Note: We expected to ship first orders of the duckJAWS SAO in the week of Nov 18

It all started with a small rubber duck that vividly fluoresced under black-light. Then I noticed, that the hole on the bottom, which usually holds a whistle, has the perfect size for a 5mm LED. LEDs are the main ingredient of SAOs, so this project was born and the rubber duckies multiplied.

duckJAWS is an SAO with a glowing rubber duck, lit up by an RGB LED, controllable over I2C. The PCB has the shape of a Jaws-style shark (sea-monster?) nibbling at the tail of the duck.

Electronics

The duck is lit up by a common anode RGB LED, as well as side-lit red LEDs to add an ominous glow to the shark's teeth.

The MCU on the SAO is a CH32V003, and its programming pin is exposed on GPIO1.

The SAO features a 3.3V boost converter. This ensures full LED brightness even when the SAO runs off unregulated batteries (like for example on the 2023 Supercon badge). 3.3V limits the brightness with a UV LED, so I might increase the voltage on a future revision.

Two solder jumpers allow to configure the SAO to four different I2C addresses.

Control

Out of the box, the RGB LED is set to yellow with its brightness pulsing very slowly.

Color and animation parameters can be controlled over I2C. When happy with the reconfigured rubber duck, the settings can be stored as new power-on default via another I2C command.

The documentation for the I2C registers is stored on the SAO and can be read over I2C. There's also an Easter-egg to reward the I2C curious.

In addition to I2C, the SAO also supports the WS2812 protocol on GPIO2, turning the rubber duck into a NeoPixel.

See GitHub for more detailed documentation of the I2C registers, including a few examples.

What's included

The SAO comes fully assembled and programmed. The duck is attached to the RGB LED with hot-glue. If the duck falls off, just add a dab of fresh hot-glue to reattach it.

If you'd like to build your own, you can find all design files and source code on GitHub.