Putting it All Together

Today's post is all about modularity. I have had a number of questions about how someone using the Styra Project designs will be able to customize their own keyboards. This post will hopefully demonstrate how different button layouts can be achieved with LEGO bricks and a little bit of imagination. All of the plates shown in this post were designed and printed by Phill Thomas.          

                       

Figure 1:  Top and bottom of button plate

The modularity of the Styra keyboards stems from the button plate design. Each button plate has a flat top and a reinforced button hole through which we can snap in an inexpensive joystick button. The bottom of the plate has a LEGO compatible interface around the edges so that it can connect with standard LEGO bricks.

Figure 2:  Assembled plate with button

Each button has a 12" cable terminated in a two pin header that can easily connect any of the custom Styra controller boards discussed in previous posts. The relatively long cable allows for a range of placement options without the need to perform any soldering. It is also possible to use extensions to move a button farther than 12" from the controller.

When working with LEGO bricks, the variety of sizes and shapes allows the creation of things limited only by one's imagination. I decided that this same philosophy would provide the greatest flexibility for the button layouts. After a bit of cajoling on my part, Phill consented to design a wide array of button plates. There is a downside to this approach; the spacing between the buttons cannot be any smaller than two lego units. This means that a keyboard layout for n buttons cannot be as compact as it could be if we custom designed a plate for each layout. The benefit is that layouts can be designed on the fly without modifying the 3D model and printing a new plate for each change.

 Figure 3:  Complete set of button plates

Figure 3 shows a complete "kit" of button plates. The contents of a kit were somewhat arbitrary; I worked through a few different layouts to figure out the quantity of each plate type. The following plates are included:

• 1x1 button plate - 8
• 1x2 button plate - 4
• 1x3 button plate - 4
• 1x4 button plate - 4
• 2x2 button plate - 2
• 2x3 button plate - 2
• 2x4 button plate - 2
• 3x3 button plate - 1
• 3x4 button plate - 1
• 4x4 button plate - 1

Phill had the 3D printer working day and night for a couple weeks printing two complete kits. These have proven extremely useful in our prototypes.

Talking about plates and layouts is one thing. Seeing them in action is another. The following images were taken while I was experimenting with a new button layout:

Figure 4:  Plates with buttons

The first step in designing a new layout is to use your imagination. Think about what might make a good button configuration. Play with the blank button plates to see what looks good and what doesn't. Once the design looks good, select the appropriate plates and snap the buttons in.  

Figure 5:  First layer of LEGO bricks

The first LEGO layer is critical. Sound LEGO engineering practices are recommended; mainly, try to make sure to provide as much connectivity between the plates as you can. Larger bricks (2x4) are really good for this for several reasons but the biggest is that the 3D printed plates don't always snap in tight with the blocks. This is par for the course, but larger blocks seem to stick better where smaller once may fall off.

The second layer is just as important. When applying the second layer of bricks, position them so that the seams between do not link up with the seams from the previous layer. In other words, span the seams.

Figure 6:  Third layer of LEGO bricks with blue accents and red cable paths

The third layer should be applied the same as the second, spanning the seams. With these shallow buttons, if the tabs on the back are bent over (gently), then it is possible to stop after three layers of bricks. It is tight and there is not a lot of room to route wires, but it is doable. For style, I like to add a splash of color to one of the layers. In this case I used blue bricks in the third layer. This layer is also where I routed the button cables and used red bricks as caps.

Figure 8:  Fourth layer of LEGO bricks

Finally, add a fourth layer in the same way as layers two and three. At this point the framework is strong enough to be entirely self-supporting. For my prototyping work I prefer to have a LEGO base to work with, so I built several base plates. They consist of 16x32 LEGO pads glued to inexpensive bamboo cutting boards. Figure 9 shows the completed button layout.

Figure 9:  Completed 16 button controller layout

Just connect a controller and assign macros to each button and this keyboard is ready for action!