Wireless Audio Control Interface (WACI) Jess Bardio, Louisa Beckwith, Joshua Berlin, Philip Del Signore, Matan Silver, Andrew Whitaker; Advisor: Prof. Bahram Shafai Hub Module System Overview • Seamless distributed system for small performing ensembles to wirelessly control audio effects and processing for multiple musicians • Leverages musicians’ existing audio processing software for simple learning curve • The Hub supports class-compliant multichannel audio input/output over USB • Users can send MIDI commands to any connected device • Cost and reliability advantages over using smartphones for wireless control • Cross-platform desktop application programmed in Electron enables pairing and configuration of Modules to the Hub • All circuit boards designed, populated, tested, and reworked by hand • Laser-cut enclosure for the Hub prevents mechanical strain on the circuit board • Custom circuit board manages communications between user’s computer and wireless modules • Implements circuitry for 6 input, 8 output audio interface • Support for 192kHz/24 bit sampling • Four inputs have microphone preamps; each can provide phantom power • Preamplifier circuitry introduces minimal noise to incoming signals • Over 600 electronic components per Hub • Custom firmware on XMOS microcontroller to implement Audio Class 2, CDC serial port and DFU firmware upgrade services • Communicates wirelessly with Modules using ESP32 wireless card • Requires no additional hardware besides a computer and wall plug • Schematic and layout in Altium Designer • Battery powered Modules send encoded MIDI commands to Hub over Wi-Fi • Fully wireless; can be freely moved around the stage within a 200-foot radius • Each Module can be outfitted with various UI components (knobs, buttons, foot switches, screens, etc.) to fit musician’s needs • OLED display shows status/configuration information • Low cost; each musician can use multiple Modules • Low-power design enables 24 hour battery life • Battery charging over USB-C • USB port allows Modules to act as an ad-hoc Hub