External interrupt for trigger ADC

hamed_solar · ‎2016-07-07

Posted on July 07, 2016 at 10:38

Hi

I use EXTI for trigger ADC for stm32f

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
/* DMA1 Channel1 Configuration ----------------------------------------------*/
DMA_DeInit(DMA1_Channel1);
DMA_InitStructure.DMA_PeripheralBaseAddr = ADC1_DR_Address;
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&ADC3ConvertedValue;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_BufferSize = 300;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel1, &DMA_InitStructure);
/* Enable DMA Stream Half / Transfer Complete interrupt */
//DMA_ITConfig(DMA1_Channel1, DMA_IT_TC | DMA_IT_HT, ENABLE);
/* Enable DMA1 channel1 */
DMA_Cmd(DMA1_Channel1, ENABLE);
//////////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////////////////////
/* ADC1 configuration ------------------------------------------------------*/
ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_InitStructure.ADC_ScanConvMode = DISABLE;
ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
ADC_InitStructure.ADC_ExternalTrigConv =ADC_ExternalTrigConv_Ext_IT11_TIM8_TRGO ;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfChannel = 1;
ADC_Init(ADC1, &ADC_InitStructure);
//////////////////////////////////////////////////////////////////////////////////////////////////
 ADC_RegularChannelConfig(ADC1, ADC_Channel_12, 1, ADC_SampleTime_1Cycles5); //c2 ==for voltage /* Regular discontinuous mode channel number configuration */
 ADC_DiscModeChannelCountConfig(ADC1, 1);
 /* Enable regular discontinuous mode */
 ADC_DiscModeCmd(ADC1, ENABLE);
 /* Enable ADC1 external trigger conversion */ 
 ADC_ExternalTrigConvCmd(ADC1, ENABLE);
 
 /* Enable ADC1 DMA */
 ADC_DMACmd(ADC1, ENABLE);
 
 
 /* Enable ADC1 */
 ADC_Cmd(ADC1, ENABLE);
 /* Enable ADC1 reset calibration register */ 
 ADC_ResetCalibration(ADC1);
 /* Check the end of ADC1 reset calibration register */
 while(ADC_GetResetCalibrationStatus(ADC1));
 /* Start ADC1 calibration */
 ADC_StartCalibration(ADC1);
 /* Check the end of ADC1 calibration */
 while(ADC_GetCalibrationStatus(ADC1));

//////////////////////////////////////////////////////////////////////////////////////////////////

The below code is for configuring EXTI.

void EXTI11_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/* Enable GPIOA clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
/* Configure PA.00 pin as input floating */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* Enable AFIO clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
/* Connect EXTI0 Line to PB.11 pin */
GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource11);
/* Configure EXTI0 line */
EXTI_InitStructure.EXTI_Line = EXTI_Line11;
EXTI_InitStructure.EXTI_Mode =EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling; 
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
// /* Enable and set EXTI0 Interrupt to the lowest priority */
NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}

It works. When I connect the

EXTI_Line11

to the square wave the ADC convert the analog input and put them into the ADC3ConvertedValue. I adjust EXTI for rising and falling edge. I want to calculate data between two rising and falling edge of the external interrupt . But I dont know which section of the ADC3ConvertedValue is linked to the time of converting between two rising and falling edge of external interrupt?

Regards

waclawek.jan · ‎2016-07-07

Posted on July 08, 2016 at 00:15

What exactly do you want to measure? The maximum/peak of the triangular waveform? You might perhaps want to build an (analogue) peak detector (basically a diode and a capacitor) and measure the voltage on that, perhaps at the falling edge; you can also discharge the capacitor actively after the voltage is measured. To work out the details is upon you though.

JW