You’ve made yourself a great project for your Circuit Playground Express, now all you need is a box to put it in. How do you keep your Circuit Playground safe in a housing while still being able to press the buttons and use the sensors? Design your own box! 3D Printing offers an unlimited number of options for housing your Circuit Playground.
In this tutorial we will show you how to make a pretty practical 3D printed box for your Circuit Playground Express and mount a switch and a potentiometer to the top of the box. We offer a 3D Printing Service that we added to make 3D printing more accessible to anyone!
Pick your Software
There are many different options out there for designing in 3D. They generally fall into two categories, dimension driven designing and free-form modelling. Out of all the options we've tried out, we recommend using Fusion360 by Autodesk. Its free to use, cloud-based and very powerful. You can do both dimension-driven designing or free-form modelling too!
When you have completed your design you will need to export it as a .stl file to your 3D printing software (Our Printers use Cura LulzBot Edition). Whatever design software you choose, as long as it can export a .stl it will work. Some other free design software you could use:
- Sketchup – good for beginners, but doesn't have native STL exporting
- Blender – most suitable for free-form design, but isn't the most straightforward or easy to use piece of software we've used
You will need also need a Slicer program (like Cura) to print your design. If you are sending your .stl to a service to be printed then this isn’t necessary. This tutorial is focused on design rather than the specifics of 3D printing. If you want to learn more about 3D printing, check out our 3D Printing Tutorials, or our 3D Printing Online Workshop! Oh, and if you don't have a printer, we now offer a 3D printing service and will print your design and ship it out to you!
Design the Box
You don’t need to make your housing complex for it to be effective. I’ve chosen to make a simple box with a lid that fits inside the base. Keep in mind when designing your box that the filament turns out slightly bigger than the design. So if you need the lid to fit inside the base design the lid to be slightly smaller. 0.25mm on each edge should be enough to keep a snug fit. We decided to mount the Circuit Playground on standoffs and have it sit slightly below an opening in the lid. This allows access to the sensors and buttons on the board while saving plenty of space below the Circuit Playground for the battery.
When making the standoffs to support the Circuit Playground Express, you need to make holes in the standoff for bolts to thread into. You should make the holes 0.5mm diameter larger than the bolt. This will provide a tight enough fit for the bolts to thread in. The holes in the Circuit Playground are just over 3mm, so a 3.5mm hole is as large as you should get.
Once you’re happy with your model export it as a .stl file and use a slicing program like Cura to Slice and print it! If you would like us to 3D print your model for you, head over to our Services section for 3D printing. All we need to print is the .stl file.
If you want to try printing our box you can Download the box from Fusion360!
Wire It Up!
We are going to take advantage of all this extra space in the Circuit Playground box we’ve added a toggle switch and a potentiometer. The potentiometer uses a power and ground from the Circuit Playground Express, and the analog voltage is read off the centre pin. I've used alligator clips to keep the components reusable and made the box big enough to accommodate the clips.
We’ve created a sketch in MakeCode that uses the switch and potentiometer we connected to the Circuit Playground Express to control the speed and direction of the light “Photon” animation. The potentiometer value is read from pin A5 and mapped to a value between 0 and 255. This controls the hue of the lights and changes the delay between each light movement. We set pin A1 to digital High, and A2 detects when the switch is flipped. The state is then changed to reverse the direction of the photon.
A good idea would be to wire up the toggle switch to the battery so you can easily turn the power on and off to your Circuit Playground Express without having to take the lid off the box. If you want to learn more about 3D printing you can check out our 3D Printing Tutorials, or our 3D Printing Workshop! We have many more Circuit Playground Express Tutorials, and an online Circuit Playground Workshop that takes you all the way from Circuit Playground Zero to Hero! If you are looking for more designs for the Circuit Playground Express, for Fusion360 you can download some drawings for a round, and a square case.