STM32 - Battery level

[Nicolas Bousmanne]

Posted on May 11, 2017 at 09:25

Hi to everyone,

I am a newbie in STM32 programation and I m not actually sure that is the right way to ask my question...

I hope I can find some help because I have some issues just for basic stuff.

Here is a little description : I have a STM32F405 board with a battery integrated and the voltage measure is plug on the PA2 entry of the board. After some search on internet, I am using ADC to read that measure and the return value is 4 In the first place, I thought that was done but when I let the battery discharge itself, the return value still is 4..

Can you explain me what's wrong in my code or eventually show me some documentation ?

int main(void)

{ int ConvertedValue = 0; adc_initialize(); while (1) { ConvertedValue = adc_convert_bat(); printf('Value battery : %d\n', ConvertedValue); } }

int

adc_convert_bat() {

ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 1, ADC_SampleTime_144Cycles);

ADC_SoftwareStartConv(ADC1);

while

(!ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC));

return

ADC_GetConversionValue(ADC1); }

void

adc_initialize() {

ADC_InitTypeDef ADC_init_structure;

GPIO_InitTypeDef GPIO_initStructre;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);

RCC_AHB1PeriphClockCmd(RCC_AHB1ENR_GPIOAEN, ENABLE);

GPIO_initStructre.GPIO_Pin = GPIO_Pin_2;

GPIO_initStructre.GPIO_Mode = GPIO_Mode_AN;

GPIO_initStructre.GPIO_PuPd = GPIO_PuPd_NOPULL;

GPIO_Init(GPIOA, &GPIO_initStructre);

ADC_DeInit();

ADC_init_structure.ADC_DataAlign = ADC_DataAlign_Right;

ADC_init_structure.ADC_Resolution = ADC_Resolution_12b;

ADC_init_structure.ADC_ContinuousConvMode = ENABLE;

ADC_init_structure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;

ADC_init_structure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;

ADC_init_structure.ADC_NbrOfConversion = 1;

ADC_init_structure.ADC_ScanConvMode = DISABLE;

ADC_Init(ADC1, &ADC_init_structure);

ADC_Cmd(ADC1, ENABLE);

}

Thanks to you all and sorry if the message is send at a wrong place...

Nico-

[RomainR.]

Posted on May 11, 2017 at 11:48

Hello Nicolas,

It seems that your adc_initialize () function is incomplete.

You must also configure the channel (PA2 = ADC1 Channel 2) after ADC_init()

ADC_RegularChannelConfig() configure ADC Sample time.

...
ADC_Init (ADC1, & ADC_init_structure);
ADC_RegularChannelConfig (ADC1, ADC_Channel_2, 1, ADC_SampleTime_3Cycles);�?�?
ADC_Cmd (ADC1, ENABLE);
...�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?

[Nicolas Bousmanne]

Posted on May 11, 2017 at 14:11

Thank you it seems to work fine.

I was actually doing it after the ADC_Cmd which seems to be the error.

Well it's working now, thanks you !

[Nesrine M_O]

Posted on May 11, 2017 at 15:29

Hi

Bousmanne.Nicolas

,

Thank you it seems to work fine.

https://community.st.com/0D50X00009bMM5DSAW

-Nesrine-