MEGA 2560

Six wheeled All Terrain Vehicle (6WD)

​Hello,

In this post we”ll be making a Six wheel drive all terrain vehicle (ATV). These are rare and hence expensive robots (at least in India). Dagu manufactures a similar 6WD chassis but its way too expensive (Rs 20000 / $ 250). So I decided to make a cheap Six Wheel drive(6WD) – All terrain vehicle(ATV) chassis out of aluminium and steel and then control it with an android mobile phone using HC-05 Bluetooth module. If you don’t know how to use a HC-05 bluetooth module click ​here for the guidelines.

IMG_20140803_212001 - Copy

Of course one can make various sorts of autonomous robots with this chassis using different control systems. I will be using an arduino Mega 2560 as the brains of this robot. Alright, so lets go ahead talk about various steps involved in making such a vehicle.

Design:

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People think that while building a robot electronics and coding are the two main steps. But its not true, in fact design is the real mother-ship. If you got that part right it will reflect in the rest of the system. A good design could provide better efficiency, low cost, good looks etc. The elegant design of this chassis is the best bit of this project.

Now, ​the first question that strikes is that why a six wheel drive for an ATV? As the name suggests a six wheel drive (6WD) means a drive system in which all the six wheels are able to move independently. Well to be honest there is nothing special in 6WD unless you provide it with a real nice suspension system. In this project I have chosen to go with individual tyre suspension as it gives better traction and more torque on an uneven surface. This design is inspired by six legged insects, although it doesn’t has legs but it sure has similar flexibility.

The Chassis:

There are many other options available in the market if you want a six wheel drive chassis. The reason why this product stands out is that its cost effective. I spent Rs 2000 (approx. $33) on this project.

Material/Parts required are:

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  • Aluminium sheet.
  • 12 L shaped motor brackets (steel).
  • Six high torque motors.
  • Six high traction wheels (10 cm diameter).
  • PVC pipe (diameter just greater than motors).
  • Screws and nuts.
  • A hammer and a nail (for making holes in aluminium sheet).
  • Nylon ties

After having all the required material here is what you need to do next:

  1. Cut the Aluminum sheet into 32 by 12 cm.
  2. Make six pieces of PVC pipe of length just greater than that of motors.
  3. Make four perpendicular diametrically opposite holes in the PVC pipe.
  4. Fit motors into PVC pipe such that holes are on the inner side.
  5. Divide the aluminium sheet into 3 sections by marking with a sketch pen.
  6. Place two L shaped motor brackets on Al sheet and mark positions such that motor just fits in.
  7. Make holes on these positions using a hammer and a nail.
  8. Affix the brackets using screws and nuts.
  9. Screw nuts into bracket and holes on PVC to affix motors.
  10. Tie two opposite motors with nylon ties.

Adding a control System:

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Now that we have build the chassis, we have to decide how we want it to work. In general, there are two control systems.

  1. AI-Automation
  2. Remote control

Automating a robot is a challenge. It is definitely difficult to implement than remote control. In this project we are keeping both options open by installing an arduino for automation. This arduino is also connected to a Bluetooth module (See PCB) which can be used for remote control. In remote control the actual brain behind movement of robot is a human brain, now imagine if a human brain is aided by a little touch of automation (example: automation an help in object contact avoidance).

I controlled the ATV through an android device via bluetooth. There are a lot of apps available on playstore for controlling arduino via bluetooth. I used Arduino BT Joystick.

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Obviously, there is no limit to what you can do with this chassis. So if you got some interesting ideas please share them with me in comments. Thank you for reading.

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Controlling Pan and tilt mechanism with Infra red (IR) TV Remote.

Making arduino wireless is a piece of cake with an IR Sensor and a TV remote. In this post I”ll show you how to build a pan tilt mechanism with servo and then control it via an IR Remote(TV remote). My favorite part of this post is the home-made PAN AND TILT mechanism. So lets get to it.

You will need:

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  • Arduino
  • L clamp. I used the one which is actually made for clamping motors.
  • Two high torque Servos
  • Nylon cable ties to hold servos and brackets together
  • Screws and nuts
  • IR Sensor. I used TSOP 1738
  • TV Remote. I used a Sony Bravia LED TV Remote.
  • .Breadboard
  • Jumper wires

First of all, we need to assemble the L-clamps and Servos together. There is one base Servo which rotates the system horizontally and then there is a neck servo which rotates it vertically. You can assemble them in any way you like as long as they are doing their function. The only thing to remember while making a pan and tilt mechanism is that it should be sturdy. There should not be any vibrations. One trick to build such firm system is to keep center of gravity as low as possible.

 

With the assembly done, its time to do wiring! 

Below are the connections schematics:

baseservo          Arduino

      Vcc         ->     +5v 

     Gnd        ->      Gnd

     Signal     ->      Digital PIN 4

…………………………………………………..

Neckservo          Arduino

      Vcc         ->     +5v 

     Gnd        ->      Gnd

     Signal     ->      Digital PIN9

…………………………………………………..

IR Sensor          Arduino

      Vcc         ->     +5v 

     Gnd        ->      Gnd

     Signal     ->      Digital PIN 2

To know schematics of IR sensor refer to datasheet above(in “You will need”).

Wiring is all done. So lets do some coding now.

You can try and use the standard IRRemote library of arduino, but I got some serious errors while using it with Servo library. I think its because both of them uses the same timer i.e timer 2. So I used this library instead.

Next step is to debug your IR remote. That is to know what code is linked to which key of you TV remote. I have provided a sketch for doing that. Its at the end of this post. Once you debug your Remote, just put in the correct codes into the main sketch(also at the end of this post) and you will have Pan and tilt mechanism with Remote control.

You can attach a webcam and use this for security purpose etc. Below is a some video I made just to inspire you!

DOWNLOADS: THE CODEDECODER CODE.