w32-ControlHub

The w32-controlHub was a key component of the littleBits Droid Inventor Kit. It acts as the brain of the build-it-yourself robot, allowing several functions of the droid to be controlled over Bluetooth Low Energy (BLE). The controlHub communicates with a mobile application and allows a user to read from inputs, write to outputs, play back sound effects, and run rudimentary user programs. The Droid Inventor Kit included many other parts from the littleBits platform as well as a custom plastic assembly enabling users to assemble their own Droid.

The design was built around a Nordic nRF51-series BLE Radio SoC (used for communication) and a Silicon Labs EFM8 8051 MCU (for sound playback and I/O). Audio files were stored on a small SPI NOR flash chip, played back in a Class-D fashion through a small amplifier and speaker. Low-lanecy operations like SFX playback and output PWM were implemented on the 8051 coprocessor. A custom storage format was written for the flash chip, and a communication protocol for control and configuration.

I was a part of the team that was invited to participate in the 2016 Disney Accelerator Program. We pitched a variety of concepts to executives within the Disney corporation, leading to a partnership that produced the Droid Inventor Kit. I helped the team to develop the kit concept, designed the w32-controlHub bit, assisted the software team with device communications, edited the audio for the project, and was boots-on-the-ground during our very ambitious ramp up at a CM in southern China.