TO_MEMORY;

54. DmaHandle.Init.PeriphInc = DMA_PINC_DISABLE;

55. DmaHandle.Init.MemInc = DMA_MINC_ENABLE;

56. DmaHandle.Init.PeriphDataAlignment =DMA_PDATAALIGN_WORD;

57. DmaHandle.Init.MemDataAlignment = DMA_MDATAALIGN_WORD;

58. DmaHandle.Init.Mode = DMA_CIRCULAR;

59. DmaHandle.Init.Priority = DMA_PRIORITY_MEDIUM;

60.

61. /* Deinitialize & Initialize the DMA for new transfer */

62. HAL_DMA_DeInit(&DmaHandle);

63. HAL_DMA_Init(&DmaHandle);

64.

65. /* Associate the DMA handle*/

66. __HAL_LINKDMA(hadc,DMA_Handle, DmaHandle);

67.

68. /* NVIC configuration forDMA Input data interrupt */

69. HAL_NVIC_SetPriority(DMA1_Channel1_IRQn, 1,0);

70. HAL_NVIC_EnableIRQ(DMA1_Channel1_IRQn);

71. }

72.

73. /**

74. * @brief ADC MSPDe-Initialization

75. * This function frees the hardwareresources used in this example:

76. * - Disable the Peripheral's clock

77. * - Revert GPIO to their default state

78. * @param hadc: ADC handlepointer

79. * @retval None

80. */

81. void HAL_ADC_MspDeInit(ADC_HandleTypeDef *hadc)

82. {

83.

84. /*##-1- Reset peripherals##################################################*/

85. ADCx_FORCE_RESET();

86. ADCx_RELEASE_RESET();

87. /* ADC Periph clock disable

88. (automatically reset allADC's) */

89. __HAL_RCC_ADC_CLK_DISABLE();

90.

91. /*##-2- Disable peripheralsand GPIO Clocks ################################*/

92. /* De-initialize the ADCChannel GPIO pin */

93. HAL_GPIO_DeInit(ADCx_CHANNEL_GPIO_PORT,ADCx_CHANNEL_PIN);

94. }

95.

96.

97.

98. /**

99. * @brief Initializes the Global MSP.

100. * @param None

101. * @retval None

102. */

赞收藏评论7 发布时间：2018-9-5 17:00

7个回答

wenyangzeng 回答时间：2018-9-5 17:52:47

这个b=(float)aResultDMA*3300/4069;
没有在while()循环里，ADC转换结果aResultDMA在循环里没有赋值给b变量。

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bbbone 回答时间：2018-9-5 18:38:36

本帖最后由 bbbone 于 2018-9-5 18:42 编辑

wenyangzeng 发表于 2018-9-5 17:52
这个b=(float)aResultDMA*3300/4069;
没有在while()循环里，ADC转换结果aResultDMA在循环里没有赋值给b变量 ...

怎么修改呢？我把 b=(float)aResultDMA*3300/4069; 放到while里，依然没起作用啊
老哥

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bbbone 回答时间：2018-9-5 19:00:39

问题出在第四步，main文件的102行。我在第四部后面加一个Green_LED_On,这个灯是不亮的。之前部分都会亮。

/* ### - 4 - Start conversion in DMA mode ################################# */
   HAL_ADC_Start_DMA(&AdcHandle, &aResultDMA, 1);
   if (HAL_ADC_Start_DMA(&AdcHandle, &aResultDMA, 1) != HAL_OK)
   {
   Red_LED_On();
   }
   Green_LED_On();

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wenyangzeng 回答时间：2018-9-5 20:03:59