Freelance Embedded Systems / Firmware Engineer — Consumer Wellness Hardware

Miami or Savannah preferred (remote considered) · Contract, project-based · NDA required Early-stage wellness hardware company (Wyoming LLC, founder-led, self-funded) building a compact, standalone consumer device. No hardware exists yet — you'd be the first technical person on the project. Phase 1: prove the core mechanism on a breadboard. Custom firmware for precisely timed, multi-level control of an output element, running in sync with audio playback from internal flash to a 3.5mm output. Timing precision is the whole product. Later: schematic + PCB for a ~9×5×3 cm form factor, USB-C charging and Li-Po management, content transfer over USB-C, BOM and ODM handoff. You have: Embedded C/C++ on ARM Cortex-M or similar (STM32, nRF52, ESP32) Real-time, timing-critical control loop experience Embedded audio: I²S, DAC, codec, playback from flash Battery-powered consumer product experience Schematic capture / PCB layout a strong plus Phase 1 is scoped small on purpose — a paid trial for both of us. Long roadmap ahead for the right person. Send 2–3 examples of embedded products you've built, your usual MCU families, availability and rate