Wire length (with completed pics of CP)

[Wienerdog]

I'm building two stand alone controllers to play fighters.

[SirPeale]

Just for your controls?  Within reason, as long as you want.  Would't do like 100' or something, but ten feet should be reasonable.

[Wienerdog]

Yes, just for the controls, and the sticks are Suzo microswitch (fortunately not my p360s). 

Sounds good, I didn't know if there would be any problem with a voltage drop over those wires.  I might go 15 feet on each of them, but it's not like this needs to be "apartment sized".

[NoOne=NBA=]

I've heard RandyT mention 15' as the maximum several times.

I'm not sure if that's 15' TOTAL, including the run to the PS/2 port, or just 15' for the controller-to-encoder run though.

[Wienerdog]

Interesting, maybe I will go 10 feet on the Cat3 just to be safe. 

[RandyT]

I've heard RandyT mention 15' as the maximum several times.

I'm not sure if that's 15' TOTAL, including the run to the PS/2 port, or just 15' for the controller-to-encoder run though.

Heh, that's just me erring well on the side of caution.

I tried an extreme test one time by running one KeyWiz input to about 50' of 30ga Kynar (thin wire wrap wire) and it still activated the input every time without fail.  Now, this doesn't mean that 30 of these constantly modulating next to each other won't have crosstalk or other interference problems, but it did work over that distance.

So the rule is:  Shorter is always better, but don't go shorter than you need to until you know it will be a problem.

RandyT

[ShinAce]

Transmission speed is close to the speed of light, some 300 000 km/sec.

Assuming 60 fps, you'd need over 16 million feet of wire for each switch to lag by 1 frame. So technically, it might lag once you get over 8 million feet of wire. So obviously the length of the wire is not an issue.

However, shielding is important. The air carries a 60 hertz signal, EVERYWHERE, thanks to our power grids. So if you have 500 feet of exposed wire, you might pick up enough electrical noise from the air to cause problems. The only way to prevent it is to use shielded cables and shunt the shield to ground.

Personally, I'm working on a new stick that's connected to the encoders via monitor extension cable. I have 6 and 10 footers, which means I can get up to 20 feet of wire between me and the console. I've got a pair of headphones with a 16' cord. They sound great, and audio signals are much more flaky than digital signals.

[RandyT]

Transmission speed is close to the speed of light, some 300 000 km/sec.

Assuming 60 fps, you'd need over 16 million feet of wire for each switch to lag by 1 frame. So technically, it might lag once you get over 8 million feet of wire. So obviously the length of the wire is not an issue.

Actually it can be, but lag has nothing to do with it.  Wire has resistance,. Thinner wire has more resistance.  Long and thin wire has even more resistance.

Resistance can lead to voltage/current drop, which can lead to  improper operation of digital circuits.  Long wires, especially shielded ones, can also have capacitance, ringing and other nasty problems.

Like I said, shorter is better, but how short depends on the particulars of your installation.

RandyT

[cholin]

Well it all comes down to the wire he's using then.  Either way, if he runs 100 ft of wire from his Control Panel to his computer, he will still be fine, assuming the wire is straight.  Wire is made for this kind of stuff.  Sure, it might mess up, but thats after a while of abuse.

[ShinAce]

Even 30 gauge wire is only 1 ohm per 10 feet, and 30 gauge is ridiculously thin.

[RandyT]

I'd agree with your assessment if I hadn't seen a number of people here complain about problems with long wire runs.

There's theory and there's reality.  Theory says you should be able to go 100ft without a problem, but the reality is that long cable runs can cause difficulties, whatever the reasons.

Theory also says, shorter is always better when running wires for virtually any purpose .

Get a handful of PS/2 extension cables and see how many you can put together before your keyboard stops working   Not the same set of circumstances, but it will demonstrate some very real limitations to wire lengths.

RandyT

[ShinAce]

If you wanted a decent test, you should compare a 6 foot cable to a longer one. As soon as you add connections, it's an entirely different game.

[RandyT]

If you wanted a decent test, you should compare a 6 foot cable to a longer one. As soon as you add connections, it's an entirely different game.

Fair enough, try a  6' extension and a 20' extension.  You might even find that it works fine with one keyboard, and not at all with another.  That's why I say, don't sweat it too much until you see a problem.  But when you do, don't rule out cable length as a possible cause.

I personally had a problem going from a 6' to a 12'  wihen developing the KeyWiz.  I decided to test the Win2K box  on the other side of the room without trying to move my dev system.  I mistakenly thought I was experiencing an incompatibility with the OS.  Turns out  the dev system didn't like the extra length  of the PS/2 cable.  I moved  everything close enough to reach  with the 6 footer and it worked perfectly.  But not until I spent 2 hours trying to find a non-existent compatibility issue.

So I've experienced instances where cable length can make a substantial difference, but as with anything, YMMV.

RandyT   

[Wienerdog]

I've now experienced a problem with 12 feet of Cat3 on a test panel.  Controls seem less responsive on that stick.  Does that mean it's a length problem?  Probably not.  I would blame bad connections before I would blame 12 feet of wire. 

The 12 feet of wire worked good, I was able to run the wire behind the running microwave fine.  I did find out that I can live with a shorter run, so I'm going to switch to about 4 feet of wire, and I can put the encoder in the Player 1 panel, that all but eliminates any wire length concern.  Oh, I was just kidding about the microwave, my point was that there are many things to take into consideration, one of the biggest being how well the connections are made at the switch.  The main concern I was asking about was the voltage/current drop over that thin wire.  Interference is probably more of a concern. 

I'm not saying this problem was caused by the wire, but I was running Mame32 and clicking some of the buttons caused Mame to shut down and send me back to Windows.  I tried moving the buttons to different inputs on the Keywiz, but it was still happening randomly.

On a side note, are the default inputs set up to standard Mame buttons?  This was one of the original Key encoders.  I'm not sure where the disk is and I haven't looked around for any info.  The inputs on the board are marked 1-8 and A-P.  I'm down to the wire for putting these panels together, so any help would be appreciated.  I'm going to be handing this panel over to people with very little MAME experience, and I'm not going to be with them to help.  I'd like them to be able to plug this into a computer and go straight into games without changing configurations.  They will have a keyboard for coins and starting, and the two panels with 6 buttons each.  I know where to input the sticks, but where should I connect the 12 total buttons on the Keywiz?

Thanks for the help, this will save me lots of time.

[RandyT]

Email sent.

RandyT

[Wienerdog]

Thanks for the docs RandyT, that's what I needed.

As I mentioned, I went with a shorter wire between controllers (about 5 feet) and put the encoder inside the Player 1 stick.  I sure wish I had one of my new Keywiz Eco encoders, but I wedged in my original one. 

Shazaaam! is connected to the Player 1 and Player 2 start buttons in the upper left of the controller.

I used clear plexi for the bottom panel to show people what is going on inside.  I'm happy with them, I'm glad I used stain.  I almost went with paint but I knew I had to have the finish completed within about 8 hours so I stained and used clear poly on it.