STM32 Motor + Heater + Audio Main Controller PCB — KiCad Schematic, PCB, Gerbers & BOM

I need an experienced embedded hardware / PCB engineer to design a production-ready STM32-based main controller PCB for a therapeutic massage/spine bed system. This is a build-to-spec project. I already have a detailed engineering handoff package including system architecture, old PCB references, estimated current budget, pin maps, connector notes, BOM guidance, firmware handoff notes, layout requirements, and test plans. The freelancer’s main responsibility is hardware design and manufacturing outputs: schematic, PCB layout, Gerbers, BOM, assembly files, and firmware-ready hardware documentation. Firmware will be developed separately using AI/Codex/Claude from existing working ESP32 firmware. I will burn the firmware once the board is ready. The PCB must support first firmware flashing, debugging, recovery, and future OTA updates. Target Board Onboard STM32G474RET6 LQFP64 main MCU ESP32-C3 WiFi/BLE command bridge 24 V system input Main motor control Lift actuator / second motor control 4 heater zone control channels Independent hardware thermal cutoff per heater zone Jade roller PCB UART/control/power interface 433 MHz RF receiver support Bluetooth Classic/A2DP audio module TPA3116D2-class Class-D amplifier Wired 8 ohm / 15–20 W mono speaker output Optional microSD footprint, DNP allowed SWD debug/programming access ESP32 programming access OTA-ready hardware support through ESP32-C3 Factory test points and diagnostics Firmware / OTA Clarification The first firmware will be flashed using SWD/programmer or wired service access. Future updates should be possible through an OTA update path using ESP32-C3. OTA must not be the only recovery method. The PCB must include: STM32 SWD header BOOT0/NRST recovery access ESP32-C3 programming access safe reset/boot circuit all motors/heaters default OFF at reset/power-up hardware support to recover if OTA fails Scope of Work Design a complete KiCad project including: multi-sheet schematic 4-layer PCB layout STM32G474RET6 MCU circuit ESP32-C3 bridge circuit power input protection: fuse/eFuse, TVS, reverse-polarity protection buck regulators for logic rails main motor driver / smart H-bridge stage lift actuator driver stage 4 heater switching circuits independent thermal cutoff per heater zone limit switch / hall / fault input circuits Jade PCB UART/control/power interface RF receiver circuit Bluetooth audio module circuit Class-D amplifier and speaker connector optional microSD footprint SWD/debug/programming connectors test points for power, UART, PWM, faults, current sense, reset, boot connector/harness map Safety-Critical Requirements Motors and heaters must default OFF at reset and power-up. Heater safety must not rely only on firmware. Each heater zone must include independent in-line thermal cutoff. Limit switches and fault signals must be visible to STM32. Board must support safe firmware recovery if OTA update fails. Old Gerber files provided are reference only and must not be reused as final output. Deliverables Freelancer must provide: KiCad schematic source KiCad PCB source schematic PDF ERC report DRC report Gerber files NC drill files pick-and-place / CPL files assembly drawing final BOM with exact MPNs, ratings, footprints, quantities, and purchase links Gerber viewer screenshots connector/harness map final STM32 pin map CubeMX .ioc board_config.h style pin definition file boot/reset/programming notes OTA/recovery hardware notes bring-up checklist Required Experience Please apply only if you have experience with: KiCad v7/v8 STM32 schematic and PCB design STM32G4 or similar MCU ESP32 module integration SWD/debug/bootloader hardware design OTA-capable embedded products 24 V motor control H-bridge or smart motor driver design heater control and thermal safety MOSFET/current/thermal design eFuse/fuse/TVS/reverse-polarity protection 4-layer PCB layout mixed-signal grounding Class-D audio layout DFM/DFT and manufacturing file generation

Project ID: 40563560