Posted on November 23, 2015 at 14:57I am new to STm32 architecture. Trying to get the internal temperature sensor going. I am using a STm32L151VC microcontroller, STM32-QFP100 programmer adapter and IAR tool chain. I am trying to use the following code, but looks like ADC conversion is giving me some random value. Sometimes, it shows a random number between 600~700 ( which doesn't make sense as the hot calibration voltage is 626 at 100 degrees according to the data sheet), and the most other time variable AD_value shows 0. Any help/comment will be highly appreciated.
int main(void)
{
/* Configure PB.12 (ADC1 Channel18) or PF.10 (ADC1 Channel31) in analog mode -*/
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
/* Enable the GPIOB Clock */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* Enable the HSI */
RCC_HSICmd(ENABLE);
/* Wait until HSI oscillator is ready */
while(RCC_GetFlagStatus(RCC_FLAG_HSIRDY) == RESET);
/* ADC1 Configuration -----------------------------------------------------*/
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = ENABLE;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 1; // Set conversion data alignement
ADC_Init(ADC1, &ADC_InitStructure);
ADC_TempSensorVrefintCmd(ENABLE);
/* Wait until ADC + Temp sensor start */
T_StartupTimeDelay = 1024;
while (T_StartupTimeDelay--);
/* Setup ADC common init struct */
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div4;
ADC_CommonInit(&ADC_CommonInitStructure);
ADC_RegularChannelConfig(ADC1, ADC_Channel_16, 1, ADC_SampleTime_384Cycles);
/* Start ADC1 Software Conversion */
while (1)
{
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
ADC_Cmd(ADC1, ENABLE);
/* Wait until the ADC1 is ready */
while(ADC_GetFlagStatus(ADC1, ADC_FLAG_ADONS) == RESET);
ADC_SoftwareStartConv(ADC1);
AD_value=ADC_GetConversionValue(ADC1);
}
}
