The Enchanted Objects kit includes a TinkerKit Servo Module.

That servo motor is not your common 180° angle adjustable unit. It's something special.

Digital Continuous Rotation (360°) Servo

It's a SM-S430R continuous rotation type (http://www.farnell.com/datasheets/1581465.pdf)

The continuous servo doesn't work like the common one.

If you connect it to an Arduino and run the Servo examples, you'll be amazed (that is: if your workbench survives it - I tested it with a long iron beam attached to it and the thing started hacking into my function generator).

On a common servo, you can call Servo.write() with a value between 0 and 180. The servo will move to a fixed position for each value between 0 and 180 and stop.

But for a continuous servo, this value determines the speed.

Servo.write(0) the motor spins counterclockwise as fast as it can - and keeps running

Servo.write(90) the motor grinds to a halt

Servo.write(180) the motor spins clockwise as fast as it can - and keeps running

A safe way to test the servo is with this minimal sketch. It will start spinning the turn the motor clockwise at a low speed, and runs at that speed forever.

Pin 9 is the Arduino control pin.

#include <Servo.h>

Servo myservo;  // create servo object to control a servo

void setup()  {
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
  myservo.write(100);
}

void loop()  {
  // this space intentionally left blank
}

I've also made a test bed that allows you to control the motor via the serial monitor. When you enter a value between 0 and 180, the motor will run with that for 5 seconds. Then it stops.

Load to your Arduino,

#include <Servo.h>

Servo myservo;  // create servo object to control a servo

void setup() {
  Serial.begin(9600);
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
  myservo.write(90);
  Serial.println("Enter speed (0 - 180, 0 is fast left, 180 is fast right, 90 = stop)");
}

void loop() {
  // if there's any serial available, read it:
  while (Serial.available() > 0) {
    int iSpeed = Serial.parseInt();
    iSpeed = constrain(iSpeed, 0, 180);
    myservo.write(iSpeed);
    delay(5000);
    myservo.write(90);
    Serial.println("Enter speed (0 - 180, 0 is fast left, 180 is fast right, 90 = stop)");
  }
}

I'm still thinking how I can use this motor in my project. Because of its peculiar behavior, I'll have to come up with something that matches with this servo.

Click here for Part 2.