LPT Switch

[brained]

your right, but remember to get yourself a multimeter to ensure things work ok.... or simple makeyourself a poormans continuity tester to ensure that the wires go to the desired pins.......

[Hoagie_one]

i got a multimeter.  I just labeled all the pins backwards because i didnt realize teh diagram shows the back of a computer and not the connector.  Mirror image of what i wired.

This also explains why some contacts worked and others didnt, because i inadvertently rigged up proper connnections by reversing the diodes.

oh well.

[brained]

jeez!! :S.... that's why I didn't used a hacked printer cable. I built just everything from start. Remember that DB 25's have the pin labels, you must look close to avoid mistakes... 

[LordDamo]

jeez!! :S.... that's why I didn't used a hacked printer cable. I built just everything from start. Remember that DB 25's have the pin labels, you must look close to avoid mistakes...

Is it possible to use a hacked printer cable though? I was thinking of using one to save on the soldering. Im not a wizard at it, so I dont enjoy too much of it in one sitting.

Anyone know any good soldering tutes? LOL

[Hoagie_one]

im using a printer cable, it'll work fine....as long as you get your pin #'s right, lol

I butcher all my soldering BTW.  Big globs of metal goo.  nothing asthetic here.

[LordDamo]

So, I look at the plug from the side that the cable is <b>not</b> on to work out the pin numbers from the diagram?

Or is this round the wrong way? I just want to be REALLY sure, cause i'd probally do the same thing as you hoagie.

[Hoagie_one]

http://www.loop-back.com/rs232_std.html

diagram at the bottom has it listed weather you are looking at the male or female pins

i had it backwrads

[LordDamo]

http://www.loop-back.com/rs232_std.html

diagram at the bottom has it listed weather you are looking at the male or female pins

i had it backwrads

Ahh, that makes it much clearer for me, thanks for the link

[brained]

anyways, DB25's have the pin numbers in the front, if you look closely you can see them.... that'll save you a lot of mistakes

[mame-guru]

Wow I should have told you guys about this before.

I originally used a keyboard encoder (see pic) and a mess of wires to send the inputs to my mame acrade machine. I found the LPT-Switch and made a small circuit board (see pic) to allow all 60ish of the inputs to be availible, in case I wanted to add more stuff later.

The board is the type that has holes in it but no tracks, cheap from most electronics shops. The header bloacks are 10 pin types that used to be used for the serial headers on motherboards.

The work took some time but was worth it in the end. As I have already added some extra features, keys, which would have been a pain in my keyboard encoder days.

Now my next project will be an LCD screen that displays the button configurations, start screens, etc of the game (need suitable multi monitor interface); and/or some nice voice recognition to select games from the menu (limited success so far, using XP's voice stuff).

[Hoagie_one]

yours looks alot sexsayer than mine does.  but as long as it works, im fine with it.

[quarterback]

I found the LPT-Switch and made a small circuit board (see pic) to allow all 60ish of the inputs to be availible, in case I wanted to add more stuff later.
...

Now my next project will be an LCD screen that displays the button configurations, start screens, etc of the game (need suitable multi monitor interface); and/or some nice voice recognition to select games from the menu (limited success so far, using XP's voice stuff).

Cool.  Keep us updated on your projects, and welcome to BYOAC!

[Trimoor]

I don't suppose anyone can get this working on a non-windows system yet?

[Hoagie_one]

I don't suppose anyone can get this working on a non-windows system yet?

I just built a snes type circuit parallel switch for dweebs0r.  He said he has a way to get it to work under linux.  May want to ask him what prog he's using.

[Hoagie_one]

Well, I finished re-wiring this tonight, and all teh inputs register correctly.  If I find time tomorrow, I'll rig up a street fighter panel with the LPT switch and see how well it works out.

[Hoagie_one]

Rigged up a street fighter panel and it works great.  Smooth response.

I now just have to test the switches that share a common wire to see if there is no interference.  I dont expect there to be because each input registers separatly, but i wot be sure till i put it in a play test.

[Trimoor]

Anyone out there willing to port the software to DOS or Linux?  I really hate windows.

[Hoagie_one]

Good luck with that....wish i could help ya there.

[brained]

Hoagie, Did you test the interface?? how it went?

[Hoagie_one]

I just have a couple more tests to run on it to be 100% sure of it, but so far, It works perfectly.

[Hoagie_one]

Well, I've done everything i can think of except hook up 60 buttons and hit them all at once.  This thing works great.  I'm just going to neaten up the wires and probably sell it on the buy\sell board.

I dont really need 60 inputs.

[cholin]

If its for sale, how much would it be?

[Hoagie_one]

$35 shipped.  That covers all the parts and some of the time I put into it...just to see if I could do it.

If anyone is interested, let me know.

[cholin]

US im assuming?  You should take a few pictures of how you built it too, it would make a nice tutorial

[Hoagie_one]

I drew up a picture of how the connections work.

http://www.susans-spot.com/LPT_Diagram.JPG

[Gamecab]

Hey,

If I can get enough people interested in this than I can make a circuit board and send out to have a few (Say 25+) produced.  I read this thread today at work and have been thinking about this for the past 5 hours. 

Let me know if anyone is interested, I'm just looking for another fun PCB Project to play around with. 

Also - In order to keep this board as cheap as possible I would say that the buyer would have to buy and install all of the diodes, screw terminals and 25 Pin connection on their own.  At that point I think the boards would only sell for about $5 a board.

Thanks
Charlie

[Hoagie_one]

what would be on the board because thats all this switch is..is diodes, screw downs and db25?

[Trimoor]

The circuit is so simple I don't see how a PCB would facilitate construction.  Then again, if people buy your LED driver board, there must be a market for it.
You should probably include the DB-25 header.  They can be difficult to find.

I have started on a Linux driver if anyone cares.

[Hoagie_one]

I have started on a Linux driver if anyone cares.

awesome

[Crazy Cooter]

I have started on a Linux driver if anyone cares.

When did we start spelling DOS
L i n u x ?

One of these days I'll have to pick up programming again.  Where's my box of punch cards...

[Trimoor]

Punch cards? Slow down there, fancy boy!  Back in my day, we had to hire a bunch of foreign kids to remember a set of numbers, and type them in real fast when we poked them with a pointy stick.

It worked great until one of the kids got electrocuted by the conveniently placed bare power cable.  I kept poking and poking, but he wouldn't move.  Eventually I got bored and left.

[Gamecab]

The circuit is so simple I don't see how a PCB would facilitate construction.

[Hoagie_one]

im interested in seeing how it looks.  Hey even if you manufactured the board with diodes, I gotta think it will be 60 inputs on the cheap. 

[brained]

I think you should sell the whole kit!! board, diodes, cables, hookups!!

*edit* spelling

[Hoagie_one]

I think you should sell the whole kit!! board, diodes, cables, hookups!!

seriously, might as well make some cash.  These things work fine and for the cost, its gotta be beter than buying an ipac4....cost wize that is.

[Gamecab]

Ok,  You twisted my leg, I'll do it.  I'll let you guys know the rough prices tonight/tomorrow for just the kits.  I just needed a reason to order a board for myself too, but paying $90+ for a single board was just too much money.  The unit cost of 25+ boards is drastically cheaper.

[cholin]

Yeah buying in quantities is better because the company charges you mostly for the designing and silkscreening of boards.  If you have an order of 25 boards, they already have the silkscreen and solder layout ready, so they just produce another copy.  If one board's screening development is $15 then all of the board are usually around $20.

I did alot of research on this as I wanted to develop my little LED driver board (its not what yours is) but once I got down to finding the market and drawing the board out, I got lazy.  I spent a few hours drawing but I can't fit the parts in reasonably without solderring wires all across the board because each input needs two outputs   Where do you get these boards done?

[Hoagie_one]

Ok,

[Gamecab]

Ok, After a few days of smacking my head against the keyboard I was finally able to produce a LPT board that can use 40 Switches.  I'm shooting for another design to do 60 or better but I'll have to read up on that.  The board itself looks like a web that a drunken spinder may have made after 3 days of playing Maze Craze  .
The boards and all of the parts would come out to around $20 as a sellable kit.  Personally I know you can buy a key wiz for around that price but I just had an itch to create this board.

So my questions are:
1. Do you guys think a market may exist for an LPT board?
2. Do you think an LPT board will perform better than a Keyboard encoder type board.
3. Do you think it's worth it to move forward on production?  I feel like it may be a gamble as I need to order at least 30 boards to get an OK price.

Let me know.

Thanks
Charlie

[Hoagie_one]

as far as i can tell, the thing worked great.  but economically, if its not 60 inputs, there are better alternatives.  If you can get teh 60 inputs at $20, or there about, then its worth it, but for 40, I'm not so sure.