 //
 int shakeServo(int startAngle, int numShakes)
 {
-  const int offCenter = 25;
-
-  int rightEnd = startAngle + offCenter;
-  int leftEnd = startAngle - offCenter;
+  int rightEnd = startAngle + SHAKE_OFFSET_ANGLE;
+  int leftEnd = startAngle - SHAKE_OFFSET_ANGLE;
 
   turnServo(myservo, startAngle, rightEnd, SHAKE_DELAY);
   turnServo(myservo, rightEnd, leftEnd, SHAKE_DELAY);


void loop()
{
  // oscillateGently();

  currAngle = shakeServo(currAngle, random(5));
  delay(3000);
}

void oscillateGently()
{
  delay(TURN_AROUND_DELAY);
  //  Serial.println("------------------------------------------------------------");

  digitalWrite(13, HIGH);   // turn the LED on (HIGH is the voltage level)
  currAngle = turnServo(myservo, currAngle, RIGHT_LIMIT, GENTLE_DELAY);

  delay(TURN_AROUND_DELAY);
  //  Serial.println("++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++");

  digitalWrite(13, LOW);    // turn the LED off by making the voltage LOW
  currAngle = turnServo(myservo, currAngle, LEFT_LIMIT, GENTLE_DELAY);
}

int turnServo(Servo servo, int startAngle, int endAngle, int delayTime)

const int GENTLE_DELAY = 30;

// milliseconds to wait between servo movement: when servo is shaking back & forth
const int SHAKE_DELAY = 10;

// maximum servo movement per iteration
const int ANGLE_INCREMENT = 3;

// milliseconds to wait at one end point before reversing rotation
const int TURN_AROUND_DELAY = 10;

// number of degrees to shake servo on each side of center
const int SHAKE_OFFSET_ANGLE = 25;

//
// GLOBALS
