Solid State Metal Pad - Any interest?

[blue-kun]

What system? ' o')a

Eugene
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[intrest86]

I'm assuming you saw one of the QProx systems used at some time in the past

The specifics of the system would help me determine if I am going down the wrong track. Right now my response time (the longest period of time you can hold a switch without response) can be as low as 49ms (49/1000 of a second). If that is not good enough, I can get it down to 5ms (5/1000 or 1/200 a second). In the extreme case, it could be lowered to 3ms (3/1000 a second). I would thik that all of these times would be nearly impossible for a person to distinguish as anything but instant, especially since it takes time to push a button down too.

But arethese times not good enough? Advice is always helpful.

[blue-kun]

Oh, no, I was just doing some research at that time. =)

About response time, just keep in mind that adjacent 8th notes of MAX300 are only 100ms apart. My guess is that the latency would be okay if you could keep it under 30ms or so.

Eugene
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[Soypancho]

Although it may raise the cost a little, I think it would be important to make the arrows physically different in some way from the rest of the pad. For the arcade feel, the best way is to probably have them lower. I could only afford one metal pad so for doubles I use my BNS next to my modded 3rd party mat. One of my huge issues when I end up on the mat is that I can't distinguish the edges of the arrows as I can on my metal pad, or in the arcade. Another option to consider is to just border the arrows with like a half inch of either the same material, or maybe a different, rougher material with more grip. Just a thought, I really hope I could be of some help as I'm definetly gonna be building my own if it turns out well.

~Pancho
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apparently I'm doin this all wrong. care to help?

[intrest86]

This first time there will be a difference between the arrows and the rest of the pad. The arrows will be a slightly lowered panel of plexiglass, and the rest of thepad is compose of metal wrapped wood. The solid layer of plexiglass board is just an idea for the future

blue^: Any idea the exact smallest degree of error you are allowed on Max300?

[blue-kun]

No, I don't. I think you'll have to experiment with GameShark or some other automatic input tools (which I don't have at hand =p).

Eugene
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[intrest86]

Lol, neither do I, I play with StepMania >_<

O well, I'll just test it out. I know I can get under 30 if I need to, so no worried

[blue-kun]

Um, actually you may want to ask the programming staff of SM and DWI for more timing information; they are the one who should know the most about timing technicalities after all, next to Konami people themselves =p.

Eugene
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[intrest86]

Will do, will do

As soon as I can get home, that is. Stepmania.Com is being filtered >_<

[intrest86]

I was able to hunt down the required timings on DDRManiaX for a Perfect:

DWI: 50ms
SM: 45ms
Arcade: 35ms

With the 50ms sensor I have in the mail right now I can at least do a proof of concept. With some fancy Calculus number crunching, the probability of any combination of the sensing circuit error (Me, or MaxError) and the window the game allows (W, ie DWI's W = 50ms) comes out to:

(2W-Me)/(2W)

So with the circuit in the mail (Me=50ms), the probabilities come out to:

DWI: 50%
SM: 44%
Arcade: 29%

However, with the minimum error (Me=5ms), the probabilities come up to:

DWI: 95%
SM: 94%
Arcade: 92%

Of course, the earlier in the window you press the arrow, the higher the probability of it being correct.

On the other hand, it takes time to press an arrow button down, so it to has an Me>0. I'm not positive, but I imagine it takes longer than 5ms to press and depress an arrow on a normal pad.

Lol, I'm rambling . Last time I checked, the package with my electronics in it was in Montana, so I'll be able to test this stuff out on Monday if all goes well. Thanks for everyone's input

[intrest86]

So, I have been thinking about the design issues, namely timing, a little more. I have two choices:

1) Use a slower chip (30ms), but the chip could be accessable by anyone who wanted to copy my design and build it on their own. The timing would be rough yet acceptable.

2) Use a much faster chip (2-5ms), but the cost of hardware for programming the chips would be prohibitive ($50-70 for the programming equipment). In that case, it would seem like a worthless idea to even consider releasing directions. However, the timing would be wonderful, and may even be faster than a standard design.

So, the trade-off is responsiveness vs ease-of-building. Which do you think I should go for?

[blue-kun]

I'd lean towards faster chips. 30ms is not something most perfect attackers would accept IMO.

Eugene
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[intrest86]

Update time:

I got the componenets in the mail today, but I should have looked at the dimensions of the voltage regulator >_<

Anyway, I won't be able to test it out perfectly on my solderless breadboard because the regulator is just to darn small and I need to use a circuit board in place of wire in a lot of places to get better reeadings. I did plug what I had into my solderless breadboard, wire it up, and get at least a glimmer of hope that it would work out. Main problems are the digital sags in voltage from switching LEDs and the wires going everywhere and disrupting readings.

I'll get some PC Board at Radio Shack tomorrow and fasten everything down. Then I'll get you all a picture

[TheManOfTheSea]

Can't wait! (Thank god for Electronics class, I at least understood SOME of that...XD)
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[Plautus]

Pardon my ignorance; I'm trying to understand how this might work.

Is the response time fairly constant and predictable? That is, does a 50ms maximum response time mean 50ms every time, or do the deviations get much higher with the maximum response time? I'm asking because I think the point about the time needed to press the button is a valid one; that is, that when a PAer is doing MAX 300, he doesn't consciously figure the amount of time it takes to push the button, it's already accounted for in his technique. So it may not be the response time closest to zero that you should be looking for, but the response time closest to that of an arcade pad.

BTW, I am not the one you want to fine-tune that measurement, but if you make this work and detail your work, you can bet I'll try to make something like it!

EDIT: OK, I now see that 50ms is the maximum error measurement. Still interested in seeing your soldering work tonight

[intrest86]

Lol, you got it

Every 50ms the circuit checks to see if an arrow is in contact with something. So if you put your foot down, it will be sensed the next time the circuit cycles through that arrow.

[blue-kun]

[intrest86]

Lol, time for a brutally honest update

It is taking me a lot longer to solder this than I thought, mostly because I am taking my time and thinking about every single connection, wondering if I am doing this right >_<. I already burned out 2 LEDs, and that is just because I was wondering how bright you could get them an dswitched them up a little too high... stupid me.

We'll see how this goes, it is quite possible that after this step I will find out that it is quite impossible for me to get this to work. Heres to luck

[tolookah]

hey, even if you dont get it to work, could you post your results and design notes? im an EE student, so i may even be able to figure out your problem/resolve it, and im sure others are interested in what you did too, so if they think of the same path, they could see what problems arose and stuff.

[Catastrophe]