【MCXN947开发板测评】A/D数据采集与应用

jennyzhaojie

【MCXN947开发板测评】A/D数据采集与应用 [复制链接]

MCXN947配有 2个16位 ADC，用它可以实现高精度的模拟量数据采集。

对A/D数据采集功能的采集结果如图1所示，所输入的模拟信号由 J8接口的28号引脚 (ADC0_A2)输入。

在完成一次数据采集后，需在发送一个字符后才能获得一个新的数据采集值。

 

图1 随机采集

 

 

图2 极值采集

 

此外，在进行数值变换的情况下，还可得到检测的电压值，见图3所示。

 

图3 显示电压值

 

在按图4进行连接的情况下，实现数据检测与显示的主程序是：

int main(void)
{
    lpadc_config_t mLpadcConfigStruct;
    lpadc_conv_trigger_config_t mLpadcTriggerConfigStruct;
    lpadc_conv_command_config_t mLpadcCommandConfigStruct;
    lpadc_conv_result_t mLpadcResultConfigStruct;
    vref_config_t vrefConfig;
    CLOCK_SetClkDiv(kCLOCK_DivFlexcom4Clk, 1U);
    CLOCK_AttachClk(BOARD_DEBUG_UART_CLK_ATTACH);
    CLOCK_SetClkDiv(kCLOCK_DivAdc0Clk, 1U);
    CLOCK_AttachClk(kFRO_HF_to_ADC0);
    SPC_EnableActiveModeAnalogModules(DEMO_SPC_BASE, kSPC_controlVref);
    VREF_GetDefaultConfig(&vrefConfig);
    vrefConfig.bufferMode = kVREF_ModeBandgapOnly;
    VREF_Init(DEMO_VREF_BASE, &vrefConfig);
    BOARD_InitPins();
    BOARD_InitBootClocks();
    BOARD_InitDebugConsole();
Lcd_config();
	Lcd_Init();
    LCD_Clear(RED);
    LCD_ShowString(20,10,"MCXN947",YELLOW);  
    LCD_ShowString(20,30,"A/D Test",YELLOW);
	LCD_ShowString(20,50,"ADC=",YELLOW);
    LPADC_GetDefaultConfig(&mLpadcConfigStruct);
    mLpadcConfigStruct.enableAnalogPreliminary = true;
#if defined(DEMO_LPADC_VREF_SOURCE)
    mLpadcConfigStruct.referenceVoltageSource = DEMO_LPADC_VREF_SOURCE;
#endif 
#if defined(FSL_FEATURE_LPADC_HAS_CTRL_CAL_AVGS) && FSL_FEATURE_LPADC_HAS_CTRL_CAL_AVGS
    mLpadcConfigStruct.conversionAverageMode = kLPADC_ConversionAverage128;
#endif 
    LPADC_Init(DEMO_LPADC_BASE, &mLpadcConfigStruct);
#if defined(FSL_FEATURE_LPADC_HAS_CTRL_CALOFSMODE) && FSL_FEATURE_LPADC_HAS_CTRL_CALOFSMODE
    LPADC_SetOffsetCalibrationMode(DEMO_LPADC_BASE, DEMO_LPADC_OFFSET_CALIBRATION_MODE);
#endif #if defined(FSL_FEATURE_LPADC_HAS_CTRL_CALOFS) && FSL_FEATURE_LPADC_HAS_CTRL_CALOFS
#if defined(DEMO_LPADC_DO_OFFSET_CALIBRATION) && DEMO_LPADC_DO_OFFSET_CALIBRATION
LPADC_DoOffsetCalibration(DEMO_LPADC_BASE);
#else 
#if defined(FSL_FEATURE_LPADC_HAS_OFSTRIM) && FSL_FEATURE_LPADC_HAS_OFSTRIM
#if defined(FSL_FEATURE_LPADC_OFSTRIM_COUNT) && (FSL_FEATURE_LPADC_OFSTRIM_COUNT == 2U)
    LPADC_SetOffsetValue(DEMO_LPADC_BASE,DEMO_LPADC_OFFSET_VALUE_A, DEMO_LPADC_OFFSET_VALUE_B);
#elif defined(FSL_FEATURE_LPADC_OFSTRIM_COUNT) && (FSL_FEATURE_LPADC_OFSTRIM_COUNT == 1U)
    LPADC_SetOffsetValue(DEMO_LPADC_BASE, DEMO_LPADC_OFFSET_VALUE);
#endif 
#else
    if (DEMO_LPADC_OFFSET_CALIBRATION_MODE == kLPADC_OffsetCalibration12bitMode)
    {
        LPADC_SetOffset12BitValue(DEMO_LPADC_BASE,DEMO_LPADC_OFFSET_VALUE_A, DEMO_LPADC_OFFSET_VALUE_B);
    }
    else
    {
        LPADC_SetOffset16BitValue(DEMO_LPADC_BASE,DEMO_LPADC_OFFSET_VALUE_A, DEMO_LPADC_OFFSET_VALUE_B);
    }
#endif 
#endif 
#endif
#if defined(FSL_FEATURE_LPADC_HAS_CTRL_CAL_REQ) && FSL_FEATURE_LPADC_HAS_CTRL_CAL_REQ
    LPADC_DoAutoCalibration(DEMO_LPADC_BASE);
#endif 
#if (defined(FSL_FEATURE_LPADC_HAS_CFG_CALOFS) && FSL_FEATURE_LPADC_HAS_CFG_CALOFS)
    LPADC_DoAutoCalibration(DEMO_LPADC_BASE);
#endif 
    LPADC_GetDefaultConvCommandConfig(&mLpadcCommandConfigStruct);
    mLpadcCommandConfigStruct.channelNumber = DEMO_LPADC_USER_CHANNEL;
#if defined(DEMO_LPADC_USE_HIGH_RESOLUTION) && DEMO_LPADC_USE_HIGH_RESOLUTION
    mLpadcCommandConfigStruct.conversionResolutionMode = kLPADC_ConversionResolutionHigh;
#endif 
    LPADC_SetConvCommandConfig(DEMO_LPADC_BASE,DEMO_LPADC_USER_CMDID, &mLpadcCommandConfigStruct);
    LPADC_GetDefaultConvTriggerConfig(&mLpadcTriggerConfigStruct);
    mLpadcTriggerConfigStruct.targetCommandId       = DEMO_LPADC_USER_CMDID;
    mLpadcTriggerConfigStruct.enableHardwareTrigger = false;
LPADC_SetConvTriggerConfig(DEMO_LPADC_BASE, 0U, &mLpadcTriggerConfigStruct);
#if defined(FSL_FEATURE_LPADC_HAS_CMDL_CSCALE) && FSL_FEATURE_LPADC_HAS_CMDL_CSCALE
    if (kLPADC_SampleFullScale == mLpadcCommandConfigStruct.sampleScaleMode)
    {
        PRINTF("Full channel scale (Factor of 1).\r\n");
    }
    else if (kLPADC_SamplePartScale == mLpadcCommandConfigStruct.sampleScaleMode)
    {
        PRINTF("Divided input voltage signal. (Factor of 30/64).\r\n");
    }
#endif
    while (1)
    {
        LPADC_DoSoftwareTrigger(DEMO_LPADC_BASE, 1U); #if (defined(FSL_FEATURE_LPADC_FIFO_COUNT) && (FSL_FEATURE_LPADC_FIFO_COUNT == 2U))
        while (!LPADC_GetConvResult(DEMO_LPADC_BASE, &mLpadcResultConfigStruct, 0U))
#else
        while (!LPADC_GetConvResult(DEMO_LPADC_BASE, &mLpadcResultConfigStruct))
#endif 
		LCD_ShowNum(52,50,((mLpadcResultConfigStruct.convValue) >> g_LpadcResultShift),4,YELLOW);
		delay();
    }
}

 

经程序的编译和下载，其显示效果如图5所示。

 

图4 电路连接

 

 

图5 显示效果