Have you ever looked for your phone when it rings? You need LazyHH! LazyHH will carry your phone to you when you swipe your hand. We present a gesture activated gadgets/beverages/candies transportation device to increase our everyday laziness.


Our motivation for this project was to build a transportation mechanism which would make us more lazy and cater to our couch potato needs. The idea was inspired by the rotary tray Lazy Susan and Digilympics, which use a rail mechanism to transport objects in linear motion.


Our system consists of:
1. Arduino Uno
2. Kinect for Windows Sensor
3. Servo motor
4. String
5. Lego pieces
6. Gears and a heavy object to provide enough traction to move the string
Arduino Uno


Continuous Motion Servo


Lego cart and string

LEGO Wheel "Gear"


The system consists of an Arduino Uno, servo motor, Kinect for Windows, custom made LEGO cart, a phone and a user to perform gestures to actuate the circuitry.
System Overview

The Kinect sensors along with the Kinect toolbox detects user gestures and transmit the corresponding command to the Arduino that activates the system.

We used the Kinect Toolbox API from MSDN to recognize gestures. The SwipetoLeft gesture is mapped to move the cart away from the user and th SwipetoRight gesture is mapped to move the cart towards the user. Once a gesture is detected, data is sent through the COM port which is then sent to the Arduino to actuate the circuitry. The Arduino Uno is programmed to trigger the backward and forward motion of the cart based on the incoming signal from the Kinect sensor. A servo connected to the Arduino is used to drive the motion of the cart.

We build our own custom mechanism to convert the rotary motion of the servo to a linear motion of the cart. A string is served as a 'chain' to transport the cart. A gear was attached to the servo so that it had enough grip to drive the string/chain backward/forward. A dismantled LEGO wheel was used as our 'gear' as it provides enough traction to hold the string without slippage. We also had to ensure that there is enough tension on the string to drive the cart at all times. A combination of a HCIL cup filled with water, sticky tapes are used as suspension objects. This large suspension object maintains the tension in the string and prevents the forward and backward loops of the string from crossing their paths. A wooden plank helped us keep the movement of the cart on the same plane.




Our biggest challenge was trying to build the rotary-to-linear motion mechanism. We are inspired by the systems that uses curtain rails, however, we are not able to find a rail that comes with the pull string mechanism. We had to design and build our own pull string system that converts the rotary motion to linear.

In our initial design, we use 2 heavy ends to suspend the string to create the tension. The servo is attached to the circuitry at one end. More often than not, it resulted in slippage of the string which immobilized and disrupted the setup of the circuity. The orientation of the servo gear mechanism also played a role in the efficiency of results achieved. When we had the servo in vertical orientation, we had poorer results as G-force also contributed to slippage of the string. Horizontal orientation fared better but was still far off from what we wanted to achieve.

During the course of the project, we realized that we needed a gear mechanism to carry the string forward or backward. To design the perfect gear, we made a few futile attempts not limited to using lego pieces, custom building a gear through MakerBot Replicator, screwing a gear to the servo's mouth etc.
Gears we tried

Printed Gear

We found that the recognition of gestures by the Kinect sensor was inconsistent in near and seated modes. The performance of the Kinect in far mode with a standing skeleton was way better.


The future work in this direction would involve building a set of gestures which would enable one to control multiple miniature robots in the vicinity. In addition to the classic robot navigation problems, designing distinct but natural gesture controls is going to be a problem. We anticipate the use of short range wireless protocols such as Zigbee or Bluetooth to control such robots.


Lazy Susan
My Little Piece of Privacy


Kinect Toolbox API
GitHub code