This is a working resume of sorts. It’s a more fine-grained version of my professional accomplishments than the traditional one-page document. These are occasionally supplemented by blog posts, where appropriate, to illustrate what I’ve done, or what I learned from a project.
They go in reverse order, and trail what I’m working on now by about a year, out of respect for my current employer.
I’d be happy to chat about any of these topics in greater depth via Zoom, email, or in person!
- Conducted user interviews on report card comment software
- Built additional software features
- Pronoun scrubbing algorithms
- Comment template database at ReportCardComments.com
- Built email list and content marketing pipeline for teachers to improve ReportCardWriter’s search rankings
Root.ai -> AppHarvest
- Provided technical diligence on Root.ai’s electrical systems to the AppHarvest acquisition team
- Redesigned Virgo main system controller board after identifying numerous issues with its predecessor
- Responsible for all SCH design; supervised PCB layout with contractor
- Wrote all test firmware for board bringup
- Deployed board upgrade on in-house and field robots with field service team
- Continued to lead the Electrical and Embedded Systems team
- Grew the team from myself as solo contributor to four people
- Hired, managed, and developed individual contributors with a range of skillsets: firmware development, circuit design, cable design, and system integration
- Finalized development of Titan, the Sonos / IKEA collaboration that launched as the SYMFONISK Picture Frame.
- Worked as Rotational Product Manager with the Architectural Sound team.
- Conducted research on solutions for the architectural product space
- Held user interviews with custom integrators/installers on new product concepts
- Started a small, independent software company that helps teachers write report card comments more quickly. Check us out!
- Prototyped a first-run Python application/GUI for initial testing.
- Conducted dozens of user interviews to gather feedback on first prototype.
- Created landing page and marketing material to test broader response.
- Rewrote application with clearer user interface based on user feedback.
- Acquired a small, steadily growing user base through word of mouth.
- Joined Root.ai as a Principal Electrical Engineer.
- Architected the electrical system of the Virgo Mk.V and Mk.VI robots
- Identified and resolved issues around vibration-based sensing; redesigned to use more reliable optical beam-break sensors instead
- Managed the company’s transition from EAGLE to KiCAD
- Founded and led the Electrical and Embedded Systems (ESYS) team.
- Managed and planned team workload across releases.
- Launched Neptune publicly as the Sonos Port
- Worked with external power supply vendor on compliance and voltage sag issues
- Finalized design docs and test plans for manufacturing ramp
- Evaluation/bringup of the Amlogic A113L processor
- Schematic capture
- Subsystem design
- Directed and supervised layout
- Build out of detailed evaluation platform
- Bringup of boards
- Evaluation of the A113L voice activity detection peripheral
- Created model of VAD peripheral’s DSP pipeline in Python
- Verified performance of Python model against vendor’s Matlab DSP model.
- Integrated VAD model into Sonos Voice Quality test system; tested for regression against existing voice metrics.
- Started work on Titan project
- Modular CPU concept for easy reuse in multiple products
- Schematic capture, testplan development, specifications work to ensure proper operation
- Redesigned amp circuitry to improve click/pop
- Debugged power routing to eliminate wifi noise coupling into amps
- Completed bringup and system integration of the MT7613 wifi radio into the Titan board
- Served as scribe for Innovation Discovery Event tech transfer sessions at:
- Princeton Plasma Physics Laboratory; Princeton, NJ
- US Department of Agriculture; Beltsville, MD
- Digital Lead for Sonos Amp (Codename: Hideout)
- Shipped early and under budget - Sonos first!
- Root caused several breaking issues around memory, compliance, auth circuitry
- Owner of digital protection circuitry in amp - implemented subsystem communications and protection circuitry using dsPIC MCU
- HDMI Compliance Issues
- Discovered breaking compliance issues for multiple products implementing Mediatek MT8521P processor
- Prevented serious compliance problem in product shipments - fixed with SW update after diagnosis
- Lead EE for Neptune project (later shipped as Sonos Port)
- Owner of all electrical assemblies
- Responsible for schematic, PCB, testplan development
- Designed and spec’d low-noise D/A chain with -109dB THD+N (>20dB THD+N/SNR improvement over prior system)
- Designed and spec’d 12V trigger circuitry
- Digital Lead of Paramount project - CPU/Radio Redesign of Sonos Connect
- Diagnosed and resolved radiated emissions issues in Ethernet chain
- Resolved audio click/pop issues - traced to poorly documented legacy hardware
- Shipped on time for $13.50 savings per unit, ~$3.4million annual savings
- Implemented PDM microphone demodualtor/DSP pipeline in Verilog
- Implemented CIC filtering and polyphase lowpass FIR filter to convert PDM mic output to I2S
- Integrated PDM decimation filter in Lattice ICE40 FPGA
- Digital Lead - Hideout - ConnectAmp Refresh
- Owner of PCB assembly for CPU/RF circuitry
- Owner of digital protection circuitry in amp
- Designed/architected dsPIC33 MCU as mixed/signal amp controller
- Responsible for all abstraction of amp subsystem
- Implemented subsystem communications and DSP protection functions
- Co-designed custom class D amplifier featuring novel modulator technology from Qualcomm
- Started work on the Paramount project - redesigned Sonos Connect for lower cost
- Owned architectural decisions, board bringup, prototype testing, thermal budgeting
- Developed crossfunctional sepcs for test fixturing, diagnostic SW development, and system integration
- Prototyped first Sonos board with HDMI as feature
- Prototype board featuring the NXP iMX6DualLite
- Did initial bringup of Mediatek MT7615 radio
- Completed firmware bringup of wireless power transfer prototype
- Initial bringup of system microcontroller
- Developed proof-of-life firmware for diagnostic shakeout
- Managed the early life failure program for the Sonos Boost; identified and resolved issues not discovered in production ramp
- Redesigned CPU clock network of Sonos ConnectAmp CPU as part of a memory upgrade
- Developed continuous qualification program for streamlining component second sourcing
- Debugged line-halting amplifier overcurrent issue in Sonos Playbar
- Established second source qualification procedure for DRAM and NAND Flash memories
- Discovered widespread bug in Spansion NAND Flash chips; received a very nice thank you note from the CEO of Spansion
- Data-mined manufacturing logs for analytic trends on failed DRAM modules
- Developed DRAM performance monitoring software for Intel Sandy Bridge series processors
- Resolved line-down issues regarding Flash and DRAM memory supply
- Standardized NAND Flash qualification procedures