robot project

[sinkoman]

Sup gais, I just wanted to share this little robot i've been working on for the past little while. It's really nothing too special, the circuitry is pretty primitive and shitty, and the whole repurposed-toy-tank-microcontroller-object-avoider-bot concept has been done to death, but i'm still pretty stoked.

The chassis is a toy tank that my friend gave me to hack and play with. I gutted pretty much everything except for the actual chassis with a dremel, and then cut out the back to fit a Tamiya 2-motor gearbox. The microcontroller is an Arduino Uno that's mounted to a piece of plexiglass with 3 nylon standoffs.

The motors are controlled via a home made 2 h-bridge arduino shield based around TIP31 and TIP42 power trasistors arranged in Sziklai pairs with 2N3906 and 2N3904 transistors. I chose Sziklai pairs over Darlingtons, as the transistors already have a very high forwards voltage drop to begin with. I realize that this is a poor choice of components for the task at hand, as not only are the two transistors unmatched pairs, but their forwards voltage drops are far too high to get the little 3v motors even close to their rated stall current, but it works. The bases each high/low half are tied to a PWM output, and are kept from turning on at the same time (thus smoking) from the fact that one is inverted. Again, poor design choice, but it works.

The little servo controlled turret has a Ping ultrasonic range finder (how original!), a set of light dependent resistors, and a set of infrared phototransistors. I hope to eventually write light tracking and IR tracking modes for the bot, but object avoidance is first.

Everything is powered with an old airsoft battery that's been deep cycled far too many times to still be useful for its intended purpose, running straight into the arduino, and then to an LM317 voltage regulator to power the h-bridges.

Pics:

motor driver. The layout is pretty poor. In retrospect, I should have arranged the transistors with their tabs facing inwards, but oh well.
http://i218.photobucket.com/albums/cc201/sinkoman_iii/2011-09-04_13-16-47_607.jpg

rats nest of wires.
http://i218.photobucket.com/albums/cc201/sinkoman_iii/2011-09-04_21-09-12_480.jpg

side shot
http://i218.photobucket.com/albums/cc201/sinkoman_iii/2011-09-04_21-07-37_964.jpg

again
http://i218.photobucket.com/albums/cc201/sinkoman_iii/2011-09-04_13-15-39_677.jpg

gearbox
http://i218.photobucket.com/albums/cc201/sinkoman_iii/2011-09-04_13-17-07_147.jpg

I've yet to really start programming it, but everything works (as far as I can tell). I'll maybe take some video once I get it to start moving.

 

[DEATHMASTER]

You should install a gun and make it look like a tank. Have it defend your land.

 

[Dandan]

Looks coo. drive that in a quiet library and just see what develops

 

[Stigmata]

Program it to love :3

It reminds me a lot of Johnny-5 for some reason. Awesome stuff sinko.

 

[dfc05]

Very cool, nice job! Lookin forward to some vids

 

[15357]

Holy shit. A real life engineer.

Where did you get the parts? And how do you plan to program it? D:

I am jealous of your awesomeness.

 

[Doomination]

for honors engineering at OSU we are put into teams, and have to build autonomous robots that compete in simple games.

It's pretty neat really.

 

[Rico]

Arduino boards are really cool, I used one for a connect 4 robot for my senior project.

 

[sinkoman]

Holy shit. A real life engineer.

LOL, I wish. More like some dickhead with an Arduino board and a soldering iron, and a possibly severe case of OCD.

Although i'd love to go (back) to college some day for electronics or electrical engineering. Hell, it'd be nice to go back to college period.

Where did you get the parts? And how do you plan to program it? D:

I am jealous of your awesomeness.

Most of the parts came from Jameco.com, although I might start buying my shit from Mouser, as Jameco charges ridiculous shipping fees to ship to Hawaii. The power transistors came from Radioshack and a local shop called IC Supply, cause I couldn't be arsed to place an order for more appropriate devices. I think in any case, the only other sort of transistors that would have worked out better would have been some relatively expensive MOSFETS, and I would have had to change the entire circuit to use those, which I also couldn't be arsed to do.

The board has an onboard USB to Serial convertor, so you just plug it into a free usb port and upload code via the Arduino ide. You write programs in an extremely extremely EXTREMELY high level C++ esque language called Processsing. I'd like to someday try using an AVR dev toolchain to try my hand at microcontroller programming in actual C++, but that's for whenever I have the patience for that sort of thing.

 

[15357]

Well, you know your shit and actually know how to do this - and that gets bonus respect points in my book. I wouldn't have the faintest idea how to start it off, because the last time I learned anything about circuit boards and the soldering of was back in 5th grade.

So be sure to post pics when you get time to finish it.

 

[Vegeta897]

The board has an onboard USB to Serial convertor, so you just plug it into a free usb port and upload code via the Arduino ide. You write programs in an extremely extremely EXTREMELY high level C++ esque language called Processsing. I'd like to someday try using an AVR dev toolchain to try my hand at microcontroller programming in actual C++, but that's for whenever I have the patience for that sort of thing.

Man that sounds really cool. Like a real life version of Wiremod.

 

[Godron]

My friend told me about Arduino boards a while back. I really have to get one.




Right after I figure out how electricity works.

 

[sinkoman]

Video !

http://s218.photobucket.com/albums/...tion=view&current=2011-09-11_14-13-30_654.mp4

As you can see, the path finding algorithm, AND the hardware, still have a lot of room for improvement. I think next up is implementing a reverse function, so the thing doesn't keep on getting stuck in corners.

EDIT: another

http://s218.photobucket.com/albums/...tion=view&current=2011-09-11_14-09-48_835.mp4

 

[Acepilotf14]

It's like a cat.

 

[Robbo]

AHH HA you found it's weakness... the y axis. We'll be safe when the robots try to take over!!!

That's cool though what are you doing next?

 

[15357]

That is awesome.

I mean, it can actually use its sensor to "see". Thus did Sinkoman become the architect of humanity's demise.

 

[Vegeta897]

Nice work!

It's funny, because I made something almost exactly like this in Wiremod.

Raz can vouch for this!

 

[sinkoman]

AHH HA you found it's weakness... the y axis. We'll be safe when the robots try to take over!!!

That's cool though what are you doing next?

For the robot? Adding a set of IR LEDs to the turret so I can use the IR transistors to detect when it comes close to a wall at a really shallow angle. Low angles and walls seem to pose a problem for the rangefinder, as the soundwaves are deflected away from the rangefinder, giving the tank a hard time seeing them. A collision sensor and a reverse function are probably in order too. I might even go so far as to build a PCB for it, just as a learning experience.

As far as projects go though, I think I might start messing with multiplexed LED arrays. I've got an old digital alarm clock that would make for a pretty stylish enclosure for a 10x 30 LED array.

I'm also playing around with the idea of building a much larger, more fully featured, radio controlled robot, using a wireless gamecube controller that can probably be wired right up to a serial interface and then an RF module of some sort for wireless control.

 

[Ennui]

I have nothing to contribute to this thread, but I felt the need to post anyway just to tell you that this is pretty awesome sinkoman and I fully support this kind of content on HL2.net.

 

[Stylo]

You bitch, do you know what you've done? We'll be fighting SkyNet before we know it!

No but seriously, I like gadget-type stuff so this looks pretty cool.

Also, Honda will bring about the end of mankind so you won't take the blame. Worry not.

 

[dfc05]

Vids were awesome. All the technical stuff went way over my head, but that robot is adorable. You should seriously go into electrical engineering. My dad used to take apart and put together electronic crap as a kid, and that's what he became. (It's still a lot of studying though.)