 int pot = A0;
 
 int photoresistors[3] = {A1, A2, A3};
+
+// CALIBRATION
 
 // if the potentiometer is between pot_locs[2*i] and pod_locs[2*i+1], then we 
 // say we are in position i.  otherwise, we are between positions.
 int pot_locs[14] = {1024, 885, 825, 690, 640, 450, 390, 280, 190, 70, 50, 24, 12, 0};
 
+// above this = white; below = black (unlodged is undefined)
+int photoresistor_thresholds[3] = {28, 6, 15};
 
 // STATE OF THE WORLD
 

// INPUT READING

// True if white gear is in front of photo resistor.  False if black paper.
boolean getPhotoresistor(int i) 
{
  // sees white gear
  if(analogRead(photoresistors[i]) > 850)
  {
    return true;
  }

boolean correct_positions[7];

// -1 if not blinking, 0..19 when blinking (0..9 = on, 10..19 = off)
int calibration_state = -1;

// 0..9 or -1 to disable debug; only show state on 0
int debug_state = 0;
