通過ADC注入通道的使用,可以實時獲取4個GPIO輸入的AD採樣值,下面看具體的代碼。
芯片:STM32F205VCT6
STEP1:初始化GPIO
void GPIO_Configuration ( void )
{
//GPIO -PC0 PC1 PC2 PC3 -ADC3
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init ( GPIOC, &GPIO_InitStructure );
}
STEP2:初始化ADC
void ADC_Configuration(void)
{
ADC_InitTypeDef ADC_InitStructure;
ADC_CommonInitTypeDef ADC_CommonInitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC3, ENABLE);
//ADC Common Init
ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div4;
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_20Cycles;
ADC_CommonInit(&ADC_CommonInitStructure);
// ADC3 Init
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = ENABLE;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 1;
ADC_Init(ADC3, &ADC_InitStructure);
ADC_TempSensorVrefintCmd(ENABLE);
ADC_RegularChannelConfig(ADC3, ADC_Channel_Vrefint, 1, ADC_SampleTime_144Cycles);
ADC_AutoInjectedConvCmd(ADC3, ENABLE);
ADC_ExternalTrigInjectedConvEdgeConfig(ADC3, ADC_ExternalTrigInjecConvEdge_None);
ADC_InjectedSequencerLengthConfig(ADC3, 4);
ADC_InjectedChannelConfig(ADC3, ADC_Channel_10, 3,ADC_SampleTime_144Cycles);
ADC_InjectedChannelConfig(ADC3, ADC_Channel_11, 4,ADC_SampleTime_144Cycles);
ADC_InjectedChannelConfig(ADC3, ADC_Channel_12, 2,ADC_SampleTime_144Cycles);
ADC_InjectedChannelConfig(ADC3, ADC_Channel_13, 1,ADC_SampleTime_144Cycles);
ADC_SetInjectedOffset(ADC3, ADC_InjectedChannel_1, 2000);//採樣後的值減去閾值,可以省去後續的處理
ADC_SetInjectedOffset(ADC3, ADC_InjectedChannel_2, 2000);
// Enable ADC3
ADC_Cmd(ADC3, ENABLE);
ADC_SoftwareStartConv(ADC3);
}
STEP3:使用
value1 = ADC_GetInjectedConversionValue(ADC3, ADC_InjectedChannel_1);
value2 = ADC_GetInjectedConversionValue(ADC3, ADC_InjectedChannel_2);
value3 = ADC_GetInjectedConversionValue(ADC3, ADC_InjectedChannel_3);
value4 = ADC_GetInjectedConversionValue(ADC3, ADC_InjectedChannel_4);