A good calculator is indispensable, but there’s a strong chance you’re still using your TI-83 from high school. If you want to upgrade to something with more features, the options currently on the market are actually pretty limited. Luckily, you can build Andrea Cavalli’s DIY WarpPi calculator and set it up to fit your specific needs.
Cavalli’s design has a Raspberry Pi Zero W at its heart, and the calculator functions were programmed in Java. Unlike most calculators, Cavalli’s CAS (Computer Algebra System) provides step-by-step solutions to a problem. The hardware itself is also really impressive, and utilizes a custom-designed scientific calculator keypad PCB. That, along with the 3D-printed case and the code to run it, are all available on the WarpPi GitHub page, so you can build one yourself.
Even better, it can do more than just math. Because everything is running on a Raspberry Pi, you can install and use whatever other software you want. For instance, Cavalli shows it being used to run an NES emulator to play Super Mario Bros. If you want to try the calculator software for yourself, Cavalli has uploaded a live web preview so you can see it in action.