// DC bias 512 (ADC 0..1023)
const float dcBias = 512;

float
Ux,
Uy,
DEG
;

void setup ()
{
  Serial.begin ( 115200 );
}

void loop ()
{
  Ux = analogRead ( A0 ) - dcBias;
  Uy = analogRead ( A1 ) - dcBias;
  
  DEG = degrees ( atan2 ( Ux, Uy ) );
  
  Serial.print ( DEG );
  Serial.print ( ',' );
  Serial.print ( 180 );
  Serial.print ( ',' );
  Serial.println ( -180 );
  delay ( 100 );
}