My home built metal DDR pad (Part IV)

Pyro.699 · Basic Member Joined: 08 Dec 2005

Hello,

I have spent the last 4 nights experimenting with making my own DDR pad!

Countless wodoen modlles have been made, attached to led lights.

Now, i have the complete clockwork down to one thing. I want my pad to be strictly USB 2.0.

QUESTION:

How do i mkae my computer reconize the signals coming out of my pad!
(please dont say vga programming, i dont want to get my books out! lol)

Any really simple way?

Thanks
~Cody Woolaver

marcan · Trick Member Joined: 28 Jul 2005

The simple way: buy a digital USB gamepad and connect the pads to it. You usually need switch outputs with a common ground and NO current on open switch (depends on the IC on the gamepad you use, but having some voltage in there while the switches are open is unsafe if you don't know the specs). Refer a few pages back if you use lights for a simple and safe circuit to use that I posted (diagram included). Summary: you need an NPN transistor for each switch - any common signal type is fine, no need for power stuff. e.g. BC547 is OK. light (-) to power supply (-) and transistor emitter, light (+) to the specific switch wire and to a 10Kohm resistor which is itself connected to transistor base, the common wire for all switches to power supply (+). Transistor Collector to the switch on the USB gamepad, and make sure you tie the gamepad's ground and your pad's ground together.

The hard (but very powerful and awesome way), which is what I used: build a digital USB interface circuit yourself with a USB connection and a PSX pad connection, with support for PC USB and XBox pad USB (and PSX pads via PSX port), with programmable lighting support and an LCD screen for configuration. Nice thing is you can set the lights to come on when you step, OR when you are SUPPOSED to step (stepmania has an option for that). Of course, you need at least some basic knowledge of electronics to get this to work, and programming skills for the microcontroller (but now that I've done all the work I suppose you can skip that

)

Been messing around with lighting. Current prototype, which will probably turn into the final thing and which I like a lot from my testing, looks like this: medium-thickness plexi with three edges painted solid white. Fourth edge has a CCFL lamp running alongside it. Bottom is painted thin white, and topped off with aluminum foil to catch stray light. Aluminum foil around lamp reflects all light into the acrylic. Theory is: light enters the acrylic and bounces around between the top and bottom due to total internal reflection (i.e. like an optical fiber). Edges reflect light back in (possible idea: replace white paint with aluminum foil and test). Paint on bottom inhibits reflection and catches light, diffusing it upward onto the arrow graphic which sits on top. A piece of thin Lexan (which is a very poor transmitter of light BTW - plain acrylic is way better which is why I used it underneath) is placed on top to protect the arrow graphic.

It looks like this (excluding the arrow graphic and top lexan):

The lines represent different paths the light could take. Grey is aluminum foil, white is paint, the circle is the CCFL tube. Paint is present on the edges near and far away from the "camera" in that view, but I don't show it since it's a cut-through view.

Light reflects off the sides of the acrylic only if it comes in at an oblique angle - that's why you need paint on the sides, and why the light from the bottom shines through (Indeed why you can see through acrylic at all - light has to already be INSIDE the acrylic and entering at a shallow angle to be reflected off. This is why you can't see outside of the acrylic if you look into it from the edges, and why if you shine a light into an edge all the other edges light up)

This is the lighting method that laptop TFT screens use too.

Of course the light is brighter near the lamp. In fact it is also brighter on the other side due to the reflection from the edge - the middle is darkest (but still reasonably lighted). I'm considering creating a pattern of paint on the bottom to compensate. Where there is no paint the light doesn't come out, so the light would be better distributed. Also I will not paint the bottom where my arrow graphic has large areas of black - it would waste the light.

Photos to come! It looks real neat. I think this CCFL tube is also not that bright - others I've seen are too bright to look at and this one definitely isn't. I'll be ordering a set of tubes soon, and see if I can build a powerful inverter to run them (I'll need four).

marcan · Trick Member Joined: 28 Jul 2005

I made a neat block diagram of my pad circuitry. Completion of the pad (with basic firmware, which will improve over time) is in sight

Click image for a larger version

I'll set up a page with information and photos of the build process soon. Camera being fussy about the connection to download the photos now :\

HitokiriX · Trick Member Joined: 27 Mar 2004 Location: Berwyn, PA

Now THAT my friends could possibly be the most sophisticated DDR pad ever created up to date. It's probably just me but I don't understand most of it, especially the four arrow panels in a row with lighting to the left of it. Chances are I'm just reading the diagram wrong or something, but w/e. I'd never be able to build a monster like that anyway. If you could build those and sell em....what a killing that would be.

marcan · Trick Member Joined: 28 Jul 2005

Hey, thanks!

The diagram just looks all hi-tech and all, but it's really not *that* sophisticated. It's not to scale or a diagram of the real thing, just a layout of how the things plug into each other (except power, which goes just about everywhere and which I omitted). The pad looks just like any homemade pad, except it's quite thin (somewhere around an inch), and it has a 15-pin plug on top, four control pushbuttons, and light tubes around the center square (one for each arrow panel). The control box is just a dull grey box with an LCD display and buttons, and lots of wires inside.

Pyro.699 · Basic Member Joined: 08 Dec 2005

Wow, that did make sence, nice diagram!

Umm, do you think you can explain each part abit more? like where each individual whire goes?

Like, what cards do we need? and where do we plug the four whires from the usb to the card?

My most confusing question, is where do i get this card? and how much?

Thanks
~Cody

marcan · Trick Member Joined: 28 Jul 2005

All boards and electronics are homemade, except the LCD module of course (that is just a standard Hitachi-compatible character LCD, 4x20 chars). The main control board is actually quite simple, since the microcontroller does most of the work. It's just the microcontroller, a lot of connectors, a bunch of resistors, and a few other things. You could build it yourself onto a prototyping board if you wanted, although I made my own custom PCB. I'll upload the layouts. It's not hard to make your own, it works kinda like home-made B/W photo developing, except instead of a photo you get a board. All electronics are thru-hole and the board is single sided, so it's just about as simple as you can get.

Most of this stuff is modular - if you just want to build a controller board for a regular switch-based pad with light support and only running from USB it's much simpler - only the microcontroller and a few extra things, and you don't need amp boards or anything else. If you just want a digital pad with only PS2 support you can even do with a much simpler (and cheaper) microcontroller, and almost no extra components.

Anyway, camera's behaving now

here's a bunch of photos. I've removed many of the during construction ones - I'll have all of them once I finish on a webpage detailing the process.

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An amplifier board

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The top left and top right panels, with holes for the control buttons

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The hole for the data connector to the pad (on the top left edge of the base)

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Soldered cables to the connector, and screwed into place

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Connector for top-left control buttons

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Top-right control buttons and connector

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Routing cables underneath top-left, and setting up amp board in place

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Temporary test rig, with a power supply. Note I added a power LED between the top left control buttons

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We've got power!

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Now that I've soldered the other end of the cable, how about testing it through the control box electronics?

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Yep, it works! (read the text in the LCD display

- and that's without the nifty animation!)

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Middle square setup

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Mockup of lighting solution. Looks pretty good!

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Pad with non-sensor squares in place (not screwed in yet), and edges of sensor squares glued onto the base. You can see the bottom sensor wooden panel - the sensor's underneath.

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Testing the lighting system - looks good!

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Top half of the control box - you can see the LCD, the buttons, and the pad connector

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Bottom half. Top-left is the PS2 pad connector (here plugs in a cable with the real plug on the other side), and on the right you can see (top to bottom): power selection switch, external power input, USB connector. You can see the board (that big chip in the middle is the microcontroller).

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Board by itself. Notice most of it is connectors! You can see the adjustment trimmers (left are for the analog inputs from the sensors, and right is LCD contrast adjust), the four lighting power transistors standing up in a row, the microcontroller, and the voltage regulator next to the USB port (flat with a screw). The rest is: capacitors, quartz crystal for the microcontroller, resistors, and two signal transistors.

IMG_0906_s.jpg

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Bottom side of the board. With lots of last-minute fixes of course

So there. It's getting close to done

I could've sworn I had more photos of the middle square and the sensors though :\ dunno where they went.

vesper · Trick Member Joined: 06 Dec 2005

I'm having some trouble with the wiring, and since the above posters seem to know what they're doing I think I'll give it a shot asking here

Each wire connects to one of those black pads at the bottom, with the big center one being the ground. I used electrical tape to hold the wires down, but this doesn't work. Depending on how I hold the PCB, sometimes the buttons will register and sometimes it wont.

What should I do to hold the wires down? I was thinking of soldering them directly to those black pads, but there is a sticky adhesive-type goo covering most of them. Am I supposed to clean that off with Windex or something? Any ideas are appreciated

marcan · Trick Member Joined: 28 Jul 2005

scratch off the black until you get to copper, and solder. Or scratch the traces that lead to each black area (the green varnish there is quite thin) and solder there.

vdl · Basic Member Joined: 30 May 2006

my wooden pad pics http://3priedez.net/dpad4/index.html
uses ipac controller and mini buttons.

i'll make detailed photos for next board.

vesper · Trick Member Joined: 06 Dec 2005

vesper · Trick Member Joined: 06 Dec 2005

I need to realign some of my corner brackets because the plexiglass was sliding a wee bit, but other than that everything works fine

Also, I seemed to have forgotten to add buttons for stuff other than up, down, left, and right, so I'll have to add some of those real quick too

Pyro.699 · Basic Member Joined: 08 Dec 2005

AWESOME!

Ok, one more request please ^^:

can you gime a full list of all the of parts requird?
like, all the cards, and whires... (i know the wood/metal and plexy glass...)
and an aproximate cost.
also, where did you buy all this equpment!

Thankyou verry much!
~Cody

slvrshdw · Trick Member Joined: 05 Jan 2005

first of all, thats GOTTA be the most advanced homepad ever built right?

marcan · Trick Member Joined: 28 Jul 2005

-Scorpion- · Trick Member Joined: 16 Feb 2005

You can overclock your USB rate using this tool:
http://www.majorgeeks.com/download.php?det=4469

Note that this could irreparably damage your Computer. However, I've changed a bunch of Computers to 1000Hz and never had anz problems.

marcan · Trick Member Joined: 28 Jul 2005

The Wise Fool · Posted: Tue May 30, 2006 4:45 pm Post subject:

-Scorpion- · Trick Member Joined: 16 Feb 2005

@The Wise Fool
This is awkward. The manual of the ITG I\O module states that the device is updated in an interval of 100Hz in isochronous mode, but then sends information in a 1000Hz resolution. If no button has been pressed within 10ms, no information is being send. I guess they did it this way to save bandwith!? I'll give you a link to the manual if I can find it again. Some AC distributor sold parts and had it on their homepage.