Hi.
I want to use the adc to measure 9 different inputs. I configured the ADC_SAR_Seq to be single ended with
input range: vssa to vdda
Reference: internal Vref
voltage reference: 2.5 volts (vdda/2)
Free running and internal clock source.
The code is simple, I start the adc and start the conversion and then create a for-loop and read the results in 16 bit, then I convert those results to voltages:
int16 ch1, ch2, ch3, ch4, ch5,......,ch9;
float32 volt1, volt2, volt3, volt4, volt5,...,volt9;
int main(){
ADC_SAR_Seq_Start();
ADC_SAR_Seq_StartConvert();
for(;;){
if(ADC_SAR_Seq_IsEndConversion(ADC_SAR_Seq_WAIT_FOR_RESULT){
ch1 = ADC_SAR_Seq_GetResult16(0);
ch2 = ADC_SAR_Seq_GetResult16(1);
etc..
volt1 = ADC_SAR_Seq_CountsTo_Volts(ch1);
volt2 = ADC_SAR_Seq_CountsTo_Volts(ch2);
etc...
}
}
}
I am able to measure the pins manually to check if the adc measurements are correct, and I am able to put 5V on one of the pins.
What I would expect is for one of the adc measured pins to return a value of 5 volts and the rest to return the value 0,
but I get results where all of my measurements are approximately the same value (about 5 when I put the 5V on one pin and 0.1 when there is nothing on the pins).
I know that the correct voltages of the pins are 0 for the ones who are not connected to the 5 volt for the connected one. Therefore I am very confused by these results, does anyone know why this happens and how to fix it?
