Step 7: Motor Controller

The standard gearbox and motorset of the Omnibot is great. No need to modify it. However, there is a need to control it!

So I chose the Sparkfun Motor Driver: http://www.hvwtech.com/products_view.asp?ProductID=1266

You can also use the Pololu Motor Controller, but it is expensive: http://www.hvwtech.com/products_view.asp?ProductID=915

Wiring the Motor Controller is quite simple. The instructions included with the controller you choose will have labels for each motor's + and -, as well as the 2 channels from the microcontroller. Motor Controllers are called HBridges, and buying assembled ones will save you a huge hastle in making your own.

You may do a google search on HBridge to read more about them. Simply put, they are a collection of transistors that allow you to control the direction of a motor via logic lines.

Also, if you are using the OmniBot .Net source code, you wlil notice there is an ADC Port for monitoring the motors. The motor controller I chose does not have a Voltage Load pin, but you can get around that. When the motors are under a lot of strain and load, a tiny bit of positive current wll be detected on the GND feeding the motor controller. You will want to monitor the GND with an ADC connection directly at the motor controller to be accurate.

When the monitoring software notices a teeny tiny bit of positive voltage (caused by a short) on the GND at the motor controller, the routine stops the robot, backs up, looks Left and Right, turns in the direction of freedom.

<p>Cool..</p><p>You made nice project</p><p>I made simple Do it yourself in 10 minutes bluetooth controlled home automation</p><p><a href="http://www.instructables.com/id/Take-control-of-your-house-in-10-Minutes/" rel="nofollow">http://www.instructables.com/id/Take-control-of-your-house-in-10-Minutes/</a></p>
<p> i wan to make one with the same features and more like you could put a ''Disected&quot; amp in the chest and im probably 3d print the body of the robot so it would have a awesome look to it </p><p>thanks for inspiring my project </p>
This is cool! I have to have one of these old robots laying around my parents house somewhere. Time to give it a new life!
DJ the links to the files dont work,can you fix them
Do you know if the sparkfun ardumoto motor control board is suitable for this?<br>I would like to keep to arduino related controllers for this project if I can. <br>http://www.sparkfun.com/products/9896<br><br>Also, what did you use for power? &quot;official&quot; replacement batteries are all in the 6V 4.5amp range but I think I would prefer to just use C or D batteries because they are easy to find. I'm thinking 5 should do the trick and get me in the range of both the original spec and what the arduino wants, around 7V?<br><br>Any info would be appreciated!<br>
where did you get those blue leds
Hi - Can you give a link to sources for the QR111D edge detector you used? Neither Google nor Bing can find it. Also, can you give a specific part number for the micro servo for Ping Sensor?<br><br>Thanks!
completely awe inspiring.
ps id like it if u instaled servoes for hands<br>;)<br>
could u make me one of those<br>i dont care what he looks like
cooooooooooooool iliked it
I love it have two of the Omnibots that my folks picked up for me when i was younger. now they can be fun again
Definetly get into hacking it! If you do, ask any questions my way and I'll surely help out. I have a few more additions to my omnibot that will be happening soon (one being a front display). It is pretty exciting to have a robot pet around. <br> <br>Let me know when you start getting into modding yours. It will be neat to see what you come up with also :)
i am finally getting a start. could you use a Arduino? would the code be the same?
CreatorRoboto is right. You &quot;could&quot; create this project in arduino, but it would require years of work. I created the EZ Robot project to include all of the robotic work for you. I do the hard work, and you do the creative work :) Seems to work well! - DJ
It actually really depends. The code has to: <br><br>a. Be written in C (Arduino is programmed in C)<br><br>b. Be compatible with Arduino <br><br>I had this nightlight that I was trying to build...it was written in C++...I changed the pin outs from the At tiny13 to something in Arduino. Didn't work out great...I have a busted Arduino...I finally got it up and running again after 3 weeks. <br>
dude thats pretty cool what you did <br><br>do you know where i can find a remote for the omnibot 5402<br>ive been looking everywhere on the net
Hey great guide,<br><br>I recently bought an omnibot on impulse off ebay but didn't read the add through. Bacicly I bought an omnibot with no remote or tray. I just wondered now that you have modded your onmibot would you be interested in selling your remote and tray?
Send me your address in a private message and i'll send you the remote. You can have it for free :) .. I'm still using the tray though
So cool! I would have loved one of these. Just sent a vote your way!
Thank u! That's awesome :D There are some real wicked projects in the contest. I'm impressed with them all!
Awesome idea. are you going to make it fetch you beer and nachos when all is said and done? I wish I knew how to use microcontroles. There is a whole world of builds out there that I am still oblivious to.
It looks a bit like the bot has already fetched a beer in the opening frame of the second video. Awesome project. Wish I'd had one of these when I was a kid.
Don't let that stop you from having one now :) ... The EZ-Robot project is geared toward easy robot building. All you need is the EZ-B, Servos and a Hot Glue Gun! <br>
Thanks for developing the platform. I've been having a blast.
Whoa we're online at the same time! nice. Wait till u see the next release of the firmware and ez-builder. I have a some wicked features that'll knock ur socks off :)
thanx dude! i have it doing a lot more now. there is a custom application running that gives it more of an interactive personality. the goal was a robot pet. so it will be drivin around my house and doing its own thing. last night i left it on for about 4 hours and it was great. it got stuck a few times, so i have to work on the programming a bit more. <br> <br>the microcontroller world is easy or hard. depends on the platform you chose. i use the ez-robot project so its obvoiusly really easy: www.ez-robot.com check it out :)
Nice job :D
It reminds me of that one robot from Battlebots. I think it's name was Dr. inferno Jr.
Wher do you get the Omnibot?
I purchased the shell of the Tomy Omnibot off Ebay. The toy was from the 1980's, and I modified the internals to do my own things. You do not need to use an Omnibot specifically for your robot. You can use any Robot Toy and modify it. Look at my other instructables for ideas. Also, I have more videos and robots on www.ez-robot.com
I cant find anything that big. Can you help?
you want to modify a toy robot shell into a robot? Check ebay: <br> <br>http://shop.ebay.com/i.html?_nkw=tomy+omnibot&amp;_sacat=0&amp;LH_Auction=1&amp;_sop=15&amp;_odkw=tom+omnibot&amp;_osacat=0&amp;_trksid=p3286.c0.m270.l1313 <br> <br>

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Bio: I build robots to encourage others to do the same. I believe the future is in robotics and playing a part for the future is ... More »
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