How to start a hobby in robotics?

February 18, 2009 1:45 PM

I'd like to start making robots and tinkering with microcontrollers. Where do I start, and what do I need?

So, I'd like to make my own robots. I'm comfortable with programming (assembly and C) so I've got that part covered, but my electronics/circuits knowledge is a little weak. I have no idea what material to start with and which tools I need, nor how to put stuff together. I've read previous AskMeFi questions, however I haven't seen anything about how to start this hobby.

As an example, for my first project I'd want to create an automated wheeled vehicle that drives around. I might want to integrate motors/wheels, a proximity sensor, an accelerometer, and/or photoresistors. But what I want to make isn't very important - I want to get things that would be useful for future (undetermined) projects. Suppose I have a budget of $100-$200, but I might be willing to go higher.

For the microcontroller, I'm thinking about going with the Pololu Orangutan LV-168 or the Arduino Duemilanove, although I'm leaning more towards the Orangutan because of the built-in LCD and pushbuttons (which I would expect to use, especially for debugging and user interaction). Am I on the right track? It seems to me like the number of I/O ports is small, but is that the case in practice?

Where I'm really lost is the additional equipment, and the background on how to make everything work circuit-wise - in this area, I don't know what I don't know. For example, do I need:
- A soldering iron?
- A breadboard?
- A voltmeter/multimeter?
- Resistors, capacitors, etc.?
- A better understanding of circuits?
- ...?

Finally, I'd like to know about your experiences, good and bad. What works and what doesn't? What are the "gotchas"? Give me your best suggestions so I can benefit from your experience. Pointers to good online guides are good, but I would especially like to learn about what works well (and doesn't) from knowledgeable mefites.

(Bonus points for anyone who can tell me where I can buy what I need locally, either in Ottawa or Montreal, or online in Canada. I'd like to avoid Ebay, etc. and cross-border ordering.)

posted by Simon Barclay to technology (14 comments total)

What are the "gotchas"?

You can be virtually certain that at some point your motors will be going full speed, full power, in exactly the wrong direction. Try to arrange things so no one gets killed when this happens.
posted by StickyCarpet at 1:49 PM on February 18, 2009

I am making my way through the same process after a few workshops in a nearby university. I decided to get the Arduino, for the large user community (you should also have a look at LadyAda for its store and tutorials). For your robotic needs, there is RobotShop in Blainville (15-20 minutes from Mtl) that ships everywhere, or you can pick up yourself to save shipping fees. For electronic stuff (soldering iron, capacitors and all), there is addison in Montreal. And finally, if you can get your hands on the radioshack "getting started in electronics" pdf document (it's everywhere on the web), it's quite handy as a starting point.
posted by ddaavviidd at 1:59 PM on February 18, 2009

What about the Lego Mindstorms Robotics? Use the lego you may already have, and pick up a few motors/sensors/controllers from the company.

Here's another article on it.
posted by lizbunny at 2:04 PM on February 18, 2009

Sparkfun has a bunch of good tutorials.
posted by Confess, Fletch at 2:12 PM on February 18, 2009 [1 favorite]

What about the Lego Mindstorms Robotics? Use the lego you may already have, and pick up a few motors/sensors/controllers from the company.

Yeah, I thought of that, but I'd prefer to go the DIY route. Thanks anyways!


Sparkfun has a bunch of good tutorials.

Wow, I don't know how I missed those, but they look like a good place to start.

Keep 'em coming!
posted by Simon Barclay at 3:03 PM on February 18, 2009

I'd recommend getting your hands on a 3pi and an Arduino. They both use the same chip, and are a great place to start.

Get yourself some tools.

-A soldering iron with a sharp point.
-A multimeter.
-Some breadboards and some wire.

Actually, just look here:
Ladyada's Equipment List

Get some sensors and figure out how to use them on the Arduino, then connect them to your 3pi and go to town.
posted by Laen at 3:46 PM on February 18, 2009 [1 favorite]

Oh, for electronics in general Practical Electronics for Inventors is GREAT. It's like "Art of Electronics", but for beginner-to-intermediate hobbyists.

If you're brand-spanking-new to Microcontrollers:

Introduction to the Arrrr-duino. This just shows you how to do basic input and output using the Arduino.
posted by Laen at 3:54 PM on February 18, 2009

I'd recommend Parallax. Tons of tutorials, options, case studies, beginner to expert level stuff, customer projects, and great tech support.
posted by buzzv at 4:24 PM on February 18, 2009

Let's see.. For a $200 budget:

$30 - Arduino
$15 - Proto-shield for the Arduino
$4 - Tiny-breadboard for proto-shield
$10 - Half-Bridge Motor Driver IC
$15 - Digikey Resistor Kit. This'll give you 5 of each type of resistor you'll want.
$10 - 200 10k Ohm and 200 220ohm resistors. These are the ones I end up using most often.
$10 - 5 protoboards for soldering to.
$17 - 25W soldering iron
$6 - Some solder
$7 - Some wire
..A solder sucker.

and some RC cars from your local Good Will or other second-hand store.
posted by Laen at 5:28 PM on February 18, 2009 [4 favorites]

Wow, Laen you rock!
posted by Simon Barclay at 6:09 PM on February 18, 2009

I'd suggest "splurging" on the Weller WLC100 over the 25W iron Laen suggested above -- you'll miss having temperature control awfully fast on the $17 iron, and your tips will last longer if you can run at lower temperatures. For lead-based solder you want to turn the knob to "3" (and I'd start with lead unless you have a good reason not to; it's much easier to learn technique with lead solder).

Also keep in mind that you're taking on a lot of new technologies all at once -- between what you've said and what other have suggested, you're looking at basic EE, soldering, sensors, motors, and drive trains. Mostly I'd suggest finding a way to cut that down to a few new areas to start, so you don't have to tunnel through a dozen rabbit holes just to do the "simple" thing you wanted to do in the first place. In particular it might be useful to build some non-mobile devices (eg, program the microcontroller to turn on an LED when a CdS sensor tells you it's dark outside; grab an ultrasonic rangefinder and make a distance gun that lights up a number of LEDs proportional to the distance to target, etc) before you take on the burden of having to get the electronics working AND make a whole mobile platform.

For moving around, Sparkfun sells a dual motor gearbox kit that is pretty easy to build and can serve as a platform for the electronics; you can make a forwards-only robot with the half-bridge chips referenced above (or you can buy twice as many chips and make full H bridges, but that's another project). You'll need something like this for any "normal" DC motor. Limor also sells a motor control shield for the Arduino that takes a ton of guesswork out of making stuff move.

If you're comfortable hacking around a bit, your other option is to take apart electronic toys and replace their "brain" with your Arduino -- this can be pretty effective and really fast, if you find a toy that has all the mechanical functionality you need. (For example, there's an IC in many remote control cars that decodes the radio signal and outputs standard TTL on pins labeled "Left_Forward", "Left_Back", etc. -- remove chip, patch in Arduino, and suddenly your whole platform and drive train have been made for you.)

Oh, and I'll second pretty much everything above: Arduinos are, for me anyway, the way to go for this stuff. Practical Electronics for Inventors is fantastic if you want to learn the theory, and I use it in all my electronics classes. Sparkfun not only has good tutorials but has done a great job of sifting their inventory so that it's all well-documented and good for hobbyists to use (as opposed to Digikey, which can be cheaper but will also swamp you with 100,000 varieties of pushbutton switch).
posted by range at 7:51 PM on February 18, 2009 [2 favorites]

I haven't started tinkering yet or anything, but the Let's Make Robots guys look pretty cool to me.

The guy who runs the site made the (famous?) yellow drum machine robot which is one of the coolest things I've seen in my life. I covet one and will force my boyfriend to make me one someday.
posted by marble at 7:55 PM on February 18, 2009

Wow, thanks everyone. I've got a lot to digest, but I think I can now get a grasp on where to start.
posted by Simon Barclay at 4:55 PM on February 19, 2009

A follow-up before this thread closes: I finally ordered the parts for the first five tutorials at Sparkfun (starting here). Shipping to Canada was a pain (and expensive), but Sparkfun was great, the tutorials were easy (if a little light on the "whys" of what you're doing) but I've got a microcontroller working.

The next steps are:
- Get some soldering stuff and put it all onto a board that I can mount to a platform - looks like I'm going to order as many electronics parts as possible from Digikey this time.
- Get some motors (and required peripherals) to it can move - not sure where the best place to go is (in Canada) for the motors.
- Get some sensors.

If anyone has anything more, feel free to add it here. Thanks for all the help.
posted by Simon Barclay at 8:55 PM on January 22