Setting Inputscan on SAMD21 M0 question

Using Arduino Programming Questions
1

Hello,
I am trying to read 2 analog inputs off of my Adafruit M0 Express by modifying some registers during my setup. The input pins are AIN1 and AIN2(PB08 and PB09 on SAMD21 datasheet)that im trying to read from. But im having trouble, im still kinda new to directly writing to the registers properly. From what Ive read, you can enable pin scan mode to read from multiple pins. But I have become a bit confused.So far my setup code is:

uint32_t fastADCsetup() {
  //Set input control register
  ADCsync();
  ADC->INPUTCTRL.reg |= ADC_INPUTCTRL_GAIN_1X_Val 
                    | (inputs << ADC_INPUTCTRL_INPUTSCAN_Pos) | ADC_INPUTCTRL_MUXNEG_GND;
//  ADC->INPUTCTRL.bit.GAIN = ADC_INPUTCTRL_GAIN_1X_Val;      // Gain select as 1X
  ADCsync();
  ADC->INPUTCTRL.bit.INPUTSCAN =0x01;    
  ADCsync();
  ADC->INPUTCTRL.bit.INPUTOFFSET = 0x01; 
  ADCsync();
  ADC->INPUTCTRL.bit.MUXPOS = ADC_INPUTCTRL_MUXPOS_PIN1;
  ADCsync();


  ADC->REFCTRL.bit.REFSEL = ADC_REFCTRL_REFSEL_INTVCC0_Val;//  2.2297 V Supply VDDANA //ADC_REFCTRL_REFSEL_INT1V_Val;   // ref is 1 V band gap internal
  // Set sample length and averaging
  ADCsync();
  ADC->AVGCTRL.reg = 0x00 ;       //Single conversion no averaging
  ADCsync();
  ADC->SAMPCTRL.reg = 0x00;       //Minimal sample length is 1/2 CLK_ADC cycle
  // Set up clock to 8 Mhz oscillator
  syncGCLK();
  GCLK->CLKCTRL.reg = 0x431E; //enable GCLK for ADC, CLKGEN3 = 8 MHz oscillator 
  syncGCLK();
  //Control B register
  ADCsync();
  ADC->CTRLB.reg =  0x000;//was 0x000 // Prescale 4, 12 bit resolution, single conversion
  // Enable ADC in control A register
  ADCsync();
  ADC->CTRLA.bit.ENABLE = 0x01;

It reads from 1 of the inputs properly but the other input is just the REF Voltage, when I feed a signal into the 2 analog inputs im trying to read. Any help is nice :slight_smile: