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Simple and Cheap Robotic Projects?

Cliff posted more than 10 years ago | from the automatons-on-a-budget dept.

Robotics 43

siavash_of_stockholm asks: "I have a lot of spare time this so summer, so I've decided to be productive and make my own simple robot. It will come with some basic functions and it should move around without colliding or somehow avoid getting stuck in small areas and so on. I'd prefer to do this without using the popular Lego Mindstorm-kits and instead try to use a laptop and a controller card for the motors and a cheap webcam for vision. Has anyone in the Slashdot community made a similar project (on a tight student budget) and have some documentation of it they can share?"

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I just saw a good project (0, Informative)

Anonymous Coward | more than 10 years ago | (#9437713)

at Wil Wheaton [wilwheaton.org] 's (of Startrek fame) blog. He's working on an C3-P0 clone.

MOD ABUSE!?! (0)

Anonymous Coward | more than 10 years ago | (#9440298)

Why is the parent modded down?

Re:MOD ABUSE!?! (0)

Anonymous Coward | more than 10 years ago | (#9442380)

Maybe it was modded down because it's a troll. That site hurt.

Laptop? (2)

Nasarius (593729) | more than 10 years ago | (#9437727)

The laptop isn't a bad option, especially since you've probably already got it and the battery, but you might want to look at mini-ITX or nano-ITX, which will hopefully be available soon. They're smaller and probably consume less power.

Memory wire (4, Informative)

Glonoinha (587375) | more than 10 years ago | (#9438000)

Check out the Robot Store [robotstore.com] and pay attention to all the cool things like engines, logic modules, and memory wire.

Have fun, make me one too.

Re:Laptop? (2, Informative)

siavash_of_stockholm (762530) | more than 10 years ago | (#9440746)

I looked into that the other day and found the MINI-itx cards to be ideal for this project. First of all they're very small, second they don't consume much power. I found a nice power simulator [mini-box.com] and noticed that with the EPIA 5000 I might be able to get 20W even in Network Mode.

GameBoy! (1)

ron_ivi (607351) | more than 10 years ago | (#9449405)

A GameBoy [circuitcellar.com] makes an awesome microcontroler for home robotics projects. 4 MB of flash memory, 16 MB of SDRAM, various inputs, a nice LCD for output.

Charmed Labs [charmedlabs.com] makes a great interface card and software to interact with the gameboy. This card can (but isn't required to) interface with many of the lego sensors and motors.

Maybe you can make a duplicate of this (1)

wildzeke (191754) | more than 10 years ago | (#9437760)

Johnny Sokko and his Flying Robot
http://www.dalekempire.com/GiantRobo1.html

Please learn how to make links. (0)

Anonymous Coward | more than 10 years ago | (#9442224)

Please learn how to make links.
<a href="http://www.dalekempire.com/GiantRobo1.html"> Lame 1960s TV series</a>
(without the "; " put there by Slashdot) yields: Lame 1960s TV series [dalekempire.com]

PC Motor Control Circuits (3, Informative)

WarPresident (754535) | more than 10 years ago | (#9437843)

Does your laptop have a parallel port? Here [ic.ac.uk] , here [woodyweb.ca] , and here [pilotltd.net] are good places to look for schematics/project ideas. You can scavenge stepper motors out of dead hard drives and floppy drives. Here's a nice project [seattlerobotics.org] that demonstrates building DC drive controller w/proportional speed control. Neat! I haven't built any such animals since my C64 and TI-994/a were new and shiny.

Re:PC Motor Control Circuits (2, Insightful)

k4_pacific (736911) | more than 10 years ago | (#9438394)

Also, if you are looking for a cheap means of mobility, consider building it atop the chassis of a cheap remote controlled car. this gets you a powered rear axle with a differential, plus a steering mechanism, a suspension and rubber tires. Other models feature independently controllable caterpillar style treads which can enable tighter turning radii.

Re:PC Motor Control Circuits (1)

WarPresident (754535) | more than 10 years ago | (#9438645)

Absolutely, I've thought of this, and intended to do something similar for a project a few years ago. I wanted to create a rover that could negotiate terrain using onboard AI with only user defined waypoints determining its path. To do it cheaply, I planned on using a remote control car with a wireless camera affixed to it on a rotatable base. The PC would control the rover via a parallel port I/O board connected to the remote control. The PC was to do the vision processing work.

Good plan, but I got bogged down in perfecting the AI for the vision processing and path finding. I had more fun with that than implementing the actual rover.

Re:PC Motor Control Circuits (1)

Suppafly (179830) | more than 10 years ago | (#9445247)

That is a good way to upgrade a lego robot for offroad capabilities.

Re:PC Motor Control Circuits (2, Informative)

harrkev (623093) | more than 10 years ago | (#9440813)

I have some experience building robots. It has been a few years though...

Those sites listed in the parent are neat and some good starting points. But I have some more...

---BRAINS---
I might recommend something like an old HP 100LX, 200LX or similar, or maybe an old Pocket PC or Palm. A robot large enough to hold a real laptop will likely damage furniture and walls when it hits (and it IS a "when" and not "if). You are much better off using something about the same size/wieght as a PDA. This also means smaller (cheaper) batteries, smaller (cheaper) motors, and a smaller and lighter frame. The only downside is that you get less processing horsepower, and debugging is not quite as nice as using an IDE on a PC. If you really want to use a PC, I would suggest using a microcontroller talking to your PC over a wireless serial link.

If you have the money to blow and want nothing but the best, use a PC104 card and a wireless ethernet interface. This will rapidly burn through your cash, though.

One great idea is to have a small microcontroller (cerebellum) board handle the motors and sensors, and use an RS-232 link to transfer this information to your more powerful PDA (cerebrum), which will do the actual behaviors. If you do decide to use the parallel port, you stand a small chance of blowing the outputs in your parallel port if there are any wiring mistakes. Also, your IO is very limited on a parallel port.

---SENSORS---
First, scrap the webcam unless you are looking to do something on the order of a Master's thesis. The human brain is good at taking a 2-d image and exctracting 3-d information from it. With a webcam, all you will get is three matrices of numbers, and it will take some VERY clever programming to get anything useful from that. Perhaps the best that you could do would be to have a "follow the red ball" type mode. A camera is close to useless as far as obstacle avoidance unless you are in a VERY structured environment (not your home). Shadows can be very problematic to most algorithms.

As for sensors, check out this site [mrrobot.com] . I should disclose that this site is run by a former professor as a robotics lab that I used to hang out at. Check their sensors page for the hack of the IR receiver can. This is one of the best hacks that I have seen in that it takes a remote control receiver and turns it in an analog sensor. Very cool.

---MOTORS---
The other great hack is listed under the servos section of the above web site, and will tell you how to turn a $15 hobby servo into a geared DC motor. You do not have to buy anything from there, but the documentation is worth a look.

Avoid stepper motors. They are not very powerful, and they are power hogs. The ONLY advantage is that they do not need gears.

---CONSTRUCTION---
And if you do make a small robot, the near-perfect material is model aircraft plywood. It is light, inexpensive, easy to cut with hand tools, and easy to glue together using Zap-a-Gap glue. The wood and glue are available at your local hobby store, and use a hack saw or coping saw from your favorite hardware store.

---PROGRAMMING---
I hate to toot my own horn here, but here [ufl.edu] is a document that I wrote almost ten years ago, but is still useful as a general guideline on programming robot behaviors. Also, check out all of the handouts from this [ufl.edu] web site, which is the main site for a robotics class at the University of Florida.

It should be possible to do a robot for well under $300.

Re:PC Motor Control Circuits (2, Informative)

confused one (671304) | more than 10 years ago | (#9442726)

While a parallel port seems to be a good idea, I wouldn't do it. Hooking up a motor controller to a parallel port is a good way to blow the southbridge chip on your motherboard.

If you insist on using a parallel port for control, use optical isolation on your board (the chips are cheap and easy to obtain), and, don't try to draw drive power from the port.

Words of advice from a proffesional...

Buffer driver IC's... (1)

cr0sh (43134) | more than 10 years ago | (#9445432)

Because that is what they are for...

Re:Buffer driver IC's... (1)

confused one (671304) | more than 10 years ago | (#9446430)

buffers or driver IC's don't provide enough isolation from what a motor can produce in the form of back emf.

Blocking diodes... (1)

cr0sh (43134) | more than 10 years ago | (#9449322)

For small motors, a blocking diode is supposed to be used. I would say for all but really hefty motors. At some point, yes, more isolation would be needed - but for a simple robotic project, it won't be.

Actually, you will be worrying more about RF interference from the motors than back EMF (which is why you should put at least some caps across the motor terminals - if DC - if using steppers, they should be placed between the power supply rails).

BEAM Robotics (2)

MBCook (132727) | more than 10 years ago | (#9437889)

I'm suprised that no one has mentioned doing some simple BEAM stuff. It's not programable but it's dirt cheap and can be made with junk you probably have around the house. There is a fantastic book you can probably find near you called "JunkBots, Bugbots, and Bots on Wheels [amazon.com] . It can be funny, shows lots of simple robots, and other great stuff. Check it out, I think you'll be impressed.

Other than that, build it yourself. Take two servos (you can get 'em pretty cheap at hobby stores) or just two little motors (make an H-Bridge out of some transistors), add a microcontroller (PIC, AVR, or Basic Stamps are self contained), some simple switches or photocells and some random stuff (maybe some wood to make a simple frame or something) and you'll have a cheap robot that you can program and mess around with.

Re:BEAM Robotics (1)

toygeek (473120) | more than 10 years ago | (#9445185)

Hey! That's what I did! How dare you take my idea! :p

I got that book from the library, and built the light following bot that uses an LM386 op-amp as its 'brain'. It works well and I am happy to have done the project.

Stiquito (3, Informative)

prostoalex (308614) | more than 10 years ago | (#9437910)

Well, first the disclaimer - I know nothing about this project that I will link to, but was pretty interested in the same thing.

I've written a bunch of book reviews [moskalyuk.com] , including those on Slashdot, and some publishers are sending me now catalogs with upcoming titles as part of their reviewing program.

So, anyway, Wiley has this book with the robot kit [wiley.com] , that they plan the next edition of some time this September, although the publisher told me before that the deadline might move into the future. I have not read the previous edition, nor have I played with it.

It seems to have received brilliant reviews on Amazon [amazon.com] for that 1999 edition, so I'd suggest just perusing it and maybe buying the book+kit used if it's in buildable condition (i.e. not the robot that is already all built, polished, given guns and ammo, and right now just needs the ON switch to be turned).

Re:Stiquito (1)

gmiller123456 (240000) | more than 10 years ago | (#9444418)

I built a Stiquito, it was pretty fun. There's also and "Advanced" version of the book which involves using a microcontroller (AVR 89c2313 IIRC). It's been a while since I messed with it, but it was interesting.

One word: Scott Edwards is a great starting point (3, Informative)

bergeron76 (176351) | more than 10 years ago | (#9438219)

If I'm not mistaken I believe that Scott Edwards [seetron.com] is one of the most prominent of the latest generation of robotics pioneers. His SSC and other projects have (in my opinion) helped to shape the aftermarket/hobbyist robotics industry.

I wanted to give him due propers for his project back in 1996, but I never really had an opportunity (I was too busy studying women and beer at FSU at the time).

Use a microcontroller (4, Informative)

Laser Dan (707106) | more than 10 years ago | (#9438235)

I wouldn't use a laptop, then you have to have a robot big enough to carry it around. You are also pretty much limited to the parallel port for I/O.

Look into microcontrollers (the most common are the Microchip PIC [microchip.com] and Atmel AVR [atmel.com]

A microcontroller will give you heaps more I/O pins, and PWM for driving motors, serial ports, analog/digital converters etc Both PICs and AVRs are available with all sorts of combinations of features.

There are plenty of resources available for both, look in newsgroups and search with google. GCC for the AVR is available for linux and windows so you can easily write C/C++ code for them. Also look into AVRfreaks [avrfreaks.net]
Look at the newsgroup comp.robotics.misc for other people doing similar things.

Good luck!
-Daniel

Re:Use a microcontroller (1)

Anonymous Coward | more than 10 years ago | (#9438509)

A microcontroller is good for simple robots, but doesn't leave all that much room for expansion later. Plus, it's not so easy to do vision stuff, even if you do use a CMUcam, there isn't much processing power.

A good option is an industrial single-board computer. The PC104 standard is less than four inches square. Even the EBX format is usable, at abotu 5"x8". I picked up a single-board computer for less than $50 on eBay; it was brand new. And since they are designed for controlling things, they often have special I/O ports. Mine has 48 interruptable I/O ports in addition to a standard parallel port and four serial ports. They typically run off 5 volts and are perfect for medium to large sized robots. And I'd suggest building a larger robot; it's easier to build because you have lots of elbow room, you can use good-sized batteries, car window motors from a junkyard, small solid rubber wheels from the hardware store, etc.

Re:Use a microcontroller (2, Interesting)

JohnFluxx (413620) | more than 10 years ago | (#9439241)

I second using microcontrollers.

I just wrote a basic network stack for the microcontrollers for the lasers our company produces. All the sensors measure the temperature, with feedback loops to the heaters. Several controllers control 5 or so temperatures and heaters each. The controllers are on a serial bus, with another controller for a usb connection.

It's fun writing code knowing you only have a few bytes of memory. heh.

What about using a PDA? (2, Interesting)

baywulf (214371) | more than 10 years ago | (#9438578)

There is some book on robotics I read that uses a Palm Pilot as the brain of a robot. The catch is that you have to build a simple serial to parallel convertor so you can interface the Palm to the servos and sensors. An old plam can be gotten for $20-$30 and it has an IR sensor, display, fast cpu and lots of memory compared to a microcontroller.

Look into PC/104 stacks (1)

ReverendRyan (582497) | more than 10 years ago | (#9438818)

I'm building a submarine using a PC/104 stack. Found almost all the parts on eBay, including a relay controller and 20 channel servo/stepper motor controller, as well as the PC/104 mainboard. This [ebay.com] is exactally what I bought, but there are others.

My requirements are way different than yours, however. I'm going to require a rather large control program onboard the sub to reach the level of atonomy I'll need for deep dives.

Good luck to you.

Re:Look into PC/104 stacks (1)

crucini (98210) | more than 10 years ago | (#9439935)

That's cool - I've thought a lot about doing that. How will you build the body? It's tough to design something that will resist pressure but can be opened up completely for access. I had some ideas of using PVC pipe for the pressure hull and building a much lighter hydrodynamic envelope around it. The ballast tanks would live in the annular space between.

Possibly the whole inside can be a chassis that slides out one end - but that makes it hard to connect sensor and actuators.

Re:Look into PC/104 stacks (1)

harrkev (623093) | more than 10 years ago | (#9440853)

One way is to build the hull to handle the pressure, and pumping the thing up with high-pressure air (bicycle pump). Then, if you are going down to 60 feet, just fill the hull with 40 PSI or so, and if there are any small leaks, air will bubble out instead of watter getting in.

Re:Look into PC/104 stacks (0)

Anonymous Coward | more than 10 years ago | (#9441613)

Scuba regulators do a good job of using a tank of compressed air to automatically match the pressure of an enclosed space to the pressure on the outside.

The air pressure approach is what real submarines use, too.

Hmmmm... (0)

Anonymous Coward | more than 10 years ago | (#9441973)

A GIRL Robot? This is gonna be the best prom ever!

Easy and cheap (0)

Anonymous Coward | more than 10 years ago | (#9442193)

Old floppy drives, especially 5 1/4", are good for stepper motors and controllers. Salvage them from old computers along with the power supplies. On the controller's edge connector there are three pins you need: ground, direction and step. You can drive these signals from the parallel port of your laptop. You can epoxy the motors to lego blocks or meccano or whatever other construction set. This is easy enough that you can get it going in an afternoon.

Interested in CNC? (2, Interesting)

ivan256 (17499) | more than 10 years ago | (#9442529)

This may not be what you were thinking when you thought "robot" but it uses all the same control principles. Check out John Kleinbauer's [crankorgan.com] site. He's got plans that are great for a beginner. I purchased his "Brute" plans and the really walk you through every step, from finding the materials to programming. I've changed so many things from the plan since I started building that it's barely the same machine, but the plans helped me to avoid problems I'm sure I would have hit without a framework from an experienced designer to follow. Using PVC, Delrin and aluminum as materials makes the construction fairly easy with a minimum of tools too. For one section where I needed an extra precise cut I had a local metal shop make the cut on their abrasive chop saw for me, but other than that the construction has all been done on the tablesaw and drill press. It's been a fun project.

Productive? (2, Funny)

phamlen (304054) | more than 10 years ago | (#9443415)

I have a lot of spare time this so summer, so I've decided to be productive and make my own simple robot.

Only on Slashdot would this be called "productive"...

Toy Robots Initiative (1)

awtbfb (586638) | more than 10 years ago | (#9443631)


Check out the Toy Robots Initiative [cmu.edu] at Carnegie Mellon's Robotics Institute. In particular, the CMUcam [cmu.edu] and Palm Pilot Robot Kit [cmu.edu] are worth checking out.

Evolution Robotics (0)

Anonymous Coward | more than 10 years ago | (#9444066)

Evolutionrobotics.com has an interesting kit (ER-1). However they are discontinuing the ER-1 hardware and focusing on just software. So if you like it, you better buy one soon.

P.S. Anyone ever notice how in older movies (40's-50's) they called robots, "ro-bits"?

microcontrollers... (3, Informative)

jotux (660112) | more than 10 years ago | (#9444129)

I'm surprised no one has suggested a Basic Stamp. Personally I have stopped using them because I started needing more power on my projects, but for simple robot platforms, they are a pretty good teaching tool. If you get a BS2 kit [parallax.com] with one of the books to go a long with it, you'll basically have everything you need to get started. You wont have laptop control, but if you are interested in controlling it with a laptop I would try rentron [www.rentron] and get some transmitters/receivers and play with making it wireless. The basic stamp is limited in it's ability, but its hard to find any other kind of robot kit that comes with an entire curriculum like anything from parallax does.

Re:microcontrollers... (1)

jkrah (313143) | more than 10 years ago | (#9459301)

I have to say the PICAXE controller are also a great introduction ... I paid $AU15 for a basic chip and it only takes 2x resisters to interface to your serial port.. dkownload the programming env (free) and your away.,, they are quite simple chips but have in built PWM, IC2, (dallas) 1W interface and ps2 keyboard support all built in... they are just TOO EASY!!! get an 'X' veriosn though... you will find the extra memory very usful.....

Palm pilot robot (1)

kryptKnight (698857) | more than 10 years ago | (#9446336)

http://www-2.cs.cmu.edu/~reshko/PILOT/

Has instructions and software ready made or you could base something different off of it. Pretty cheap also.

Tutorials (1)

kah0na (788907) | more than 10 years ago | (#9447478)

Check out http://tutor.al-williams.com http://www.piclist.com and http://www.avrfreaks.net

Re:Tutorials (0)

Anonymous Coward | more than 10 years ago | (#9451031)

Linked: tutor [al-williams.com]
piclist [piclist.com]
avrfreaks [avrfreaks.net]

Good links.

Control via laptop? (2, Informative)

Satan's Librarian (581495) | more than 10 years ago | (#9447559)

So you want it wired to a laptop? If so, one thing I didn't see scanning the comments is Weeder Technologies [weedtech.com] ' controllers. They do RS-232, which is a lot more friendly for a variety of control options than many of the parallel-port motor controllers.

I used their digital I/O and stepper motor controllers for my 3D scanner [codevis.com] project - they're pretty good for low-res, low-budget projects.

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