Computer control of an Epoch racer

[dr_joe]

I've managed to put my Epoch racer under computer control. The computer controls speed and steering via a parallel port interface to the standard controller. If you'd like to learn more, installment one - modification of the controller - is posted at http://dr_joe.home.isp-direct.com/

[LBRC]

:D , will have to give it a try. Thanks for posting it here.

[dr_joe]

I've managed to put my Epoch racer under computer control. The computer controls speed and steering via a parallel port interface to the standard controller. If you'd like to learn more, installment one - modification of the controller - is posted at http://dr_joe.home.isp-direct.com/
The description of the circuit I use to interface a computer's parallel port to the modified controller is now posted as well.

[honda_s2000]

WOW, ok, so let's say, I'm an average guy, who's never done any robotics, programming or anything of the sort, but I can solder, and have a good knowladge of rc cars and vehicles...how hard is this going to be ? I'd really love to try this, and I have alot of spare Epoch controlers... (about 3/4 spare) that I'm willing to try this out on... I'd just like a little more info on the following.

Difficulty for me (position explained above)
Connection to my computer, will this connect to a regular home desktop PC without any modifications ? what sort of plug(s) will I need for this to work ?

I really love this idea, and really want to try it out...maybe a better way is to contact you by email ? I'll send a copy of this post to your email too :)

Many Thanks,
Joe

:D

[dr_joe]

All I can say is review what's on my site; it's as hard as it looks. I try to give a pretty detailed description of what I've done. To date it's been mostly some very basic electronics - wiring together some fixed and variable resistors - and hooking it up to a computer through a standard parallel printer cable. No modifications need to be done to the PC. If you have a parallel printer already hooked up to your PC, you just have to disconnect it when the car circuit is connected. Any PC will do. I pulled an old portable out of the closet that is still running Windows for Work Groups 3.11.

The next phase is software. If you've never done any programming, then it will be a learning opportunity. But, again, just to get the car moving under computer control does not take a lot of sophisticated programming. Basically all the software will be doing is manipulating the speed and steering controls. The software I've written so far uses TrueBasic - no machine code - and is pretty straightforward. Basically, you put in a sequence of speed and steering settings, and the computer executes them. I'll write a bit about the software in my next installment on my site, probably in early February. (I'll be busy next weekend watching the Bears crush the Colts.)

One thing I have discovered so far, and this may help you decide what direction you want to take, is that the Epoch system is not as linear and repeatable as I had hoped. I expected, for example, that car speed would be a fairly linear function of the speed potentiometer. Well, it's doesn't seem to be. At some intermediate speeds, the car actually slows down as the pot is increased. Using feedback, a human being deals with this pretty easily, but it complicates computer control. Also, there's a lot of variability in the system. Running the identical program multiple times doesn't result in the same behavior. The distance traveled varies as does the amount of curvature in the turns. So if you were planning to put something together that you could take right out to the track, you might be disappointed.

[epoch1-43]

This is seriously cool dr_joe! :) Please keep us abreast of developments. May we publish the final write-up on our site? Thanks! :)

[dr_joe]

Thanks for the compliment.

This weekend I added a software section to my site, and for now that pretty much wraps up where I was going with an unmodified car. It may be some time before I get to the point where there are actually some smarts on the chassis, so I guess the current state of the site constitutes a "final write-up".

I'd be more than happy to let you publish the whole thing here. Let me know what I need to provide. Also, if you see the need for some polishing, let me know.

[epoch1-43]

Awesome! Can we just lift the content from the site directly? Thanks!!! :)

[dr_joe]

That would be fine. If you need anything else, let me know.