VIA-based Mobile Robot Design For Download

An anonymous reader writes "This article at DeviceForge introduces the "PC-bot" -- a new mobile robotics demonstration platform design that is being made available for free download from Roboteq. PC-bot was designed to be highly flexible and extensible so that it can serve as the basis for a wide range of customized mobile robot designs featuring web cameras, motion detection software, and more. Details on the mechanical, electronic, and software design are available at Roboteq's website. Currently the bot runs Windows, but Roboteq expects that one of the first enhancements from the user community will be Linux support." Unfortunately, there's no way to download the RoboteQ motor controller the design requires -- that will cost you about $500.

Comments

Cheaper solutions

[baywulf]

If you don't want to spend the $500 and want a more affordable solution, try buying some surplus hardware. For example this page has stepper motors and controllers at reasonable prices.
http://www.alltronics.com/stepper_motors. htm

And instead of a VIA board you can get a cheap
80186 board for $69 from http://www.jkmicro.com/products/flashlite186.html

Okay you can't run Linux on that board but with 1 MB of memory and 33 MHz you can do lots with a robot.

Too bad VIA's ITX boards are SHIT for PM

[GoRK]

VIA's Mini-ITX boards might have low power consumption while operating but they are total shit for power management. They leave practically everything they can powered up even during S3 suspend when only ram is supposed to be fully powered. Even when totally powered OFF they operate USB, SuperIO, and PS2 ports at FULL power, no matter what the OS asks for, totally failing their own specifications.

The boards are capable of pulling up to 2A off of ATX 5VSB in flagrant overconsumption. Even if the power supply is capable of providing that current on 5VSB, providing it continuously without the internal fans operating (which they don't in suspend) could be dangerous. The ATX specification provides for an absolute maximum current draw way below what the average Mini-ITX board draws from 5VSB when idle or off.

This problem was identified over a year ago after the ITX boards were initially released; however VIA has never issued a single fix for it, although it's apparently not the hardware preventing the fix from being implemented! Needless to say, their customer support in the Mini-ITX department is also shit. Is it so bad to want the board to work as advertised?

Luckily, I haven't even gotten into the processor or video driver issues, which many people see as an even larger problem than the power issues.. To each his own :) At least VIA has some truthful advertising on one point: the board is indeed a very small 170x170mm!

~GoRK

Re:That's a good price for two 4KW motor controlle

[Animats]

This is a four kilowatt motor controller that handles over a hundred amps per channel. Those are big power MOSFETs. Probably, about half the cost of that box is the MOSFETs.

Driving them is non-trivial, too. You have to spend as little time in the linear region as possible, to avoid overheating. Yet the load is inductive and is fighting that. You need overtemp detection and current limiting. You need protection against H-bridge short-through. At kilowatt power levels, all that stuff has to be there. Somebody had to make that all work under adverse conditions.

Incidentally, motor controllers are usually run at a constant chopping rate but with a variable pulse width.

Take your $500 dollars and shove it up your..

[t0qer]

pockets. Save it instead, and build your own interfaces using parts from floppy drives, schematics on the web, ect.

Lately i've been rearing my ugly head at this page. The author has schematics for interfacing it to the LPT port, as well as software examples. I built my own interface using a rapid prototype board.

For those too scared to venture into building the interface themselves, I found this unit for less than $20 bucks from a company called ACS out in Florida. Unfortunately due to economic conditions, I cannot even afford that, but great looking product guys.

$500 is tooo much, i'd rather just interface steppers through the LPT and save an extra $380.

Can we say Overkill?

[Lumpy]

Unless the bot is going to do some image recognition or running advanced AI this is so overkill it isn't funny. Plus it will have a runtime that is insanely short for any real research to be done.

I made a "overpowered" robot 5 yearts ago with a baby 386 motherboard and the 1st generation wireless networking. and even with the AI I was messing with and basic image recognition on linux with a B&W quickcam, and I still had lots of processing power left over.

I was getting almost a full day runtime from the bot (depending on how much the motors were on. if you ran full tilt or worse started and stopped repeatedly you could kill the lead acid on board in 3 hours.)

and I spent ALOT less on my robot... including motors making my own motor controller and finding the 1st gen 802.11 wireless isa cards.

and they leave out important things like sensors...