Sand Physics Toy

Build a beautiful 3D printed hourglass physics toy using LED matrices and an Adafruit Feather Sense. Use CircuitPython to simulate particle collision code on a small microcontroller packed with tons of sensors. With built-in lipo charging over USB, your projects can be small and portable!

Sand Toy Upgrade

This is an add-on to Carter Nelson's Time Triangle Thing learn guide. It uses a similar circuit and slight code adjust to make a portable hourglass in a 3D printed case.

This uses the Feather Sense on-board accelerometer to simulate an hourglass with interactive grains of sand. This looks and feels like it’s actually been affected by gravity.

3D Printed Case

The hourglass is made up 3D printed parts that snap fit together. The electronics are housed in the base. The assembly is modular and easy to put together. Parts are 3D printed without any support material.

Project Inspiration

This was inspired by @david_proyectos See his LED hourglass build posted on instagram

Prerequisite Guides

Take a moment to walk through the following learn guides.


Mini and Small

The LED Matrices are available in 1.2in and 0.8in sized displays. The case was designed for both sizes and feature similar circuits and assembly. The LEDs come in various colors, so there are a few options to choose from.

1 x Silk Gold PLA
2.85mm diameter filament on Amazon
1 x Silk Gold PLA
1.75mm diameter filament on Amazon
Angled shot of blue, rectangular, microcontroller.
The Adafruit Feather Bluefruit Sense takes our popular Feather nRF52840 Express and adds a smorgasbord of sensors...
Adafruit Mini 8x8 LED matrix w/I2C Backpack- Yellow.
What's better than a single LED? Lots of LEDs! A fun way to make a small display is to use an 8x8 matrix or a
Adafruit Small 1.2" 8x8 Yellow LED Matrix w/I2C Backpack assembled and powered on. A yellow graphic smiley is displayed.
What's better than a single LED? Lots of LEDs! A fun way to make a small display is to use an 8x8 matrix or a
Slim Lithium Ion Polymer Battery 3.7v 400mAh with JST 2-PH connector and short cable
Lithium-ion polymer (also known as 'lipo' or 'lipoly') batteries are thin, light, and powerful. The output ranges from 4.2V when completely charged to 3.7V. This...
Breadboard-friendly SPDT Slide Switch
These nice switches are perfect for use with breadboard and perfboard projects. They have 0.1" spacing and snap in nicely into a solderless breadboard. They're easy to switch...
Angled shot of JST SH 4-pin Cable with Premium Female Sockets.
This 4-wire cable is a little over 150mm / 6" long and fitted with JST-SH female 4-pin connectors on one end and premium female headers on the other. Compared with the chunkier...
Angled shot of ten 4-pin JST-SH connectors.
If you're a DIY enthusiast who likes to micro-manage your project's connections, here is a 10-pack of some micro JST SH...
10 wire Silicone Cover Stranded-Core Ribbon Cable
For those who are fans of our silicone-covered wires, but are always looking to up their wiring game. We now have Silicone Cover Ribbon cables! These may look...
USB cable - USB A to Micro-B - 3 foot long
This here is your standard A to micro-B USB cable, for USB 1.1 or 2.0. Perfect for connecting a PC to your Metro, Feather, Raspberry Pi or other dev-board or...

This guide was first published on Jul 07, 2020. It was last updated on Jun 17, 2024.

This page (Overview) was last updated on Mar 08, 2024.

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