ADC regular channel not ready after enabling ADC

[bluscape]

Posted on June 09, 2012 at 21:53

I'm trying to use a single ADC channel on a STM32L151 using Keil Realview and ST libraries.

After enabling the ADC I wait until the ADONS bit is set indicating the ADC is ready to convert but it does not set. Looking at the ADC_SR I realized that the RCNR (Regular channel not ready) bit is set. I'm not sure how to resolve this. Below is my ADC initialization code.     ADC_InitTypeDef ADC_InitStructure;     NVIC_InitTypeDef NVIC_InitStructure;     GPIO_InitTypeDef GPIO_InitStructure;          /* ADC1 DeInit */       ADC_DeInit(ADC1);          GPIO_InitStructure.GPIO_Pin = SMPS_FEEDBACK_PIN;       GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;       GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;         GPIO_Init(GPIOA, &GPIO_InitStructure);          // Enable ADC1 clock     RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);     /* ADC1 configuration */     ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;     ADC_InitStructure.ADC_ScanConvMode = DISABLE;     ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;     ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConvEdge_None;     ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;     ADC_InitStructure.ADC_NbrOfConversion = 1;     ADC_Init(ADC1, &ADC_InitStructure);          //ADC_DiscModeCmd(ADC1, ENABLE);     //ADC_DiscModeChannelCountConfig(ADC1, 1);     //ADC_EOCOnEachRegularChannelCmd(ADC1, ENABLE);     /* ADC1 regular channel1 configuration */     ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 1, ADC_SampleTime_48Cycles);          NVIC_InitStructure.NVIC_IRQChannel = ADC1_IRQn;       NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;       NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;       NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;       NVIC_Init(&NVIC_InitStructure);          // Enable the adc interrupt     ADC_ITConfig (ADC1, ADC_IT_EOC, ENABLE);       /* Enable ADC1 */     ADC_Cmd(ADC1, ENABLE);     /* Wait until the ADC1 is ready */     while(ADC_GetFlagStatus(ADC1, ADC_FLAG_ADONS) == RESET)     {     }     /* Start ADC1 Software Conversion */     ADC_SoftwareStartConv(ADC1);

[raptorhal2]

Posted on June 10, 2012 at 01:44

Some ST Library examples omit a 7th ADC_Init structure member that can cause grief if not initialized:

    ADC_InitStructure.ADC_ExternalTrigConv = 0; Also, try enabling Scan Conversion Mode  ADC_InitStructure.ADC_ScanConvMode = ENABLE; Cheers, Hal

[bluscape]

Posted on June 10, 2012 at 16:48

Thanks for the advice but it did not resolve the issue. Any other ideas guys?

[raptorhal2]

Posted on June 11, 2012 at 16:03

I don't have an L1 to try your code on, but in comparing it to the ADC1_IDDmeas Library example, the example enables continuous conversion mode also, and doesn't set the GPIO pin to no pull. Setting the pin to AN should suffice.

Cheers, Hal

[karlp]

Posted on January 22, 2013 at 13:18

I was having exactly this problem.  The cause was HSI not being turned on.  I was running straight after boot, and was still running from the MSI.  Because the L1 uses HSI always for ADC, instead of some division of hCLK, this was stalling when I hadn't turned on the HSI.

[haythem]

Posted on March 20, 2014 at 17:22

..\main.c(125): error:  #20: identifier ''ADC1_IRQn'' is undefined

[Tesla DeLorean]

Posted on March 20, 2014 at 17:30

Likely missing a #include some where. Review the TEMPLATE projects supplied in the Firmware Libraries for the tool chain you are using.