Maker

My DIY Dance Dance Revolution Hardpad

IMGP0429Something like ten years or so ago, I built my own hardpad for use on Dance Dance Revolution and Stepmania.  Most of the pads that are easily bought are “soft pads”.  These vary in quality, I have a couple of pads that are pretty light weight and plastic I used ages ago.  These pads tend to get damaged pretty easily, especially when wearing shoes, and slide all over the place when playing.  When i used mine in college I actually taped it to the underside of the rug in the dorm and taped out the grid of squares on the surface, so I could play using my shoes.  I’m sure the people living below me loooove that.  Probably as much as I loved the people above me who played dice constantly.   Some more pricey are made of a thicker though still pliable rubbery material.  These mats slide around less due to the grippy nature of the material, but they can get worn out and damaged by the rough beating of shoes.

The ideal pad is a hard pad.  These can run hundreds of dollars on-line.  They also tend to be large and bulky and heavy.  Shortly after i had finished in college I decided to employ me newly acquired Engineering design skills to build my own Hard Pad.  The electronics part was easy.  I went to the local used game store and asked for the cheapest used PS2 controller they had in stock.  The guy behind the counter actually asked if I was planning to build a DDR pad with it, which was funny since I was.

The pad itself was a bit trickier.  I’d studied several design ideas on-line that others has built.  I wanted something that was less bulky than most of the pads I’d seen.  I also wanted to keep costs down somewhat, which meant using a little material as I could and not having to invest in a bunch of expensive triggers to wire into everything.  The trigger is the key component of course, since it registers the steps when playing.  The dead squares are all just plywood covered in sheet metal.

The sheet metal is also what I ended up using to build the triggers for the step squares.  When you press a key on a video game controller, all that happens is that an electrically conductive pad is flattened and shorts the connection between two copper pads on a PCB board.  When the electrical short is made,  current can flow which causes some chip somewhere to register the button press.  For my step pads, I simply enlarged this process by attaching plates of sheet metal tot he base and to the bottom of each step pad.  To give the pads some cushion and bounce, I placed strips of weather stripping bought at the hardware store between the base and the pad.  Stepping on the pad creates more than enough weight to overpower the weather stripping causing the two sheet metal pads to connect and trigger, stepping off allows the weather stripping to flex back up pushing the pad back to a neutral, unconnected position. I took some CAT 5 cable and soldered it to the sheet metal contacts and the appropriate parts inside the PS2 controller to replicate the button press action inside the controller.

Everything else was cutting wood, attaching corner brackets and attaching sheet metal.   Here are some old photos of the process.

The general construction was sound, but it had a few issues that I never really got around to fixing until more recently.

In the original design, I soldered the connections for the step pads tot he controller’s D-pad.  Mostly because the solder points were larger and easier to solder to.  This had some unintended side effects that made the game unplayable at any higher difficulty level.  By design, the controller never expects opposite D-Pad buttons to be depressed at the same time.  That is, it doesn’t expect the player to press left and right at once, the D-Pad generally controls movement in most games, why would you need to press opposite ways at once.  Dance Dance Revolution has “jumps” in more difficult stages, these are sequences where two arrows have to be matched at the same time, as in “jumped on”.  Since the D-pad doesn’t register left+right or up+down, these jumps would never register and were always considered a miss.  Kind of game play breaking in the case of DDR.

I also wanted to add a box to the set up, to replicate the buttons on the front of a real DDR machine used to select songs and options.  Not something important, but it would add to the effect, and if I ever got really ambitious, I could build a whole cabinet someday.

The other major issue, when I built the original design, I didn’t really do any real management of the wires between the controller and the pad.  They kind of strung around on the sides, they were all too long, and the controller itself was permanently attached to the pad, making moving and storing tricky.  I wanted to make the controller bits, detachable.

I’ve since solved all of these problems with some improvements, all somewhat related.  First problem was the triggers not working for jumps.  This was simple but tedious.  I needed to reqire the buttons from the D-Pad to the face buttons (Triangle, Circle, Square, X).  These work just fine when pressed together, lots of games have combinations where you have to press several buttons at once.

Please Parton my Shoddy Soldering

During this process, I also pitched the controller shaped housing and stuffed everything in a generic electrical project box.  I soldered the 4 shoulder buttons to 4 buttons attached to the box lid, to be used to interfacing with the menus.  Problem 2 solved, everything is in a nice box.

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The last bit was to make the controller easily detachable.  There are 4 pads, each with 2 wires, for a total of 8 wires going from the controller to the pad itself.  I was already using CAT-5 cable for the wire, it had 8 wires in it, so I attached an CAT5 end on the controller piece and a CAT5 receptacle to the dance pad.  Now the two were easily separable and securely attachable.

The ultimate test of course, does it all work?

stepmaniaresults

I’ve run several sets of tracks using the new set up and it certainly does work.  My DDR skill needs a lot of improvement to get back up where it was at my peak, but the pad itself works just fine.  Which is sort of the point, because it really is a fun way to get a pretty good workout in a short period of time.

 

 

OSEPP Arduino Starter Kit

Arduino and a Raspberry Pi 2BSo, a month or so ago, while traveling for work, I was bored in the hotel room and found out there was a Fry’s Electronics around the corner from the hotel. I decided to pop in and look around and see if I could find anything interesting. I also wanted to see how much Raspberry Pi 2B boards were there (and if they were comparable to Amazon.) They had a couple of Pis, a large selection of basic electronic components and a pretty decent selection of Arduino shields and parts.

I’d been looking into getting an Arduino for a while and decided what the hell. There may have been single packed Arduino boards but I really couldn’t tell from the cards which was the base board an which was just an add on shield. I ended up with the OSEPP Arduino Basic Starter Kit.  Honestly, since I hadn’t ever used an Arduino, I didn’t own an Arduino, and I had some basic but not super amazing electronics skills, this really was the best choice.

The kid includes a lot of nice basic parts as well as a guide book to get you started using these basic parts.  The box itself promotes the major projects of “Volt Meter”, “LED Game” and “Electronic Buzzer”.  It also runs through the basics of lighting up some LEDs.  The tutorials are decent though I wish there was a little more on the basics of how to work the bread board and the little wires.  It’s not hard to figure out, but it also isn’t super self explanatory if you didn’t have any experience with electronics at all.  the Volt meter tutorial is less exciting than hoped and the Buzzer just runs up the music scales but it could be modified to play a tune using the little piezo buzzer.

WP_20150630_09_21_48_ProThe LED game is neat, but simple.  You make the lights flash in sequence and you must press the button when the appropriate light is flashing, which causes the lights to flash faster.  There is also a 7 segment LED in the kid, which you make count down from 9 to 0.  This actually has a lot of fun potential and I have some ideas for it but I need to figure out how to light up both numbers to display a number (such as say, a temperature).

After exhausting the fun of the starter manual, on my next trip to the area, I bought a temperature and humidity sensor and wired it up.  This was a bit trickier since it required figuring out how to find and download the necessary libraries and modifying the code a bit to get it to read properly.  In the end, I managed to get things working though, which was kind of great since the AC in my hotel room didn’t have a digital read out, so I could know exactly how cold it was and why I was either freezing or sweating.

So, fast forward a bit more again, I’ve got some fun ambitions going and the idea of playing with several Arduino projects.  Unfortunately, while cheap, Arduino boards can add up to expensive.  Unless you buy cheap Chinese knockoffs for $3 apiece off of AliExpress.  I also have some cheap Network boards and temperature sensors coming.  Five boards total, five sensors and two network shields, for around $35, really isn’t too bad of a deal if it all works.

And thus, I have a ton of Arduino boards to play with now.

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Raspberry Pi Rack

Even before buying any Raspberry Pi computers, I had this sort of vision for neat rack to put several of them in. The idea evolved a bit as the logistics of it got ironed out but after picking up a second Pi (and planning to get a third), I went and built the thing.

Raspberry Pi Rack

Sorry for the mediocre pictures, I didn’t think to take photos until things were running and I didn’t really want to unplug it. It currently holds a Raspberry Pi B+ and a Raspberry Pi2 B, the B+ is running a ZNC server to keep me connected to several IRC channels and the Raspberry Pi 2B is running a small OpenSIM server, though I’ll probably re-purpose it since in testing performance seems to top out at around 2000 Prim cubes and 4 Avatars. The instance I’ve got running on my VPS is much more suitable. On the other hand, it could be a good place to “archive” builds.

Raspberry Pi Rack

The build itself is pretty straight forward. I used (roughly) the following materials picked up at Lowes:

  • 3 pieces of 10×8 plexiglass cut to 5×7 size.
  • 6 6″ #8 thread rods.
  • 8 (2 packages) of #8 rounded caps.
  • 3 packages of #8 nuts
  • 6″ Micro USB cables from Amazon
  • Cat 5 Cable cut and crimped as needed
  • 1 Netgear Switch I had already
  • 1 Choetech 40W Smart power from Amazon.
  • The smaller screws holding the Pis in are 4mm i believe, and it took two packages of them (16 screws and 32 nuts).

The hardest part was working with the Plexiglass pieces. I could have cut it with the Dremel but the edge would have been all crooked for sure. Instead I scored and snapped them, which did leave a jagged edge on one edge but it could easily be sanded off. On a starting note, the Plexiglass comes with a plastic protective layer, this should be left ON until final assembly to protect the clear surface as much as possible.

Anyway, to cut the sheets down, I used a square and a box cutter to but a line where I wanted the break to be on one side, then clamped the sheet down on the edge of the workbench between the surface and a 2×4. The 2×4 was mostly to help protect the surface of the plexiglass from the clamps. The cut edge should be on the up side, right at the edge of the surface and the 2×4 (or whatever) at the edge on top. The Plexiglass should snap more or less cleanly off. I had some small chips left hanging on the shorter 1″ breaks to shorten the shelves to 7″ from 8″. I used a small hammer while the pieces was still clamped down to chip these down a bit.

The real trick was drilling the holes. In the end, I found the best results came from clamping all of the plastic sheets together between some boards and drilling them all at once. There should be a piece of wood completely covering the bottom of the drilling spot to help support the plexiglass as the drill penetrates through.

I had some trial and error trying to drill my sheets separately, so the holes are not perfect. For the mounting holes I laid the Pi itself where I wanted it and uses a pen to mark the holes. I probably could have done a bit better with a paper guide though.

Assembly was pretty easy, just a lot of tedious screwing of nuts as the thread rods were fed through the holes. Each shelf takes at a minimum, one nut above and below to hold them in place and the rounded caps go on the top and bottom. The power supply and switch are not mounted, they are simply sandwiched in place between the shelves, though the supporting long bars were positioned around the Switch to prevent it from sliding left or right or backwards.

The Power supply I picked because it has two standard wall outlets on one side. I used the Dremel to cut holes in the top sheet to allow these plugs to be accessible. I wanted the unit to be as self contained as possible, these plugs give me a place to plug the Switch in. It’s important when choosing a power supply that it has enough power on all ports to power a Pi. A USB HUB doesn’t work since it will distribute power across all the ports. Several ports I looked at had 2 “high output” ports for iPads and iPhones but the rest were lower output.

The USB power cables were 6″ jumpers I found on Amazon and the CAT 5 cable were small jumpers I made myself with ends and a crimper. When I add the back two Pis I’ll need different cables though, likely cables with a 90 degree connector and definitely longer ones.

Raspberry Pi Rack

The whole package sits nicely on top of my desktop box next to my Synology NAS.