STM32 Motor + Heater + Audio Main Controller PCB — KiCad Schematic, PCB, Gerbers & BOM -- 2
Budget: ₹1,500 – ₹12,500 INR
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
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