Posted on March 11, 2014 at 16:50Hello everybody,
I'am trying to use analog watchdog on STM32F051K4 and I face some problems.
I want to measure a pulse on PA0 (ADC_IN0) of 100us wide with an 1V amplitude above 0.5V offset. There is no example on this function for the F0. I tried to adapt F1 example without success yet.
Here is the relevant code:
//threshold values for watchdog
#define ADC_THR_H 0x708 //1V
#define ADC_THR_L 0x5DC //0.88V
/* GPIOB GPIO A Periph clock enable */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB | RCC_AHBPeriph_GPIOA, ENABLE);
/* ADC1 Periph clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
/*configure PA0 for ADC input*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/*Enable interrupt on ADC Analog watchdog*/
NVIC_InitStructure.NVIC_IRQChannel = ADC1_COMP_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
ADC_ClearITPendingBit(ADC1,ADC_IT_AWD);
ADC_ITConfig(ADC1, ADC_IT_AWD, ENABLE);
* Initialize ADC defaults */
/* ADC1 Configuration *******************************************************/
/* ADCs DeInit */
ADC_DeInit(ADC1);
/* Configure the ADC1 with analog watchdog*/
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
ADC_InitStructure.ADC_ExternalTrigConv = ADC_AnalogWatchdog_Channel_0;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
//ADC_InitStructure.ADC_ScanDirection = ADC_ScanDirection_Upward;
//ADC_ChannelConfig(ADC1,ADC_Channel_0,ADC_SampleTime_1_5Cycles);
ADC_Init(ADC1, &ADC_InitStructure);
//Configure analog watchdog
ADC_AnalogWatchdogSingleChannelConfig(ADC1, ADC_Channel_0);
ADC_AnalogWatchdogThresholdsConfig(ADC1,ADC_THR_H,ADC_THR_L);
ADC_AnalogWatchdogCmd(ADC1,ENABLE);
ADC_AnalogWatchdogSingleChannelCmd(ADC1,ENABLE);
ADC_StartOfConversion(ADC1);
ADC_Cmd(ADC1,ENABLE);
/*and my interrupt routine:*/
void ADC1_COMP_IRQHandler(void)
{
if (ADC_GetITStatus(ADC1, ADC_IT_AWD))
{
ADC_ClearFlag(ADC1, ADC_FLAG_AWD);
ADC_ClearITPendingBit(ADC1, ADC_IT_AWD);
if(ADC_threshold==0) ADC_threshold=1;
}
}
In my main program, I check ADC_threshold value to light a led and I reset it.
If somebody could help me, thanks.
