adc.c

STM32综合例程（3.5.0固件库）

#include "stm32f10x.h"
#include <stdio.h>
#include "adc.h"

#define SAMP_COUNT	20	/* 样本个数，表示200ms内的采样数据求平均值 */

uint16_t g_AdcValue;	/* ADC 采样值 */

void ADC_Configuration(void);
uint16_t GetADC(void);
void AdcPro(void);

void ADC_Configuration(void)
{
	GPIO_InitTypeDef GPIO_InitStructure;
	ADC_InitTypeDef ADC_InitStructure;
	__IO uint16_t ADCConvertedValue;

    /* 使能 ADC1 and GPIOC clock */
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 | RCC_APB2Periph_GPIOC, ENABLE);

	/* 配置PC4为模拟输入(ADC Channel14) */
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
	GPIO_Init(GPIOC, &GPIO_InitStructure);

	/* 配置ADC1, 不用DMA, 用软件自己触发 */
	ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
	ADC_InitStructure.ADC_ScanConvMode = ENABLE;
	ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
	ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
	ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
	ADC_InitStructure.ADC_NbrOfChannel = 1;
	ADC_Init(ADC1, &ADC_InitStructure);

	/* ADC1 regular channel14 configuration */
	ADC_RegularChannelConfig(ADC1, ADC_Channel_14, 1, ADC_SampleTime_55Cycles5);

	/* Enable ADC1 DMA */
	ADC_DMACmd(ADC1, ENABLE);

	/* Enable ADC1 */
	ADC_Cmd(ADC1, ENABLE);

	/* Enable ADC1 reset calibaration register */
	ADC_ResetCalibration(ADC1);
	/* Check the end of ADC1 reset calibration register */
	while(ADC_GetResetCalibrationStatus(ADC1));

	/* Start ADC1 calibaration */
	ADC_StartCalibration(ADC1);
	/* Check the end of ADC1 calibration */
	while(ADC_GetCalibrationStatus(ADC1));

	/* Start ADC1 Software Conversion */
	ADC_SoftwareStartConvCmd(ADC1, ENABLE);
}

void AdcPro(void)
{
	static uint16_t buf[SAMP_COUNT];
	static uint8_t write;
	uint32_t sum;
	uint8_t i;

	buf[write] = ADC_GetConversionValue(ADC1);
	if (++write >= SAMP_COUNT)
	{
		write = 0;
	}

	/* 下面这段代码采用求平均值的方法进行滤波
		也可以改善下，选择去掉最大和最下2个值，是数据更加精确
	*/
	sum = 0;
	for (i = 0; i < SAMP_COUNT; i++)
	{
		sum += buf[i];
	}
	g_AdcValue = sum / SAMP_COUNT;	/* ADC采样值由若干次采样值平均 */

	ADC_SoftwareStartConvCmd(ADC1, ENABLE);	/* 软件启动下次ADC转换 */
}

uint16_t GetADC(void)
{
	uint16_t ret;

	/* 进行临界区保护，关闭中断 */
	__set_PRIMASK(1);  /* 关中断 */

	ret = g_AdcValue;

	__set_PRIMASK(0);  /* 开中断 */

	return ret;
}