Embedded Engineer for Voice-Controlled Hardware Retrofit — PCB Design + Firmware (Raspberry Pi +

I'm developing a retrofit control module that lets an industrial machine's parameters be adjusted by voice, without modifying the machine internally (it connects through the existing remote-control socket). Tech stack: Raspberry Pi 4 for offline voice processing, ESP32 for relay + digital potentiometer control (AD5293). Work needed: Custom PCB design (schematic + layout) Firmware for ESP32 (relay/potentiometer control) and integration with the Pi voice layer Offline wake-word + voice-command handling Structure: Project runs in two milestones — (1) materials/BOM + prototype, (2) development/labor. Requirements: Proven experience with Raspberry Pi + ESP32 embedded systems PCB design (please share past boards you've designed) Offline/edge voice processing experience is a big plus A short NDA will be signed before full specifications are shared. Please tell me briefly about similar hardware+firmware projects you've delivered.