Hi,
For ADC measurement, there is two ways : continous conversion mode that needs DMA, and single conversion mode.
With the second solution, you have to configure and calibrate the ADC, and then to launch a conversion when needed, while with the first solution, the DMA updates automatically the memory with the converted value.
For the DMA solution, you can take a look to the "ADC1_DMA" example from the ST library examples.
Foth the single conversion solution, you can find hereafter a program example for the extension Primer "Cx_ADC1" signal acquisition.
Initialization :
/*******************************************************************************
* Function Name : ADConverter_Init
* Description : Initialize ADC for measuring.
* Input : None.
* Output : None.
* Return : None.
*******************************************************************************/
void ADConverter_Init( void )
{
ADC_InitTypeDef ADC_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
// Enable PORT clock
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
/* Configure pin as analog input ---------------*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_14;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
GPIO_Init(GPIO_C, &GPIO_InitStructure);
/* Enable ADC1 clock */
RCC_APB2PeriphClockCmd( RCC_APB2Periph_ADC1, 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_None;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfChannel = 1;
ADC_Init( ADC1, &ADC_InitStructure );
/* ADC1 Regular Channel 14 */
ADC_RegularChannelConfig( ADC1, ADC_Channel_14, 1, ADC_SampleTime_239Cycles5);
/* Enable ADC1 external trigger conversion */
ADC_ExternalTrigConvCmd( ADC1, ENABLE );
/* Enable ADC1 */
ADC_Cmd(ADC1, ENABLE);
/* Enable ADC1 reset calibaration register */
ADC_ResetCalibration(ADC1);
/* Check the end of ADC1 reset calibration register */
while(ADC_GetResetCalibrationStatus(ADC1));
/* Start ADC1 calibaration */
ADC_StartCalibration(ADC1);
/* Check the end of ADC1 calibration */
while(ADC_GetCalibrationStatus(ADC1));
}
Acquisition :
/*******************************************************************************
* Function Name : Get_Measure
* Description : Get the ADC value.
* Input : None.
* Output : Value in points from 0 to 4096.
* Return : None.
*******************************************************************************/
u16 Get_Measure()
{
// Start ADC1 Software Conversion
ADC_SoftwareStartConvCmd( ADC1, ENABLE );
// Wait for end of conversion
while (ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC) == RESET);
// Return the conversion value
return (ADC_GetConversionValue(ADC1));
}
Yves
Last edited by yrt (2009-11-23 08:04:24)
