How to Control your Robot Using Arduino and Hand Gestures

By Mayoogh Girish

hand gestures

 

Tired of controlling your robot with a joystick? Ever thought of controlling it with your hand gestures. I wish I could control everything with my hand gestures. Sitting on a chair and controlling things like a BOSS. I loved the thought of it. So I finally came out with a hand gesture controlled robot that can follow the commands shown by hand. Sounds crazy but I promise it’s very simple.

Making a gesture control robot is actually very simple. This robot is an improvement of another DIY project, an RC car using RF module.

The robot is divided into two sessions, Transmitter and Receiver. The Receiver circuit is same as the one in the RC car project and there is a slight change in the transmitter circuit. Here we need to program the transmitter circuit to send hand gestures as commands. I will be using an Arduino as the programming platform to recognize the hand gestures with an accelerometer sensor. So let’s start making.

Required Materials

  1. ADXL335 Accelerometer
  2. Arduino OR Compatible Board
  3. RF transmitter receiver module
  4. HT12E Encoder IC
  5. HT12D Decoder IC
  6. L293D Motor Driver IC
  7. General purpose PCB
  8. 12v/9v Geared Motor
  9. 12/9v Power supply
  10. 7805 Voltage regulator
  11. Robot Chassis (Optional ) or try a DIY chassis

How Does it Work?

What is an Accelerometer?

In brief, an accelerometer is a three-axis acceleration measuring device. The one used here is ADXL335 and it has 3 axes (X Y Z).

The accelerometer is now there in almost all smartphones (No, we are not going to take it from a smartphone). You might have played motion games on your mobile (Eg Temple run). The character in the game moves left and right when you tilt your phone left and right respectively. It is done by the accelerometer.

 

hand gestures

 

How Does it Recognize the Hand Gestures?

The brain of the robot is an Arduino Uno(Atmega32). It is fed with a set of code. The gestures/motion made by hand is recognized by the acceleration measuring device called accelerometer (ADXL335). The one we discussed earlier.

 

hand gestures

 

The Accelerometer shown above reads the X Y Z coordinates when we make hand gestures. It then sends the X Y Z coordinates to the Arduino. We don’t need the Z axis. We need only X and Y. The Arduino checks the values of coordinates and sends a 4bit data to the Encoder IC in accordance with the data received from the accelerometer. The Encoder passes the data to RF Transmitter. And the transmitted data is received by the RF Receiver. The receiver sends the 4bit data to Decoder IC which decodes it and passes to Motor Driver IC. Later the motor driver makes decision to turn the two motor in required direction

Making the Power Supply

First, we will start with the power supply circuit. We need two power supply circuits. One for the transmitter and one for the receiver. The receiver circuit needs to be powered using a 12v supply (since I’m using a 12V motor). Transmitter circuit can be powered using 9v battery.

 

hand gestures

Using this diagram, wire up the supply circuit. You can also add an LED via a 1k resistor to indicate the state of the power supply.

  • IC 7805 which regulates the 12v supply to 5v (if you can not get a 12v supply, you can use a 9v supply)
  • 0.1uf & 470uf capacitor
  • 1k resistor for status
  • lED

NOTE: Use of heat sink for 7805 is suggested because we are dropping 7v (12-5 ). So lots of heat will be produced and could burn the regulator.

Making the Transmitter (Hand Gesture Remote)

The receiver section consists of an accelerometer which detects the hand gestures. It then sends the data to the Arduino. Later, the Arduino sends data to the Encoder IC in accordance with the data received from the accelerometer, and the data  is transmitted to the receiver

 

hand gestures

 

Wire up the circuit using this diagram.

 

hand gestures

An illustration of the hand gestures controller circuit

 

Uploading the Code to Your Arduino

Upload the hand gestures code to your Arduino

Making the Receiver

 

hand gestures

 

The receiver circuit consists of 2 ICs (HT12D decoder and L293D motor driver) and an RF receiver module.

Wire the circuit as per the above receiver schematic. There are 2 LEDs on the receiver board. One lights up when power is given to the receiver and the other when power is given to the transmitter. The led near the IC HT12D should be lit and this provides you a valid transmission(VT) when power is given at the transmitter. If not, there is something wrong with your connection or your RF TX/RX module. If you want to know more in detail about the receiver section, please read this article on how to create your own DIY Remote Control Car.

 

What hand gestures will the robot recognize?

This robot is designed to recognize five sets of hand gestures. Forward, backward, left, right, and stop.

 

hand gestures

Five different hand gestures for each control command

Enjoying steering your robot!!

Shrink it and Make it Permanent (Optional)


An Arduino UNO will be large and bulky on your hand. If you are deciding to make another project using the Arduino you will have to remove it and all of the connections made on it. You will lose your old work.

I don’t like doing that. So I came out with a more permanent solution. You can check out my other tutorial to learn how to shrink your Arduino project. Download the PCB layout for  a standalone version of the picture above.

 

 

hand gestures

 

Watch this standalone video in which I have transferred the code to an Atmega8 MCU. I have only shown the outputs of MCU using LEDs.

And here is a working demo of my robot controlled with hand gestures!!

 

 

 

 

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Showing 8 comments
  • Rahul soni
    Reply

    hey i am using two 9 volt battery at the receiving side one for whole circuit and other 9 volt for 12 pin of l293d ic..but the motor are not running and vt led are glowing when i tilt the accelerometer…and transmitter side i provide the supply through arudino…please any tell me solution???

  • Bogdan
    Reply

    As I see, you supplied the accelerometer with 5V, but in it’s data sheet says you need to 1.8 to 3.6v, and 5v would damage the module. Am I missing something?

  • Ahmad Awais
    Reply

    I have done this project if anyone want help then sms me on whatsapp here is my number
    +923037747429

    • Favad Jaskani
      Reply

      kindly share the code of this project

  • Ayman Mahfuz
    Reply

    I have a question. On the transmitter circuit, what are those four things that are on the right of the diagram? I’m very new to Arduino so please can someone help me. This project is due January 26

  • iyke
    Reply

    nicd but please make a step by step youtube video for us new to arduino… seeing is actually more understandable ..thanks alot

  • IKRAM
    Reply

    can i know what do use to draw the circuit and the simulation? because im using proteus 8 and they dont have the library for ht12e

  • prince
    Reply

    nice I want to know more

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