DIY Wireless DDR Dance Pad with Bluefruit EZ-Key

2020-05-27 | By Adafruit Industries

License: See Original Project

Courtesy of Adafruit

Guide by Paul Beaudet

Overview

What's DDR?

Dance Dance Revolution or DDR for short is a rhythm game that is played with a directional pad made for feet. Coordination and rhythm is tested by watching on screen dance notes making steps to the keys of the beat. It's a simple step on up down left or right and sometimes even combinations of steps. DDR has been very popular in arcades and on game consoles. Now-a-days, however, the game can be enjoyed with a clone games like "Beats" for android, "Stepmania" for the desktop, or even FFR (flash flash revolution) online. This tutorial generally explains how to go about building a wireless game pad on the cheap to avoid buy expensive adapters or pads. Bluetooth control with Bluefruit EZ-Key honestly works so easily for that there is very little to explain about the controller beyond what is covered in the Bluefruit tutorial. No programing required! As opposed to using a HID emulating micro like the Arduino Leonardo which would require some small bits of code and a wire.

Dance Pad

Materials

A number of different materials could be used in this project for the dance pad component. It’s all a tradeoff between reliability/quality, portability and cost. This tutorial prioritizes portability and cost. Using materials that might be found around the house or are affordable to get from the hardware store.

Cheapo method - As Shown

Sign board - plastic extrusion, large sheet at hardware store for under $10
Aluminum Foil - wrap leftovers, makes dance pads
Cat 3 cable - old telephone wire or whatever is available in 2'+ length
Packing foam - Trash that came in the "fragile" box years ago saved because it might be "handy"... well, now it is.
4 AA battery holder with switch

Quality approach- Recommended

Plexiglas - Or similar nice pad surface. Aesthetic
Sheet metal - Through hole and solder wires to sheets. Prevents disconnects with wear
Rubber pad - To reduce floor movement. Increases playability
? some sort of clicky type spacer ? in place of foam. Regular buttons are a bad idea because of the distribution of weight on the pad
LiPo battery and charge controller- In line solder/fasten a switch

Holding it all together

Duct tape, Foil tape (AKA actual metal duct tape not the plasticy gray stuff, although you need that too), hot glue, Velcro. More or less whatever it takes. In the following a lot of duct tape is use. There are likely more elegant ways to do it.

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Controller

It is possible to easily do this with the Arduino Leonardo or Micro and some simple code for a wired set up but using OTG with android can sometimes be a hit or miss affair and wires are cumbersome. For a similar price, just get a Bluefruit EZ-Key! No programing required and its wireless! Most Bluetooth projects and products are a nightmare. Bluefruit is a dream.

The Bluefruit EZ-Key HID is recommended as it makes this project super simple. For this project the headers were soldered on and the EZ-Key was placed on a breadboard stuck to a 4 AA power supply. One might also decide to power their project with a Lipo battery and Charge Controller combo. Follow the EZ-Key tutorial for a better understanding of its pins and power requirements. The simplified dance pad only requires the use of 6 pins. Vin, Ground, and 0-3.

Pin cheat sheet for DDR

0- UP
1- DOWN
2- LEFT
3- RIGHT

Bluefruit EZ-Key tutorial

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Tools and Prep

We'll start by making the dance pad itself, then add the Bluetooth part!

Tools

Utility knife and Scissors
Soldering iron
Hot glue gun -optional, contact spray might work better honestly
Wire strippers and snips
Conductance tester- Multimeter

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Design Note

A traditional dance pad has 10 buttons, but for the sake of simplicity and portability this design only incorporates the 4 most important buttons, UP, DOWN, LEFT, RIGHT. In Android with the "Beats" application which can be found in the Play Store, it is easy enough to touch the screen to select a song. Backing out of songs is for wusses, so that button can also be excluded. The other last 4 buttons are honestly redundant unless navigating through the console game menus.

Preparation

Cut the sign board into 8 (11"/ 28cm) squares. With sign board its useful to leave extra space and trim down to the cells. In a high-quality version, 4 rubber sheets and 4 Plexiglass sheets might be a good substitute.

Cut the foam into 16 small rectangles (about 1" x 2"), exact size depends on the type of foam used. Soft more, hard less, fairly soft foam is used in this pad. Hard or thick foam may make the pad difficult to use. Real pads use perforated sheets of thin (1/4") foam, this works well if thin foam sheets can be found. The redundant buttons on old pads provide good sheets. The directional key foam on store bought pads normally is the first thing to wear and lose resiliency. Making a faulty or unreliable pad. Another idea to separate the pad contacts might be short and wide springs given they are insulated from the contacts and fastened properly.

8 pieces of aluminum foil are needed to act as the pad contacts. About 70-90% of the square size is sufficient. In a higher quality version, it would be nice to use sheet metal. Drilling holes for the contact wires fishing them through and soldering in place. In this case contacts will be "secured" with foil tape. It works well enough, but for how long is another question.

cut_5

No really, cut away from yourself. It's a good idea.

Assembly

Step 1

Connect the power supply and test the Bluefruit to be sure it pairs.

Step 2

Prepare vinyl top. As shown in previous illustrations the redundant portions are cut from an old dance pad. This could be substituted with a plus shaped cut out of vinyl or other sheet material with similar qualities. Duct tape could make a sheet like this given some level of desperation. In this affordable case the vinyl also doubles as 4 hinges to the portable box conversion.

Step 3

If still untouched, solder the headers on the Bluefruit and bread board it on to the power supply. Alternatively solder needed wire directly. This project used less than 6' of CAT 3, which is a 4-strained solid core wire. Whatever is on hand will work. Cut into two 3' pieces gives 8 lines. 4 for ground and 4 for the pins. Needless to say, keep track on the wire colors. The 4 ground wires are common, they can be soldered into one wire at one end and connected to one of the grounds on the Bluefruit. Both of the wires can be fished through the sign board cells in the bottom "up" pad. This brings the wires to the middle of the four button pads.

Step 4

Glue sheets of aluminum foil to sign board squares. Be sure to center and abut the best edge of the foil to one side. This side will face the inside of the pad. Where connections will be made to the foil.

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Build Buttons

Step 5

Adhere the foam like in the picture, except slightly further apart. In hindsight the foam pieces in this up button were placed too close to the center making it more difficult to register a hot dance move.

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Step 6 or 7

Depending on which way seems easier. The top pad can be glued to the foam completing the sandwich or the wires can be foil taped to the pads. Given patience for the sandwiches to be made they were done first in this project, but doing the connections first is also valid, particularly for one with big fingers.

Two buttons

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Making connections

Foil tape will be used for this because of its conductive properties. Poke a pin hole in a half inch tear off, of tape after peeling. Push wire through this hole so that the bare wire gets stuck on the adhesive side and insulation is on the shiny side. Secure the insulation to the shiny side with another smaller piece of tape. Now stick that little electrode on the edge of one of the foil pads.

So long as all the pins go to a separate button this should come out right. It’s a simple circuit. Resistance is handled by a pull-up on the Bluefruit chip.

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