RC truck robot conversion

This Instructable covers the conversion of a cheap off-the-shelf RC truck into a powerful robot vision platform capable of ball following, etc.

I always like seeing the projects around the world using expensive robots, running complex vision processing software and dreamt of the day I would have my own to play with.

Win the lottery or build one on the cheap?

Cheap wins every time.

I say cheap, but what I mean is cheap-ish. It depends on how complicated you want it to be and how much you have lying around. Maybe it should be "cheap compared to a Corrobot or Whitebox robot" (although they have much more functionality)

Anyway.

Parts required

Toyabi Skullcrusher RC monster truck
SSC-32 for webcam tilt
Logitech Pro 9000 webcam
Sabertooth 2x10a speed controller
Dell C610 laptop system board + proc + memory + wireless
12v - 19v converter to run laptop from 12v SLA battery
12v battery (I used a 12v SLA 7ah but its a bit too heavy, maybe a LIPO?)
RS232 - TTL converter (homemade or Ebay) for Sabertooth
USB - RS232 converter for SSC-32
Remote control unit and keyfob (homemade or Ebay) - this is a failsafe so I can cut power to the Sabertooth
USB hub
12V fan
Old satellite set-top box - emptied this and used it as a box to house it all in.

Software

Windows Xp
Roborealm
UltraVNC

Step 1 Sourcing the RC truck

Whilst surfing Ebay one day I came across new RC monster trucks selling very cheaply. The interesting thing about them was that they had tank-style steering instead of the normal Ackerman steering like most RC trucks.

They can be bought in Europe from Seben racing and in the USA from Amazon and are called "Skull Crusher" from Toyabi.

http://www.amazon.com/Remote-Control-Scale-Monster-Yellow/dp/B000ODT7RK

Here are some videos of the trucks in action

http://www.wilhelmy-it.de/seben/pictures/racing_king/king.html
http://www.youtube.com/v/GFLU0xfkD3s&hl=en

I had a good robotty feeling about these asked my better half to get me one for my birthday.

The truck is HUGE and comes with a simple speed controller which is on/off rather than proportional, still, it was amazing what could be achieved with such a cheap model.

Stock, it will spin on the spot, climb all sorts of objects and gradients.

It has independent suspension and gearing to each wheel and runs from two small-ish motors. It is VERY big and came in an enormous box.

Construction is better than expected for such a cheap model, but the tyres are some kind of foammy PVC moulding. Apart from that, lots of space on board and has springs at each corner. The transmission is by gears down 4 articulated arms to the wheels.

Comments

[tommytwoeyes]

So you were able to control it complete from the dell pc using Roborealm?

For someone with no experience using a Sabertooth speed controller, would you say that would be easier than using an Arduino UNO and motor controller?

Thanks! Awesome bot

[OracsRevenge]

Hi,

Roborealm has an inbuilt control module for interfacing with the Sabertooth so there is nothing to learn for it, you just need to tweak some of the variables in the module to get the right responses.

The entire robot is controlled from RR, even tilting the camera up and down (via the Lynxmotion servo controller)

Roborealm really needs to be run on an onboard PC, if you are using an Ardunino, you could possibly use it as a control/sensor slave for the robot back to a base PC running RR.

Thanks

[tommytwoeyes]

Thanks man.

Would any typical laptop PC board work? What are the minimum system requirements for the board in a bot like yours?

Tom

[OracsRevenge]

The better the board, the more frames per second Roborealm can process.

This leads to faster and more accurate control of the robot.

If I was making the robot again, I would use a cheap Netbook running windows. as they are much easier to power and you can see the results on the Netbook screen.

You can still slave using openVNC to another laptop so you can see what it's doing and take control at a distance if you need to.

You are probably best to download the trial version of Roborealm and play around for a while with a webcam.

[tommytwoeyes]

It sounds like really awesome software. Thanks for your advice!

[Dearden805]

Whats the total cost???

[wareneutron]

it is working without remote
it is computer controled

[Justdoofus]

NAWWWWW YA THINK?

[vicky666]

(removed by author or community request)

[hintss]

well, I found out, from reading that, that electrolytic capacitors blow under PWM. evidently not a waste of time for me. I also found out about roborealm.

[Phoenix17]

Dude don't hate. If you don't like it, then don't hang around long enough to post a comment. Or contribute and make it better. One of the reasons I like this website is because everyone's usually friendly

[zack247]

so then how come you haven't done it yet? where is your instructable on it?
exactly.

[MCzone]

he has nothing against his desighn, or he does not know how

[jssteinke]

When I do this, I'm going to program it in labview. :) NI vision assist is easy to use.

[kyle brinkerhoff]

yuck! dont waste your time with that garbage software! i used it when i was doing frc in school and it was soooooo limiting ! go check out c# 2008 and openCV it'll blow your mind! plus you dont have to own that silly compact Rio. 700 dollar paper weight!

[jssteinke]

Haha, i respect your descision, I'm in FRC too! I am just saying that vision assistant is very easy to use, i would like to (re)learn C#, i have used C dialects in the past. I've been wanting to write our code in the C IDE, that comes with the FRC KOP, but it'd be easier for newbies to learn labview, so i have to continue the legacy, lol.

[kyle brinkerhoff]

yeah its just that all the frc stuff is sooo cushy! it never gets down into the nitty gritty of device i/o, everythings all wrapped up so in a way it is fast to code for their platform but so limited. but seriously check out c# its very intuitive and super easy to learn because the ide suggests code for you.. BTW GO BUY AN ARDUINO! learning how to code on that is awsome because its sooo similar to other languages, java, c ,c++, processing, ruby, perl...

[hintss]

our cRIO isn't detecting battery voltage, even though it turns on. any help?

anyway, I think that the cRIO is a form of a PLC, isn't it?

[jssteinke]

Yeah the cRIO is a PLC, it is mainly used as a FPGA, but also has a ARM or something in it. One thing to try is to make sure your analog input board is connected to the right slot, and the module in that slot is right. i think its a 9134 or 9234 or something like that. The smaller connector. The cRIO cant read the voltage you give directly to it though, it can only read the voltage on the analog slot. Also make sure on the analog breakout board, the big 2 pin connector is connected to your power distribution board. If this dosent help, just ask for more help.

[hintss]

well, we moved the parts around, and it still wouldn't work.

anyway, where exactly is the voltage read again?
oh, also, the motor controllers are blinking red, could this be related?
and the thing without the repurposed parallel port goes on the side with ethernet, right?

[jssteinke]

The voltage isnt read from the voltage coming into the ethernet side of the cRio with the 4 pin connector thing. The voltage is read using the Analog Breakout Board wich plugs into one of the crio modules. You can look at the FRC control system manual here http://www.usfirst.org/uploadedFiles/Community/FRC/Game_and_Season__Info/2010_Assets/3-2010FRCControlSystemComponent%20DatasheetsRev1_enc.pdf

also try looking at the cRio manual http://decibel.ni.com/content/docs/DOC-2632

If you still need help just ask

[hintss]

so the analog board is the one with a red PCB connected an top, right?

[jssteinke]

Yes it is

[jssteinke]

Also, the motor controllers should always blink red when idle. The only stay solid colors when you send FOrward/Backward commands

[jssteinke]

Yeah, i have an arduino, and have created lots of awsome things on it, our FRC team was thinking of using it instead of the cRIO, for the fun of it.

[kyle brinkerhoff]

haha! ive done that too! its actually way easy to convert the hardware to work with a arduino, just take your time and make some custom connectors on a protoshield to your arduino, also i used a computer with vspe installed to remotely drive the robot through a adhawk network

[jssteinke]

Thanks for the idea, weve been trying to find a way for wireless communication, we'll probably use the ethernet shield. Something fun we were thinking of doing for some school cred, would be to put the frc bot on our schools wireless, then just drive the robot around using the IP cam for wireless vision

[kyle brinkerhoff]

dude! thats also what i did! hey if you want some software to drive the whole thing email me! i wrote it all in c# (-arduino code)

[jssteinke]

I'll pm you soon, hope to hear from you!

[[corosive]]

is it really expensive?

[wareneutron]

in jimmy neutron cartoon
it is a pet of jimmy names goddard

[wareneutron]

it is like a dog

[cdousley]

cool project
iwant too do this but i dont have much money to do it with i hava a laptop and a web cam i don't need the web cam tilt also im not taking the laptop apart im cutting off the screen and i can use a terminal block to put it on when i need to
i found the car for 5$

so is there any way to make this for 50$ or less
also if it would make it cheaper  its going to be remote controlled from thecomputer its vnc'd to so if its more expensive i dont need to follow balls and stuff but it would be fun. 
THANKS!

[TANKERTOY]

I managed to grab a few free parts from some RC sites. Just offered postage charge and received quite a few parts for RC Tanks from here. You can also email and try your luck :)

[kyle brinkerhoff]

http://www.instructables.com/id/open-cv-arduino-many-hours-AWSOME/
hey heres what i made. its super cheep! (in terms of robots) all it is made of is just a peice of plexiglass, 4 servos, wheels i made and a arduino.

[cdousley]

(removed by author or community request)

[cdousley]

(removed by author or community request)

[cdousley]

ok i consolidated my comments so where can i get the sabertooth also i have a laptop battery so all i need is the sabertooth and the motors im using my own motors,what kind would you suggest and what battery would you suggest

[cdousley]

heres the car im usingwww.ridemakerz.com/shop/productdetail.aspx

[OracsRevenge]

Hi,

Use of the Sabertooth was more to do with its compatability with the Roborealm software. You need to double check that the size of the car you have will support your laptop. Also, the main deciding factor when choosing speed controllers is the voltage and current draw of your chosen motors. (http://www.trossenrobotics.com/)

I have now changed my prototype to use a normal unmodified laptop. I achieved this by using LIPO batteries to reduce the overall weight and improve the time between charges. (Only use LIPOs if you know the risks involved and are prepared to be very careful)

Most of the commercially available low power speed controllers would need you to write a small/simple program to send the correct bytes through to the controller via USB or serial port. i.e. Sabertooth / Polulu , Phidgets, etc. A google search will find you more information on these.

I would suggest that the absolute cheapest way to do these things is to either hack an existing speed controller from a toy car, or if you are after very basic on/off controls, you could also ways google "parallel port relay board" or similar. I am sure there are a few instructables on homemade controllers via USB / serial / parllel ports.

You should be able to get extra help from a robotics forum such as Trossen or Lynxmotion.

Have fun !