#include <avr/io.h>

volatile int Voltage = 0x7F;


void dac_init()
{

    DACB.CTRLC = ( DACB.CTRLC & ~DAC_REFSEL_gm) | DAC_REFSEL_AVCC_gc;                   // Use AVCC as Voltage Reference
    DACB.CTRLB = ( DACB.CTRLB & ~DAC_CHSEL_gm ) | DAC_CHSEL_SINGLE_gc;                    // Use Single Conversion Mode
    DACB.CTRLA = DAC_CH0EN_bm | DAC_ENABLE_bm;
    
}

void DACB_out(int Voltage)
{
   DACB.CH0DATA = Voltage;
   while (!DACB.STATUS & DAC_CH0DRE_bm);
}


void dac_init();
void DACB_out(int Voltage);

int main(void)
{
    dac_init();
    
    
   while(1)
   {
      DACB_out(Voltage);
   }
}