An enclosure for rapid prototyping with the Arduino Uno.
Connect the top using LEGO technic pins, M3 bolts or nylon wire ties to allow easy field configuration and attaching other parts such as sensors.
To optimize LEGO-compatible features for printing with other materials, download the parametric model from https://pelablocks.org and open with the OpenSCAD customizer
The OpenSCAD model is too complex for the online customizer. This model is free, open source and available at https://pelablocks.org Download there and you can drag sliders to adjust the model for a better fit with LEGO-technic pins on your printer and preferred material.