Posted on June 11, 2018 at 12:14
hi,
I'm using cubemx to initiate the project, the mcu I'm using is stm32L053C6. To that I have 2 sensors and 2 transistors connected to adc inputs. The code below shows how I get the input value, voltage, from the first temperature sensor. Then I use the same code for each value I want to read. The problem here is that the first value I read is always wrong, it gives me 2048, and it's 12 bits resolution, so...
I wonder how I can fix this?
//Start ADC readingif(HAL_ADC_Start(&hadc) != HAL_OK){ while(1) {}}//Wait for EOC (end of conversion)while(!(hadc.Instance->ISR & ADC_ISR_EOC)){}//Read ADC value//Repeat for all channels. while(!(hadc.Instance->ISR & ADC_ISR_EOC)){}experiments[0+index].temperature += hadc.Instance->DR;printf('\n ex0 i rolling %d\n', experiments[0+index].temperature);
The code for reading the voltage values for the 2 temperature sensors and transistors is as below. I read the values 16 times and calculate an average. But as I said the first value I read is 2 Is there an calibration missing? somthing that I should add so that the first reading doesent give me high?
void readRollingADC(int index){ HAL_Delay(1); //Start ADC reading if(HAL_ADC_Start(&hadc) != HAL_OK){ while(1) {} } //Wait for EOC (end of conversion) while(!(hadc.Instance->ISR & ADC_ISR_EOC)){} //Read ADC value *> ****//Repeat for all channels. while(!(hadc.Instance->ISR & ADC_ISR_EOC)){} experiments[0+index].temperature +=> hadc.Instance->DR; printf('\n ex0 i rolling %d\n', experiments[0+index].temperature);***** while(!(hadc.Instance->ISR & ADC_ISR_EOC)){} experiments[0+index].ube += hadc.Instance->DR; while(!(hadc.Instance->ISR & ADC_ISR_EOC)){} experiments[0+index].vrb += hadc.Instance->DR; while(!(hadc.Instance->ISR & ADC_ISR_EOC)){} experiments[0+index].vrc += hadc.Instance->DR; while(!(hadc.Instance->ISR & ADC_ISR_EOC)){} experiments[1+index].temperature += hadc.Instance->DR;printf('\n ex1 i rolling %d\n', experiments[1+index].temperature); while(!(hadc.Instance->ISR & ADC_ISR_EOC)){} experiments[1+index].ube += hadc.Instance->DR; while(!(hadc.Instance->ISR & ADC_ISR_EOC)){} experiments[1+index].vrb += hadc.Instance->DR; while(!(hadc.Instance->ISR & ADC_ISR_EOC)){} experiments[1+index].vrc += hadc.Instance->DR;}
How do I fix this? Does it have something to do with the code or the initiation of the adc? What I can do is to read the first value and not save it, but I don't think that's the proper way
