Footpad and "Bump Box" Adaptive Game Controllers // General Input Device

by william_doug in Circuits > Assistive Tech

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Footpad and "Bump Box" Adaptive Game Controllers // General Input Device

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Adaptive controllers I forged in the crucible of engineering class

These are two different game (and other stuff) controller ideas primary for individuals with poor motor control around the hands. I made two different components and used them in conjunction, providing eight separate inputs, (more if you get crafty). Although, both contraptions can function separately. They are a bit experimental, and I made them primarily to test how well they would work. My goal was to create a controller that would be simple to use, but not slow to use.

Feel free to deviate from the instructions, or skim through and just steal some ideas.

I've also attached the foot pedal cad below if you happen to have Fusion 360 you can modify it. (Student licenses are free and easy to obtain)


Demo Video (also attached above)



The first component I have dubbed the

Bump Box

[The hollow cube thing]

On the topic of the box: on the inner walls of the box there are two large conductive surfaces with a thin gap between them. When something touches both surfaces at the same time it completes the circuit and sends the input to the Makey Makey. On the walls I wanted to make a large button that didn't require force to press but also a button that wouldn't break easily if you did happen to press hard. My solution is a dead simple (but very large) button, with no moving parts. I will say there's probably a better style of button... but in this instance, it works well, and is considerably easier to make then an actual button.




Now, on to the other component

The footpad

My intention with the footpad was to have a pedal that could handle multiple inputs, and switch between them relatively easily and intuitively. There's definitely a bit of improvement to be done on the general layout, and it needs a bit more pressure than I expected to use. I designed the pad shaped like a left foot as I have difficulty rotating my right foot, however the pad is easily modifiable with cad to fit other feet. Also, I'd like to re do the pad in general to fit ether foot more securely.

The footpad is designed with two axis rotation, accomplished with a metal bearing and a 3d printed hinge joint. Despite the hinge being fully plastic it rotates surprisingly smoothly. At the end of the pad near the toes is a protrusion covered with conductive tape. (a material I've become intimately familiar with during the construction process as you will see). The protrusion comes into contact with the strips I put on the board in an arch formation, there lined up with the rotational range the footpad covered. Accomplished through eyeballing, not calculus.

The footpad uses a similar solution to buttons, by bridging the gaps between the conductive strips.




If by chance you want to make one of these contraptions, I encourage you to try to do it better than me. I hope the intention behind the designs are clear, and that they can aid in thinking up something better.

Supplies

Note: you may want to substitute some materials if you want to create a stronger version of one of the devices. This may require different tools.


Diagram

Bump Box Construction

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I began construction by cutting the base and walls out of a 3/4-inch foam core board. While the dimensions may be relative to your hand size, in my case I cut a 7x9 inch rectangle out from the base, then removed .75 inches of material lengthwise the base piece, however I left the bottom layer of the foam board attached. This is so the walls can be easily attached and look cleaner.

I removed the same amount of material from the walls but only on one side, this is to attach the roof of the box.

Cut Aluminum Sheets

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I flattened out and cut an aluminum rectangle that can cover a fair amount of the wall. I then sliced the sheet into two disproportionately sized sheets.

Attaching the Plates With Conductive Tape

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Conductive tape is useful because it can be used to make "traces" like a circuit board, as well as an adhesive that won't interfere with conductivity. I used it to attach two aluminum sheets each wall making sure there's a small gap between the pieces. The idea is to make as much as the wall conductive and place the gap in an area where your hand will come into contact with both plates whenever you touch the wall, completing the circuit and sending input to the Makey Makey.


I added an outline of conductive to each plate and cut holes to thread tape to the outside of the box to separate the wiring.

G L U E

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Add glue to edge of the base and place the wall flush the foam. If not using hot glue, use tape to secure the wall and set it against a vertical surface.

Wiring Conductive Plates

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With conductive tape I traced a path to the outside of the box through the holes I cut, this is so I can connect them and ensure the wires are out of the way.

At the end of the path, I wrapped a bit of extra tin foil around the tip for the alligator clips to attach to.

I also experimented with having a small copper wire protruding from the end, but this was inconsistent so I would be careful.

Making the Top Button

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For the top I wanted to use a more angular button and reduce the amount of upward movement needed to hit it, so I used a more complex button design. I removed a 2mm sliver about a 3/4 of the way a black piece of foam core viable in the image (1/8' core). I made sure to leave a paper layer connecting the piece with two sections, this creates a joint of sorts allowing the piece to bend. I glued the smaller section of the black rectangle to what would become the top of the box

I made the initial mistake of using hot glue to attach a rolled-up wad of tin, do not do this as the glue creates an electron sink, I remedied this by laying a piece of copper tape on top of the tin.

I would recommended just gluing a small rectangle of foam core and putting copper tape on that, to separate the glue and conductive material


Wiring Top Button

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Using the top of the box, add traces that lead to the front of the box.

Finishing Up the Top

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On the Topic of the Footpad

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The footpad relies heavily on a 3d print and bearing, if you do not own a printer yourself most library's now offer 3d printers for public use.



Footpad Assembly

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I tried to make the footpad brutally simple to make, and very much a blank canvas for improvement. I just wanted to see if the idea would work, which from my testing, seems to?

  1. I cut out a 4x4 inch square in the foam core making sure to leave the bottom layer intact
  2. I slotted the 3D print into the base (Assembly shown in video)
  3. I removed the cat (figure 2)
  4. I attached conductive tape to the protrusion on the pedal
  5. now that the pedal was in place, I put a pen against it and traced the path it drags along the foam core.



Adding Traces for Input

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using the path as reference, I added further conductive traces, to represent four different inputs.

This is the same general technique as the box.

Wire Them Up

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Using alligator clips you can connect both contraptions to the Makey Makey

I would recommend some longer traditional wire to extend the range of an alligator clip, as the footpad will need to be near your foot.

Success

In theory, at this point you should be done with both pieces, and they should be functional!