Tips n' Tricks for the New Hobbyist

[jsbarone]

Hey,

I've been interested in robots for as long as I can remember, but never quite had the right environment, skills or drive to take my interest to anything other than just that.  Now I've found myself in a place where I can spend some time learning and advancing my skills.  What can you guys tell me to help me out?

I'm really interested in (almost) fully autonomous robots.  I also like those little "insect type" robots that are really simple and just follow light or interact with eachother.  The kind of answer I'm hoping to get out of this is:

This is a great guide that will show you step by step how to build a robot and what components you need.
This is a location of all the software you'll need and how to use it/program.
This is where you can look to see if there is an enthusiast club near you that might be able to help in person.
This is my E-Mail address so that we can chat back and forth about your progress.

I'm not tech-stupid if that matters.  I've been working in the IT/Computer Industry for 6 years now, and have been using them for about 15 years.  I've got access to a bunch of computer junk as well, if I can scavenge any spare parts.

Well, I hope I got my questions across well.  Thanks!

[polar bear6]

if you like em little insect like bots and like to resycle stuff you probably want to buy a book called "Bugbots, junkbots and bots on weels".
its all about resycling stuff to make em little sneaky buggers .
what old computer stuff do you have at your disposal?
mostly all computer stuff have usefull schnizzels, madher boards have capacitators, nice 3V lithium battery holders.
CD players have motors and gears, DVD Burners have LAZERS(!) wich can cut plastic.
mice have IR sensors wich you can use as photoresistors.

[jsbarone]

You name it I probably have access to it.  I work for a hospital which has a crap-ton of old stuff like CRT Monitors, LCD Monitors, old computers, mice, keyboards, fax machines, etc.  Just a big room full of junk that we're waiting to recycle.  Any help as far as the other stuff?  Where to learn about it online?

[Admin]

not to discourage other people from answering . . .

This is a great guide that will show you step by step how to build a robot and what components you need.

None exist at the moment, other than kits you can buy online. If you want a step-by-step, a kit is the best route. However, I am working on a free step-by-step robot tutorial for under $50, and should be done in a month I think . . .

At the moment, the best documented robot I have is here:
http://www.societyofrobots.com/robot_sumo.shtml
It has designs, code, everything . . . but its not beginner friendly . . . and hence the new tutorial I am working on . . .

This is a location of all the software you'll need and how to use it/program.

Too broad of a question . . . software very much depends on your chosen hardware . . . 

This is where you can look to see if there is an enthusiast club near you that might be able to help in person.

The best way is to go to google and type '[your area] robot club'
Doing so for a random location, I found this:
http://www.robotics.com/clubs.html

[jsbarone]

not to discourage other people from answering . . .

This is a great guide that will show you step by step how to build a robot and what components you need.

None exist at the moment, other than kits you can buy online. If you want a step-by-step, a kit is the best route. However, I am working on a free step-by-step robot tutorial for under $50, and should be done in a month I think . . .

At the moment, the best documented robot I have is here:
http://www.societyofrobots.com/robot_sumo.shtml
It has designs, code, everything . . . but its not beginner friendly . . . and hence the new tutorial I am working on . . .

This is a location of all the software you'll need and how to use it/program.

Too broad of a question . . . software very much depends on your chosen hardware . . . 

This is where you can look to see if there is an enthusiast club near you that might be able to help in person.

The best way is to go to google and type '[your area] robot club'
Doing so for a random location, I found this:
http://www.robotics.com/clubs.html

Thanks!  I'm looking forward to that Beginner Robot tutorial for under $50.  That'll be a great resource for future robo-nerds.  Are there any inexpensive kits that you would recommend off the top of your head?  I know there are goofy lego kits and stuff, but that doesn't seem like something really worth the cash.

[Admin]

Are there any inexpensive kits that you would recommend off the top of your head?

Hmmmm nope, Ive never actually used a kit before . . . i had a roommate back in college that had a BoeBot, looked good to me . . .

I recommend getting a kit that can do these:
A) teach you a lot of the basics of making a robot (has a little of everything, not too simplified)
B) can be scrapped for parts in the future, for when you are ready to build a bot on your own (will save you lots of $$ in the long term)
C) can be modified, stuff added, etc (kits can get boring after you finish building it and write a few programs)

kits that allow various sensors, and is programmable, are highly encouraged. i havnt done extensive research into this (yet), but expect to spend about $100 for a decent kit.

find a few kits that look interesting to you, and ill give you my thoughts on them if you want 

anyone have recommendations on kits they bought/built?

[JesseWelling]

Great Boards...If I didn't need the whole linux thing for my robot this is what I'd roll with.
http://www.bdmicro.com/mavric/

Heres another great product that looks fairly extendable:
http://www.makezine.com/controller/

And, well they can work as stand alones so if you need alot of AVR's that have all the pins
broken out in an intelligent manner:
http://gumstix.com/store/catalog/product_info.php?products_id=139

For clarification I haven't used the first two but I endorse the second one...for whatever that's worth

[Admin]

as for the controllers . . . i dont recommend the first two simply cause the pins are done so badly (they lack something as simple as a power bus). the third one has a nice pinout though (as Jesse said, 'in an intelligent manner') . . .

hmmmm but what we meant by kit is everything - board, plus chassis and motors etc.

for example (they look ok, but im not necessarily supporting them):
http://www.parallax.com/detail.asp?product_id=28132
http://www.robotstore.com/store/product.asp?pid=414&catid=1552
http://www.robotstore.com/store/product.asp?pid=417&catid=1554

dont get these kinds of kits because you wont learn anything from them:
http://www.robotstore.com/store/Default.asp?catid=1548

[jsbarone]

http://www.robotstore.com/store/product.asp?pid=778&catid=1628

This one is pretty nice looking, although it's kind of expensive.  Can I piece one together for cheaper?

[Admin]

This one is pretty nice looking, although it's kind of expensive.  Can I piece one together for cheaper?

Technically, yes, you can. But if you could, you wouldnt need a kit 
Or you could just wait for me to finish my tutorial . . . but it might take me 6+ weeks since its going to be a long one . . .

Ok joking aside, look around at other places that are selling that robot or similar. Often I see kits between stores with up to a 50% difference in price. I think the BoeBot has multiple versions, some are cheaper. Robot technology prices drop crazy fast, newer kits generally give you more bang for the buck.

But yea, although Ive never used it, my general impression is that the BoeBot is a good beginner kit.

[jsbarone]

Well, I don't think I can really afford that one at this point.  I read a few reviews on it and they were mostly positive, but I'd rather start with something in the $50 range to play around with.  Can you guys think of anything programmable in that range?

[Admin]

to my knowledge, none exist . . . the lowest you can get will definitely be over $80 . . . if someone finds one, please post it!

the reason why mine is much cheaper is that im not making a profit from your pocket, nor do i have manufacturing costs

so i wrote my first draft of my step-by-step tutorial today . . . it will be a four parter . . . ill release them about one every two weeks and post them on my main page. the design is about done, and yes, its confirmed to be under $50 . . .

[jsbarone]

Well, that's pretty cool that you're doing that.  I'm looking forward to reading it and building one.  Did I mention that I have a Roomba?  I'm sure I could probably do something with that.

I found one on Amazon.com for $98.00.  It's the serial version as opposed to the USB version, which kind of sucks, but saving $50 is nice.  I think I just might wait til your tutorial.

[jsbarone]

It looks like I'll be needing to learn C to program the robot...that true?  That oughta be interesting.  Any resources for that?

[Admin]

hmmmm good question, didnt really think about that . . . .

my plan is to write up user friendly sample programs that work, and in the sample programs i explain what everything does so you can reverse engineer it. i already have a few C tutorials on my page for the very basics:
http://www.societyofrobots.com/programming_robot.shtml

i guess im doing it with the assumption that you will have some basic programming experience . . .

ill look into it and see what i can do, but if you really want to learn C and you have never programmed before, buying a book might be a good route

[jsbarone]

I've actually got a little programming experience---just not in C.  Are there any sample programs out there so I can see what the commands and language look like?  I just want to make sure I'm all ready for this thing when you finish your tutorial!

[Admin]

if you have some programming experience that will get you far - even if its just BASIC

i have source code for two of my older robots on these pages:
http://www.societyofrobots.com/robot_omni_wheel.shtml
http://www.societyofrobots.com/robot_sumo.shtml

its in C, but for PIC's. im going to use an AVR for this new tutorial. but the code will be very similar. all you need to concern yourself with is the file main.c - its highly commented and simplified for easy understanding.

i will write the code so all the hardware interaction stuff will be hidden - you only need to do upper level commands like:
led(on) or led(off)
motor_left(100)
analog_sensor1=A1

basically, you will have working sample code to tweak (not write from scratch), and you will not need to do/understand the lower level complicated port commands stuff

[dunk]

C tutorials:
http://www.cprogramming.com/tutorial.html#ctutorial

(good luck!)

dunk.

[jsbarone]

Thanks for the link---that's the one I found when I googled "C tutorials".  Admin had said:

its in C, but for PIC's. im going to use an AVR for this new tutorial. but the code will be very similar. all you need to concern yourself with is the file main.c - its highly commented and simplified for easy understanding.

What does that mean?  Should I even bother learning it?  Also, what compiler do you guys use?

[JesseWelling]

I advocate C. The reason for this is nothing hooks together your highlevel idea and low level functionality like C.
IMHO programing in C is as close to assembly you can get in a modern programing language.

I use AVR's for microprocessors and use avr-gcc to compile my C code.

As for your question: PIC micro controllers and AVR micro controllers have different architectrues. PIC is mostly based on a small instruction set and really compressed assembly code. AVR micro controllers have bigger instruction set making it easier to write a C compiler.

This really doesn't matter that much because he's going to show you high level examples while hiding the architecture.

So you will see :
light(on);
light(off);

Instead of :
PORTC |= 0x01
PORTC &= ~0x01

which most of the lower level stuff you usually abstract out any ways (unless you are squeezing for space or time complexity).

[jsbarone]

Sounds simple enough.  I'm really looking forward to getting started on this.  I've always found myself interested in Robotics, so it's going to be pretty cool to get involved.  I definitely think the future will rely heavily on robots, so it'll be nice to be even a small part of it.  Who knows?  Maybe one day we'll be involved in something that revolutionizes the industry.

[jsbarone]

You know, I've been looking around on the internet for the last few days and I've been finding a wealth of information about different types of robots (such as BEAM, Sumobots, Battlebots, Lego Mindstorm's, etc) but I haven't found anything that'll help me with it now, and frankly I'm getting a little discouraged from starting this hobby at all.

Admin, I know you're working on a tutorial, but me being the impatient nerd that I am, I really need to start on something now.  What can I do?  And if I do start on something, where do I go for support?  There doesn't seem to be too big of a robot enthusiast community to go to for support, so it kind of seems like I'd be on my own, or at best resort to posting here.

I'm just the kind of guy who needs a starting point, a wealth of somewhat easy to understand information and a support base to go to so that I can ask questions.  What do I do?

[trigger]

I'm just the kind of guy who needs a starting point, a wealth of somewhat easy to understand information and a support base to go to so that I can ask questions.  What do I do?

quick note from your post above - don't hack crt monitors/tvs!  They have nasty shocks and chemicals in store for you.

Now to your question - here's one way to get started cheap & easy. I'm a beginner too (sort of), so someone else might have better suggestions:

1) Buy a base. You can make one out of HDPE 6" x 6" x 1/4" (from McMasters--search for HDPE & follow the menus) - $4. Plan your drill holes carefully!
2) Get a servo & wheel combo ($15 each) http://www.budgetrobotics.com/shop/?shop=1&cart=378640&cat=66& (or shop around for a better deal with wheel & servo separate, then glue together with epoxy)
3) Go to the hardware store and look in the screw bins until you find something the right size to attach your servos to your base ($1-2)
4) Buy the Arduino MCU development board--an easy way to get into MCUs. It's cheap and it uses a programming language that is as easy as BASIC ($32) http://www.sparkfun.com/commerce/product_info.php?products_id=666 (see http://www.arduino.cc/en/Tutorial/HomePage?from=Main.LearnArduino for software tutorial) There's lots of help for this one. (Don't forget to get screws & standoffs at the hardware store to attach it to your base.)
5) Buy a battery pack 9 or 12 volts (about $5) (see this post: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1138892708)
6) Buy velcro to attach your battery pack to the base (get it at Walmart in the sewing isle--the stuff at the hardware store is much more expensive!) ($2)
7) Buy two photoresistors and hook them up to your Arduino somehow ($.40?)
Look for example code on how to take inputs from the photoresistors and change your servo outputs accordingly.

There you have it. A little robot for about $50-60. Admin's will be better, I'm sure. But this is one idea. Just don't give up!

P.S. You should also buy a multimeter for circuit troubleshooting. It really is a must. The $15 Wally world version works fine to start.

[dunk]

hey jsbarone,
so rather than going through online articles you might consider getting a book.
you are far more likely to get step by step instructions there.
internet articles tend to be of more use adding adding to your experience once you get started.

i've heard good things about this guys books:
http://www.robotroom.com/

i'm sure other people on here have some recommendations on this too.

dunk.

[Admin]

i think everyone on this forum who has built a bot didnt have much outside help. most of what we know, we taught ourselves (often the hard way). in the end, its your bot, you will have to do the thinking and building and figuring it out without a hand to guide you through it . . .

i think most people who have built a bot will also say their first bot was more of a failure than a success - its hard and for good reason. but the first bot is the huge learning experience, you just got to approach it with what you know. you cant expect to know how to do it without ever doing it . . . i had a math teacher who would always say 'math is not a spectator sport, you need to do it to understand it' . . . robotics is like that . . .

after all, if someone else designed it, located all the parts, wrote all the code, fully tested it, and then gave you step by step instructions to follow, can you really call it your robot?
how much can you learn from that if someone else does it for you?

but of course, making robots has a steep learning curve, and thats why im making a beginner kit for cheap. by giving people something to start with, the mountain becomes a hill . . . but if you really need hands on help, have you looked around for a robotics club in your area? (or at least state?). my experience at the CMU robotics club was priceless

i would say take trigger's advice, just go out and buy stuff, and figure it out as you go . . . that was my strategy for like my first 20+ robots

as for dunks advice, i'd recommend that too. just read and read and read about everything you can on robotics. things will start to make sense the more you understand. you're actually lucky, when me and dunk were beginners, a lot of this literature didnt yet exist.

and if you still feel its overwhelming, maybe perhaps break the project up into sub-projects. for example, just build a device that flashes a LED with software (using a store bought microcontroller). work on each subsystem, one at a time, and build your knowledge up for when your ready.

ok enough lecturing, hope that helped!

[jsbarone]

thanks for the replies, guys!  I really appreciate that list of parts.  I might just go that route, because I just have an itch to get started.  I've been writing back and forth with the guys at Parallax to see about getting a Boebot, but I think that putting something together from different parts will be a better learning experience for me.  Is that arudino board a decent quality component?  I'd rather spend a little more cash on one if it meant I could use it more in the future.  Also, is that USB I see?  and what is that next to it in the picture?  Does it require some kind of external power?

As far as a robot club in my area, I live in Santa Rosa, CA.  I know there are quite a few in San Francisco, but that's more than an hour from me so I wouldn't be able to go much.

Let me know whatcha think about the board.

[trigger]

thanks for the replies, guys!  I really appreciate that list of parts.  I might just go that route, because I just have an itch to get started.  I've been writing back and forth with the guys at Parallax to see about getting a Boebot, but I think that putting something together from different parts will be a better learning experience for me.  Is that arudino board a decent quality component?  I'd rather spend a little more cash on one if it meant I could use it more in the future.  Also, is that USB I see?  and what is that next to it in the picture?  Does it require some kind of external power?

As far as a robot club in my area, I live in Santa Rosa, CA.  I know there are quite a few in San Francisco, but that's more than an hour from me so I wouldn't be able to go much.

Let me know whatcha think about the board.

Yes, it's USB. And you need a 9-12V power supply (aka, battery). As for quality, I haven't used it (yet ). But it has quite a following, and it uses a well-established Atmel chip for its brains. You might check out their forums and see what you think.

"Better learning experience" is such a hard question to answer--what are you really asking? What makes one learning experience better than another? Are you really asking, "is this just too easy, and so I won't learn anything"? Because if that's the case, I think you'll learn a lot about electronics and robot building even if you pick up a BASIC stamp (don't do that--too expensive ). In other words, you're going to learn a lot no matter which route you pick at this point.

[jsbarone]

Sounds great.  I plan on purchasing most of this stuff this weekend.  I'll keep you guys updated.

[jsbarone]

HDPE?  I googled for "Mcmasters HDPE" and the only thing I found was an automotive parts supplier.  Is this HDPE stuff anything like acrylic/plexiglass?  I have a TAP Plastics in my neighborhood if thats the case that I'd rather use.

Edit:  Oh, and photoresistors.  Where do I find those?  Would Radioshack stock them?

[Admin]

Go to www.mcmaster.com and type in 'HDPE', then make your selections.

Or type in 'plastic' for a wider selection.

For more info:
http://www.societyofrobots.com/materials_hdpe.shtml