【MCXA156开发板测评】-5-LPI2C中断模式快速配置

慕容雪花

【MCXA156开发板测评】-5-LPI2C中断模式快速配置 [复制链接]

本帖最后由慕容雪花于 2025-1-11 23:37 编辑

上期测评：【MCXA156开发板测评】-4-LPI2C驱动OLED屏幕 https://bbs.eeworld.com.cn/thread-1304186-1-1.html

本次体验使用恩智浦MCUXPRESSO内置的CONFIGTOOL来配置LPI2C3的中断模式。LPADC的FIFO Control Register (FCTRL0)可以设置“Watermark Level Selection”。

当ADC转换结果数量大于设置的阈值FIFO 0 watermark后：

触发ISR（在FWMIE置位的情况下）
或者进行DMA请求（在FWMDE置位的情况下）

在IRQ服务程序中可以设置一个转换完成标志，方便在主程序中获取转换结果。

一、CONFIGTOOL配置

设置FIFO0WATERMARK为0：

选择中断源，并使能中断向量。

二、代码适配

初始化代码：

/***********************************************************************************************************************
 * ADC1 initialization code
 **********************************************************************************************************************/
/* clang-format off */
/* TEXT BELOW IS USED AS SETTING FOR TOOLS *************************************
instance:
- name: 'ADC1'
- type: 'lpadc'
- mode: 'LPADC'
- custom_name_enabled: 'false'
- type_id: 'lpadc_2.8.1'
- functional_group: 'BOARD_InitPeripherals'
- peripheral: 'ADC1'
- config_sets:
  - fsl_lpadc:
    - lpadcConfig:
      - clockSource: 'AsynchronousFunctionClock'
      - clockSourceFreq: 'ClocksTool_DefaultInit'
      - enableInDozeMode: 'false'
      - conversionAverageMode: 'kLPADC_ConversionAverage8'
      - offsetCalibration: 'no'
      - autoCalibrate: 'true'
      - enableAnalogPreliminary: 'true'
      - powerUpDelay: '0x80'
      - referenceVoltageSource: 'kLPADC_ReferenceVoltageAlt3'
      - powerLevelMode: 'kLPADC_PowerLevelAlt4'
      - triggerPriorityPolicy: 'kLPADC_ConvPreemptImmediatelyNotAutoResumed'
      - enableConvPause: 'false'
      - convPauseDelay: '0'
      - FIFOWatermark: '0'
      - FIFOWatermarkDMA: 'false'
    - lpadcConvCommandConfig:
      - 0:
        - user_commandId: ''
        - commandId: '1'
        - chainedNextCommandNumber: '0'
        - sampleChannelMode: 'kLPADC_SampleChannelSingleEndSideA'
        - channelNumber: 'A.21'
        - enableAutoChannelIncrement: 'false'
        - loopCount: '0'
        - hardwareAverageMode: 'kLPADC_HardwareAverageCount1'
        - sampleTimeMode: 'kLPADC_SampleTimeADCK3'
        - hardwareCompareMode: 'kLPADC_HardwareCompareDisabled'
        - hardwareCompareValueHigh: '0'
        - hardwareCompareValueLow: '0'
        - conversionResoultuionMode: 'kLPADC_ConversionResolutionHigh'
        - enableWaitTrigger: 'false'
    - lpadcConvTriggerConfig:
      - 0:
        - user_triggerId: ''
        - triggerId: '0'
        - targetCommandId: '1'
        - delayPower: '0'
        - priority: 'false'
        - enableHardwareTrigger: 'false'
    - IRQ_cfg:
      - interrupt_type: 'kLPADC_FIFO0WatermarkInterruptEnable'
      - enable_irq: 'true'
      - adc_interrupt:
        - IRQn: 'ADC1_IRQn'
        - enable_interrrupt: 'enabled'
        - enable_priority: 'true'
        - priority: '0'
        - enable_custom_name: 'false'
 * BE CAREFUL MODIFYING THIS COMMENT - IT IS YAML SETTINGS FOR TOOLS **********/
/* clang-format on */
const lpadc_config_t ADC1_config = {
  .enableInDozeMode = false,
  .conversionAverageMode = kLPADC_ConversionAverage8,
  .enableAnalogPreliminary = true,
  .powerUpDelay = 0x80UL,
  .referenceVoltageSource = kLPADC_ReferenceVoltageAlt3,
  .powerLevelMode = kLPADC_PowerLevelAlt4,
  .triggerPriorityPolicy = kLPADC_ConvPreemptImmediatelyNotAutoResumed,
  .enableConvPause = false,
  .convPauseDelay = 0UL,
  .FIFOWatermark = 0UL,
};
lpadc_conv_command_config_t ADC1_commandsConfig[1] = {
  {
    .sampleChannelMode = kLPADC_SampleChannelSingleEndSideA,
    .channelNumber = 21U,
    .chainedNextCommandNumber = 0,
    .enableAutoChannelIncrement = false,
    .loopCount = 0UL,
    .hardwareAverageMode = kLPADC_HardwareAverageCount1,
    .sampleTimeMode = kLPADC_SampleTimeADCK3,
    .hardwareCompareMode = kLPADC_HardwareCompareDisabled,
    .hardwareCompareValueHigh = 0UL,
    .hardwareCompareValueLow = 0UL,
    .conversionResolutionMode = kLPADC_ConversionResolutionHigh,
    .enableWaitTrigger = false
  }
};
lpadc_conv_trigger_config_t ADC1_triggersConfig[1] = {
  {
    .targetCommandId = 1,
    .delayPower = 0UL,
    .priority = 1,
    .enableHardwareTrigger = false
  }
};

static void ADC1_init(void) {
  /* Initialize LPADC converter */
  LPADC_Init(ADC1_PERIPHERAL, &ADC1_config);
  /* Perform auto calibration */
  LPADC_DoAutoCalibration(ADC1_PERIPHERAL);
  /* Configure conversion command 1. */
  LPADC_SetConvCommandConfig(ADC1_PERIPHERAL, 1, &ADC1_commandsConfig[0]);
  /* Configure trigger 0. */
  LPADC_SetConvTriggerConfig(ADC1_PERIPHERAL, 0, &ADC1_triggersConfig[0]);
  /* Interrupt vector ADC1_IRQn priority settings in the NVIC. */
  NVIC_SetPriority(ADC1_IRQN, ADC1_IRQ_PRIORITY);
  /* Enable interrupts from LPADC */
  LPADC_EnableInterrupts(ADC1_PERIPHERAL, (kLPADC_FIFO0WatermarkInterruptEnable));
  /* Enable interrupt ADC1_IRQN request in the NVIC */
  EnableIRQ(ADC1_IRQN);
}

设置转换完成标志位。

/* ADC1_IRQn interrupt handler */
void ADC1_IRQHANDLER(void) {
  /* Place your code here */
  if (LPADC_GetConvResult(ADC1_PERIPHERAL, &mLpadcResultConfigStruct))
  {
	  g_LpadcConversionCompletedFlag = true;
  }

  #if defined __CORTEX_M && (__CORTEX_M == 4U)
    __DSB();
  #endif
}

在主程序中：

        if(g_LpadcConversionCompletedFlag)
        {
        	PRINTF("%d\r\n", ((mLpadcResultConfigStruct.convValue)));
        	g_LpadcConversionCompletedFlag = false;
        }

三、实物测试

MIKROBUS P3_30（功能：LPADC1_A21）引脚接入模拟声音传感器。

传感器型号：DFROBOT SEN0487。

这是一款超小体积的MEMS麦克风。放大器增益为66，当没有检测到声音时，输出电压在1.5V左右浮动，在说话时通过ADC采样可以很容易看到声音的波形。兼容3.3V/5V，可以很轻松的用在各类主控上。引脚说明：

串口输出采集到的声音传感器数据并发送到上位机：

四、总结

使用恩智浦MCUXPRESSO以及MCUCONFIGTOOL非常方便的配置LPADC的各种工作模式与参数，自动化生成代码节省了大量的时间，方便快速上述ADC模块。当然LPADC还有低功耗模式等多个特点有待探索。