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