Question
ADC_GetConversionValue(ADC) == 0 ??
Posted on February 06, 2014 at 21:35
Hi I'm getting sometimes 0 from my ADC conversation but this can't be possible.
Pls correct me pls if I say something wrong. I'm working with the STM3210E-Eval board it has an STM32F103GT processor. This is my configuration for my adc1 , I have 3 ADC's because it is the same I'm just posting one.
void
Config_ADC(GPIO_InitTypeDef *GPIO_InitStructure)
{
RCC_ADCCLKConfig(RCC_PCLK2_Div6);
//clock for ADC ADCCLK = PCLK2/6 = 72/6 = 12MHz*/
// enable ADC system clock
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO | RCC_APB2Periph_ADC1 | RCC_APB2Periph_ADC2 | RCC_APB2Periph_ADC3, ENABLE);
/* Configure PC.01, PC.02 and PC.03 (ADC Channel 11, ADC Channel 12, ADC Channel 13) as analog input */
GPIO_InitStructure->GPIO_Pin = GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3 ;
// PC.01, PC.02 and PC.03
GPIO_InitStructure->GPIO_Mode = GPIO_Mode_AIN;
// Input-Mode
GPIO_InitStructure->GPIO_Speed = GPIO_Speed_50MHz;
// Speed of port
GPIO_Init(GPIOC, GPIO_InitStructure);
// apply configuration on PortC
}
ADC_InitStructure->ADC_ContinuousConvMode = ENABLE;
//ster next convert automatically
ADC_InitStructure->ADC_DataAlign = ADC_DataAlign_Right;
//put left/right adjusted in register
ADC_InitStructure->ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
//choose which extern signal should start convert
ADC_InitStructure->ADC_Mode = ADC_Mode_Independent;
ADC_InitStructure->ADC_NbrOfChannel = 1;
ADC_InitStructure->ADC_ScanConvMode = DISABLE;
ADC_RegularChannelConfig(ADC1, ADC_Channel_11, 1, ADC_SampleTime_28Cycles5);
ADC_Init(ADC1, ADC_InitStructure);
//set config of ADC1
ADC_Cmd(ADC1, ENABLE);
1.
//start-callibration
2.
ADC_ResetCalibration(ADC1);
/* Enable ADC1 reset calibration register */
3.
while
(ADC_GetResetCalibrationStatus(ADC1));
/* Check the end of ADC1 reset calibration register (Reset previous calibration)*/
4.
ADC_StartCalibration(ADC1);
/* Start ADC1 calibration */
5.
while
(ADC_GetCalibrationStatus(ADC1));
/* Check the end of ADC1 calibration */
6.
//End-callibration
7.
8.
ADC_SoftwareStartConvCmd(ADC1, ENABLE);
void
Config_Timer_TIM2(TIM_TimeBaseInitTypeDef *TIM_TimeBaseStructure, NVIC_InitTypeDef *NVIC_InitStructure)
{
// enable TIMER TIM2 system clock
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
/* Enable the Timer2 Interrupt */
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);
NVIC_InitStructure->NVIC_IRQChannel = TIM2_IRQn;
// configure the Timer2 interrupts
NVIC_InitStructure->NVIC_IRQChannelPreemptionPriority = 3;
// sets the priority group of the TIMER2 interrupts
NVIC_InitStructure->NVIC_IRQChannelSubPriority = 0;
// set the subpriority inside the group
NVIC_InitStructure->NVIC_IRQChannelCmd = ENABLE;
// TIMER2 interrupts are globally enabled
NVIC_Init(NVIC_InitStructure);
/* Configure Timer which is every 1 ms active*/
TIM_DeInit(TIM2);
TIM_TimeBaseStructInit(TIM_TimeBaseStructure);
/* Time base configuration */
TIM_TimeBaseStructure->TIM_Prescaler = 72 - 1;
// 72 MHz / 72 = 1 Mhz
TIM_TimeBaseStructure->TIM_Period = 30 - 1;
// (1/1Mhz) * 30 = 30 us;
TIM_TimeBaseStructure->TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure->TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, TIM_TimeBaseStructure);
/* Enable TIM2 Update Interrupt */
TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
/* Enable TIM2 */
TIM_Cmd(TIM2,ENABLE);
}
void
TIM2_IRQHandler(
void
)
{
if
(TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)
{
if
(calibration < calibration_counter)
{
array1 =ADC_GetConversionValue(ADC1);
array2 =ADC_GetConversionValue(ADC2);
array3 =ADC_GetConversionValue(ADC3);
TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
//Update Interrupt
}
}
}