 #define PIN_LDR_DOWN  1 // PC1
 #define PIN_LDR_LEFT  2 // PC2
 #define PIN_LDR_RIGHT 3 // PC3
-#define THRESHOLD_LDR_VIRT 20
-#define THRESHOLD_LDR_HORZ 20
+#define THRESHOLD_LDR_VIRT 25
+#define THRESHOLD_LDR_HORZ 25
 
 #define SERVO_PIN_VIRT 8 // PB0
 #define SERVO_PIN_HORZ 9 // PB1


void tkr_move()
{
    int dist_virt = tkr_dist_virt();
    int dist_horz = tkr_dist_horz();
    Serial.println(); 
    
    if (dist_virt) {
      // move up or down, within range.
      byte deg = map(dist_virt, 100, 1023, 0, 170);
      servo_virt.write(deg);
    }

    if (dist_horz) {
      // move left or right, within range.
      byte deg = map(dist_horz, 0, 1023, 0, 180);
      servo_horz.write(deg);
    }
    
}

int tkr_dist_virt()
{
    int up = analogRead(PIN_LDR_UP);
    int down = analogRead(PIN_LDR_DOWN);

    
    servo_virt.attach(SERVO_PIN_VIRT);
    servo_horz.attach(SERVO_PIN_HORZ);
    
    servo_virt.write(90);
    servo_horz.write(90);
}

void loop()
