HAL_ADC_Start(&hadc1);
while(HAL_ADC_PollForConversion(&hadc1,0) != HAL_OK);
measurement1=HAL_ADC_GetValue(&hadc1);
HAL_ADC_Stop(&hadc1);

HAL_ADC_Start(&hadc2); //start regular conversion of regular group (channel 4 and 5)
while(HAL_ADC_PollForConversion(&hadc2,0) != HAL_OK);
measurement2=HAL_ADC_GetValue(&hadc2);
measurement3=HAL_ADC_GetValue(&hadc2);
HAL_ADC_Stop(&hadc2);