【MCXA156开发板测评】-5-LPADC中断模式快速配置

慕容雪花 发表于 2025-1-11 23:10

本帖最后由慕容雪花于 2025-1-12 11:11 编辑

上期测评：【MCXA156开发板测评】-4-LPI2C驱动OLED屏幕  <a href="https://bbs.eeworld.com.cn/thread-1304186-1-1.html" target="_blank">https://bbs.eeworld.com.cn/thread-1304186-1-1.html</a>

本次体验使用恩智浦MCUXPRESSO内置的CONFIGTOOL来配置LPADC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：

<ul>
<li>触发ISR（在FWMIE置位的情况下）</li>
<li>或者进行DMA请求（在FWMDE置位的情况下）</li>
</ul>

  

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：

<pre>
<code>/***********************************************************************************************************************
* 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 = {
{
.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 = {
{
.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);
/* Configure trigger 0. */
LPADC_SetConvTriggerConfig(ADC1_PERIPHERAL, 0, &ADC1_triggersConfig);
/* 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);
}</code></pre>

设置转换完成标志位。

<pre>
<code>/* 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
}</code></pre>

在主程序中：

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

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：

<div style="text-align: center;"></div>

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。

页: [1]

电子工程世界-论坛's Archiver

【MCXA156开发板测评】-5-LPADC中断模式快速配置