PDA

View Full Version : Rewiring videogame controllers



dejaentendu1416
2008-Apr-03, 10:43 PM
I figured I'd throw this out there in case anyone here had a clue and was willing to help...

I'm a senior in high school, and my school has a club which participates in the Sea Perch competition, co-sponsored by Drexel and the Naval Department. The basic premise of the competition is, given a basic kit (pvc pipe, some wires, three motors - two for propulsion, one to move up and down - and switches for a VERY BASIC control box - each motor can be turned fully on forward or reverse or off) and a $15 budget, each team has to build a "submarine" that can navigate through a course and collect a "load" (aka pool rings).

We've built the basic control box, buuut, we'd like to be a bit more adventurous. One idea was to get a cheap old playstation controller or something of that sort and rewire it to serve our purposes, because having the joystick would give us A LOT more control. Problem is, we have no idea how to go about it. My physics teacher runs the club, but, he knows absolutely no electrical engineering (as in, he was confused when I suggested using a potentiomenter to even out the engines), so he can't really help us. Actually, he told us today that there was no way we'd ever be able to figure it out, so now we're all determined to prove him wrong haha.

Regardless...if anyone has any suggestions, or any good websites to recommend, that would be awesome =].

Neverfly
2008-Apr-03, 10:51 PM
The problem with the playstation controller is that it operates on the commands from the system.
You can't just splice the wiring and make it work.
You could gut one and use the BASIC components but for all that work, you may as well just build your own controller and reduce the confusion.

ETA: You might consider going to Fry's Electronics ( Or a similar store- like Radio Shack) and looking over the specs on Generic Joystick style controllers.
Those tend to use moderation in control independently (Like a dimmer switch- so instead of forward at full power or dead stop- it moves it like an accelerator) and see if any of those could be a possibility.
I say Joystick style because they tend to have all the electronics needed in the controller already (It's why they are usually a lot bulkier).

dejaentendu1416
2008-Apr-03, 10:59 PM
I was afriad of that.

If we were to try building one, would it be possible to keep the cost under $5-10 (just for the final parts, not whatever tinkering we do and screw up - we only have to account for what's actually used in the budget)? (The playstation idea seemed appealing because someone apparenly saw them for a buck or two at GameStop or a similar store)

EDIT: Just saw your edit haha. I'll go take a look at their website and see if they've got anything that looks useful. Even that would be better than simple on-off...trying to manuever the thing right now is a huge pain in the ***.

Jay200MPH
2008-Apr-04, 01:02 PM
It depends how much control you want. Some of the early ones were REALLY basic but you don't get anything fancy like analog directional input or pressure sensitivity. A C-64 joystick (http://www.syntaxerror.nu/joy002.jpg) for example has just five electronic switches - four directions and one button (the second button is selected mechanically - it can't read both at the same time!) - and uses an industry standard DB9 serial connector which you can get anywhere. You can easily make one do anything you want. I'm sure you can find the pinout using your favourite search engine.

Probably a lot of older gamepads are similar in nature (Amiga, Atari, Sega Genesis, etc.)

- J

Neverfly
2008-Apr-04, 01:04 PM
It depends how much control you want. Some of the early ones were REALLY basic but you don't get anything fancy like analog directional input or pressure sensitivity. A C-64 joystick (http://www.syntaxerror.nu/joy002.jpg) for example has just five electronic switches - four directions and one button (the second button is selected mechanically - it can't read both at the same time!) - and uses an industry standard DB9 serial connector which you can get anywhere. You can easily make one do anything you want. I'm sure you can find the pinout using your favourite search engine.

Probably a lot of older gamepads are similar in nature (Amiga, Atari, Sega Genesis, etc.)

- J

The trouble is that pressure sensitivity is what he was looking for.

Jay200MPH
2008-Apr-04, 02:22 PM
Well, what would be needed is a "dumb" analog controller that doesn't "communicate" with the computer (i.e. no 2-way data transmission.) The only input line to the joystick is 5V to power the thing. I believe older (pre-USB) joysticks for the PC and Amiga work like this. Positions on each axis are sent as a variable voltage to one of the pins on the serial port. Remember how you would have to "calibrate" your joystick every time you played a game? This was to allow the computer to read the absolute range of output voltages along the analog axes so it could determine how far off center the stick was.

Shouldn't be that difficult to wire up for your application.

(What kind of high school physics teacher doesn't know anything about electronics?)

- J

HenrikOlsen
2008-Apr-04, 02:45 PM
Well, what would be needed is a "dumb" analog controller that doesn't "communicate" with the computer (i.e. no 2-way data transmission.) The only input line to the joystick is 5V to power the thing. I believe older (pre-USB) joysticks for the PC and Amiga work like this. Positions on each axis are sent as a variable voltage to one of the pins on the serial port.
They where actually even simpler than you seem to think.
Just a potentiometer.
The gameport then had a capacitor discharge through the pot and the position was determined by the time it took to flip a smith-trigger input.
Total component cost for a 4 input AD converter:4 capacitors and one I/O chip.

TrAI
2008-Apr-04, 02:54 PM
Well, you may be able to get some of the old style PC joysticks with 15 pin d-sub connectors, many of these have analog control by the use of pot-meters, this page (http://www.allpinouts.org/index.php/PC_Gameport) seems to have pinouts and some other interesting info.

Of course, if you can find a modern USB stick cheap, you could just take it apart, the basic functioning is the same as the older types, pots and switches, just with the addition of a microcontroller and some other supporting electronics.

dejaentendu1416
2008-Apr-05, 12:11 AM
You know, I swore we had one of those old joysticks lying around still, but apparently someone decided that it would be a good idea to throw it out...I mean come on, who throws things out just because they're outdated and seeimingly useless? People these days...

It's a shame, I wanted to play with it a little. Oh well, now I just have to figure out where to track down another one. If I can, though, that actually looks relatively plausible, I think.

Now, first off, I want to apologize for my complete ignorance, buuuuttt...how exactly would I go about wiring the thing to the three motors, given a pinout like the one you referenced? I really have no experience with this type of thing, unfortunately =\.

By the way...my physics teacher is actually a pretty smart guy, he knows what he's doing and teaches it well, but, he was a chem major, so...he has his moments =P.

Neverfly
2008-Apr-05, 12:23 AM
http://www.wopba.com/controls.htm
Here's a quick peak at DIY website about a particular topic- I would invite you to play with the search function and see what you can find.:)
http://www.diynetwork.com/diy/hb_radio_control_models/article/0,2033,DIY_13885_2370259,00.html