Prototype/Outcome

Our device uses the Arduino Nano 33 BLE Sense and an Adafruit 1.47" Round Rectangle TFT Display. We also utilized LED strips in the construction of the device.

The device works by pulling audio from the Microphone included on the BLE Sense board. The audio we are classifying is the sound from stirring the cup, which then is classified into a “Neutral,” “Slow,” and “Fast” stirring. These inform which images appear on the Display.

The images on the display were created in Photoshop. Since we knew the dimensions of the screen, we set a fixed canvas, downscaled reference images into it, recolored them as appropriate, and passed them into an online software called Ditherlicious. This software created dithered, 1-bit pixel art that could be passed into the TFT Display on a SIM card.

The device itself was designed in CAD, using precise measurements of the cup - which was purchased pre-made.

 

Using this 3D model, we cut the shapes from black acrylic, and assembled the final device. While it was challenging to hide all of the wiring and lights, the final result looked very polished. The only downside? Black acrylic tracks a lot of fingerprints.