Posted on May 03, 2015 at 16:46Hello,
I'm working on custom board using STM32L152 chip.
Vref is : 3.19V
When i injuct to the analog pin 2.7 i read 4019 ,while 0 represent as 650.
(It seemed like 650 is the gap ????)
below my initialize ADC code :
/////////////////////////////////////////////
RCC_HSICmd(ENABLE);
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOC, ENABLE);
// Configuration CURRENT_SNS pins
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a_opAdcControl->m_oAdcGpioControl.GPIO_Pin = GPIO_Pin_1;
a_opAdcControl->m_oAdcGpioControl.GPIO_Mode = GPIO_Mode_AN;
GPIO_Init(GPIOC, &a_opAdcControl->m_oAdcGpioControl);
// Configuration Battary test
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
// a_opAdcControl->m_oAdcGpioControl.GPIO_Pin = GPIO_Pin_4;
// a_opAdcControl->m_oAdcGpioControl.GPIO_Mode = GPIO_Mode_AN;
// GPIO_Init(GPIOA, &a_opAdcControl->m_oAdcGpioControl);
// Check that HSI oscillator is ready
while(RCC_GetFlagStatus(RCC_FLAG_HSIRDY) == RESET);
// ADC1 Configuration ------------------------------------------------------
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
// ADC1 DeInit
ADC_DeInit(ADC1);
// ADC1 Configuration
a_opAdcControl->m_oAdcInitControl.ADC_Resolution = ADC_Resolution_12b;
a_opAdcControl->m_oAdcInitControl.ADC_ScanConvMode = DISABLE;// Disable multichannels
a_opAdcControl->m_oAdcInitControl.ADC_ContinuousConvMode = DISABLE;// One Conversion at a time
a_opAdcControl->m_oAdcInitControl.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;//ADC_ExternalTrigConvEdge_Rising;//ADC_ExternalTrigConvEdge_Falling;
a_opAdcControl->m_oAdcInitControl.ADC_ExternalTrigConv =0;
a_opAdcControl->m_oAdcInitControl.ADC_DataAlign = ADC_DataAlign_Right;
a_opAdcControl->m_oAdcInitControl.ADC_NbrOfConversion = 1;
ADC_Init(ADC1, &a_opAdcControl->m_oAdcInitControl);
// ADC1 Regular Channel Config
// Enables the ADC1 Power Down during Delay
ADC_PowerDownCmd(ADC1, ADC_PowerDown_Idle_Delay, ENABLE);
// Delay until the converted data has been read
ADC_DelaySelectionConfig(ADC1, ADC_DelayLength_Freeze);
// Enable ADC1
ADC_Cmd(ADC1, ENABLE);
// Wait until the ADC1 is ready
while(ADC_GetFlagStatus(ADC1, ADC_FLAG_ADONS) == RESET)
{
}
////////////////////////////////////////////////////////////////
The code for reading ch : // a_selCH = 0x0B (ch11 --> PC-1)
ADC_RegularChannelConfig(ADC1, a_selCH, 1, ADC_SampleTime_4Cycles);
ADC_ClearFlag(ADC1,ADC_FLAG_EOC);
// Start the conversion
ADC_SoftwareStartConv(ADC1);
// Wait until conversion completion
while(ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC) == RESET){}
// Get the conversion value
if (ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC) == SET)
{
g_opAdcControl->m_oAdcChSample = ADC_GetConversionValue(ADC1);
}
ADC_ClearFlag(ADC1, ADC_FLAG_EOC);
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
Please advise,
