Undefined reference to

[guilleruiz09]

Hello, when executing this function an error appears, which we do not know what it means and how to solve it. The variable in question, handles, is defined as: extern struct Handles_S *handles;

double get_Icell(void){

//config. to read Icell (PA0)
sConfig.Channel = ADC_CHANNEL_0; // Configure ADC channel for PA0
sConfig.Rank = 1; //set the rank to 1, to read first and uniquely Icell
sConfig.SamplingTime = ADC_SAMPLETIME_3CYCLES;
if (HAL_ADC_ConfigChannel(handles->hadc, &sConfig) != HAL_OK)
{
	Error_Handler();
}
HAL_ADC_ConfigChannel(handles->hadc, &sConfig); //update the configuration

//get the ADC measure
HAL_ADC_Start(handles->hadc); // init adc
HAL_ADC_PollForConversion(handles->hadc, 200);// wait the conversion to end
adc_Icell = HAL_ADC_GetValue(handles->hadc);
Icell = calculateIcellCurrent(adc_Icell);

return  Icell;

}

The error appears at the last '}'