Small Embedded Computer with 802.11 for RC Car? 25
Milo_Mindbender asks: "For
some time now I've been wanting to build an RC car with an on-board
computer and an 802.11 link back to the PC in my office for
telepresence experiments (and just plain fun). As I'm planning on
doing this on my own dime, the big problem has been finding a
reasonablly cheap and low power embedded system board with 802.11 and
the right 'ins' and 'outs' to handle controling the motors (a
parallel port at minimum)." Many seriously cool devices could come
from an embedded 802.11 system, and I'm sure computer controlled RC cars
are just the beginning. Has the Embedded Computing camp hopped on the
wireless networking bandwagon? If not, what's the delay?
"I'm interested in doing two versions of the gadget, one using a system with a less powerful CPU that could do simple preprogramed moves and a second one that would have a CPU with enough power to do low-res video and two-way audio. I figure it would be a riot to remote drive one of these things anyplace in the office complex that has 802.11, stick a high-gain antenna on it and you could probably send it down the elevators and out into the parking lot! Has anyone seen an embedded system with 802.11 of either power level that might fit the bill?"
Nice idea (Score:1)
It sounds like you'd need a custom type board for it, but I think this could definately be the new style of remote controlled stuff...
Re:Nice idea (Score:1)
Try This (Score:2, Interesting)
pc-104 board with a crusoe (Score:3, Informative)
(other pc-104 boards with much slower cpus are available for a bit less money)
Telepresence robot (Score:3, Informative)
I built one while working at OGI a few years ago. I've got a copy of the pages on my current server, at http://www.temple-baptist.com/~omega/ogimabot2/ [temple-baptist.com], with a little info on it. I should see if the prof. I was working with still has the slides to convert to HTML...
They're supposedly going to be building a new one soon, and so my research into a next-gen robot may be put to use. I was looking very closely at the Cell Computing parts (http://www.cellcomputing.com/ [cellcomputing.com]), which aren't cheap ($1k-$1.5k depending), but are the right size and somewhat designed for that kind of stuff. Put that in (instead of on top of, like the current bot) the car (thinking of using a monster-truck chassis) and you can do pretty good. Email me if you have other questions, because I spent a huge amount of time on this project and its related issues.... nospam_omega@temple-nospambaptist. com
hmmm, I may do this (Score:1)
But, how would you power the computer?
You could use a Laptop, but that would take all the fun away.
I would be more interested in... (Score:1, Funny)
Use this to control the car as well.
Re:I would be more interested in... (Score:1)
A PC is the wrong tool. (Score:2)
If you think about what a car needs to do, 802.11b becomes more complicated than the actual application.
802.11 and Telepresence... (Score:3, Insightful)
Honestly, if you wanted to do such a thing, I would look into using a 1/4 scale R/C car (read: big, noisy, and expensive), or possibly a go-cart (ie: network enabled Yerf-Dog). Either way, it won't be cheap, but you will gain the power needed to keep everything running for a while.
If you don't need to keep things running for a long time, or you don't need the range, then why do the 802.11?
Grab an FM or PCM radio control box, hook it up to the computer, and control the car. Use VHF/UHF for the camera feedback loop - if you want data feedback, you might try dropping a line of LEDs in the video frame (ie, 8 bits with a read out, digitize using a frame grabber at the remote PC), or look into dropping data into the VBI (potentially that would be more power consuming - ie, to find a VBI insertion module small enough that uses R/C car voltage levels). Or, use telemetry radio modules (Parallax sells them for the basic stamp series).
You would have all the telepresence experimentation room, but could keep the package small and relatively low cost...
Smallest and cheapest Ethernet to real world (Score:1)
"Has the EC camp hopped on the wireless idea?" (Score:1)
You could cheat... (Score:1)
That way you wouldn't need any bandwidth for the cAmera, which would run about 200$
and a UHF controller with 8 i/o pins can be had for about 100$ at hobby shop.
The basic stamp is about 60$ from parralax.
You could rig the Remote right to the motors and such, but I would hook it up to a computer, that way you have a stationary computer controlling it, and put a tv-tuner on it, so you can see the UHF camera aswell. Then, create a perl program that would say....output +5 on a certain line on the LPT port to turn left, +5 on another for right, etc.
That would be hooked the the remote, which would inturn put +5 into the Basic stamp, which would then execute the turn.
I made one... (Score:2)
Pretty fun. The range on the remote wasn't amazing though - could fix that by going to a better car.
-
high-gain antenna (Score:2)
Just to clarify, in case it helps... (not nitpicking here). High gain antennas are, like the name says, antennas that transmit stronger signals than 'usual' ones. However, they don't use any kind of magic to do this; there is a price. They are more directional, meaning that they exhibit high gain in one direction and very low gain in others.
An example of this is a flashlight (after all, light is just another form of electromagentic waves). If you take the reflector off of a mag light, you get a bulb that glows equally in all directions (omnidirectional). If you put the reflector on, you can light something much brighter, but you have to point the flashlight directly at it. Also, the area behind the flashlight is completely in the dark.
So, a high gain antenna for your car would probably do best at the transmitting end, where you can point it at the car as at moves. An ordinary whip antenna (not quite omnidirectional - it's ineffective when you view the antenna end-on) on the car should be fine.
If you want to get really fancy, then go ahead and get a high gain antenna for the car. The problem is that you'll need some sort of tracking device to aim this antenna back at the base station. And when you detect that you've lost the signal due to misaiming (hit a bump, jumped off the curb, etc.), you need an algorithm to autonomously find the base station before you get run over by a big truck. Now you know one reason why nasa missions are complicated.
Speaking of Access Points... (Score:1)
1. Access points are getting cheaper every day.
2. Companies line DLink and others make very small AP's that could be used.
3. AP's contain an small embedded computer with a CPU, some FLASH memory and an 802.11b card (often the same PCMCIA card used in notebook PC's, just contained within the AP)
It would take some work, but I believe with some hacking you could build an add-on module with some support firmware to allow for external I/O. I have a Addtron AP that I couldn't resist cracking open to look at. I noticed there was an AMD 80186 embedded CPU inside. I believe this is compatible with the 80x86 so you may be able to write code in C++ or Intel Assembly language to program the chip. Just some ideas...
CerfBoard (Score:1)
A slashdot fave, why not consider the Intrinsyc cerfBoard? [intrinsyc.com] It's small, got an ultra-low-power StrongARM CPU, PCMCIA for 802.11, and runs Linux too.
Just to clarify (Score:3, Informative)
We did try the thing with X10-wireless cam which is what got us started on this whole thing. It was TONS of fun but the problem was the X10 cam gets a pretty poor quality picture when the car is moving and bouncing around.
First, think bigger... (Score:1)
It doesnt have to go fast.. just needs plunty of power, besides what kind of refresh rate do you expect from the cam?
Just think... throw a tv up on there.. design some kind of arm thing to hold the camera and manipulate... and run it around the office playing I spy..
Even cooler idea for the remote cart... those interesting buisness meetings... Drive the cart into the boardroom and then display your presentations from it.
After you have figured out how to get the control down, discovered what problems you had, and what other implementations you would need to miniturize the operation.. then, and only then you can even try putting that crap on a rc car...
BTW... I dont think you could control my rc monster truck via WIFI.. the thing can go 30mph and uses nitros for fuel.. I love doing donuts on outdoor basketball courts.
DRACO-
Muffins (Score:3, Interesting)
Why 802.11 (Score:1)
AN easier way?? (Score:1)
Small Embedded Computer with 802.11 for RC Car? (Score:1)
Embedded == PC104 (Score:1)