Posted on June 02, 2014 at 19:41
Hi every body,
I am using stm32f0 to control a water control systems by getting a value from a temperature sensor which is read by the ADC.
I am trying to activate my system 15 secondes each 30 secondes, 4 times ,and after that wait 30 secondes.
Since i wanted to test this system, my problem is that when i wire to the ground the pin which is supposed to be attached to the sensor's output while the system is working , it do the cycle again as if the adc is reading a value highly above zero.
what i mean is that when the processor is executing the second loop and that i wire PA1 to ground, it executes the loop again.
Can anybody help me please?
Thank you for your attention .
Here is my code:
#include ''stm32f0xx.h''
#include<stm32f0xx_gpio.h>
#include<stm32f0xx_rcc.h>
#include<stm32f0xx_pwr.h>
#include<stm32f0xx_adc.h>
GPIO_InitTypeDef GPIO_InitStructure;
ADC_InitTypeDef ADC_InitStruct ;
void
AdcConfiguration(){
ADC_InitStruct.ADC_Resolution = ADC_Resolution_12b;
/* Initialize the ADC_ContinuousConvMode member */
ADC_InitStruct.ADC_ContinuousConvMode = ENABLE;
/* Initialize the ADC_ExternalTrigConvEdge member */
ADC_InitStruct.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
/* Initialize the ADC_ExternalTrigConv member */
ADC_InitStruct.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_TRGO;
/* Initialize the ADC_DataAlign member */
ADC_InitStruct.ADC_DataAlign = ADC_DataAlign_Right;
/* Initialize the ADC_ScanDirection member */
ADC_InitStruct.ADC_ScanDirection = ADC_ScanDirection_Upward ;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1 ;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_Level_1;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
GPIO_Init(GPIOA, &GPIO_InitStructure);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
ADC_Init(ADC1,&ADC_InitStruct);
ADC_ChannelConfig( ADC1,ADC_Channel_1, ADC_SampleTime_239_5Cycles);
ADC_Cmd(ADC1, ENABLE);
ADC_StartOfConversion(ADC1);
}
void
InitPinX(uint32_t GPIO_Pin_X,GPIO_TypeDef* GPIOx)
{
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_X ;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_Level_1;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOx, &GPIO_InitStructure);
}
void
delay()
{
long
j=0;
while
(j<50000000)
// delay 15 secondes
{
j++;
}
}
void
main(
void
)
{
int
arr=0;
uint16_t value=0;
float
temp=0;
AdcConfiguration();
InitPinX(GPIO_Pin_8,GPIOA);
GPIO_ResetBits( GPIOA,GPIO_Pin_8);
while
(1)
{ADC_StartOfConversion(ADC1);
value=ADC_GetConversionValue(ADC1);
temp=100*(value*3.3/4096+0.015);
if
(temp>20)
{
while
(arr !=4){
GPIO_SetBits( GPIOA,GPIO_Pin_8);
delay();
arr=arr+1;
GPIO_ResetBits( GPIOA,GPIO_Pin_8);
delay();
}
arr=0;
ADC_StopOfConversion(ADC1);
delay();
delay();
value=0;
}
}
#ifdef USE_FULL_ASSERT
void
assert_failed(uint8_t* file, uint32_t line)
{
while
(1)
{
}
}
void
PWR_BackupAccessCmd(FunctionalState NewState)
{
/* Check the parameters */
assert_param(IS_FUNCTIONAL_STATE(NewState));
if
(NewState != DISABLE)
{
/* Enable the Backup Domain Access */
PWR->CR |= PWR_CR_DBP;
}
else
{
/* Disable the Backup Domain Access */
PWR->CR &= (uint32_t)~((uint32_t)PWR_CR_DBP);
}
}
