Modular STM32 Smart Power Controller

I’m building a next-generation smart-home power controller and need the complete electronics and firmware design. The unit must be modular yet robust, offering six independent electromechanical relays that each carry up to 15 A. An STM32WB55 series MCU will handle all application logic and run a full Zigbee 3.0 mesh stack, so the PCB has to respect RF layout best practices and give me a dependable antenna feed.

Each relay requires its own ACS724 current-sense channel and a zero-cross detection circuit to minimise stress on the contacts. I also want an SHT4x sensor on board for ambient temperature and humidity, an RGB status LED for global health, and individual LEDs that mirror the state of every relay.

Industrial-grade reliability is non-negotiable. Please factor in proper isolation, track clearances, surge protection, and any other safety measures that let the board live inside a switchboard without babysitting.

Deliverables
• Schematic and multilayer PCB layout (Gerber + pick-and-place)
• Verified RF section suitable for the STM32WB55’s 2.4 GHz radio
• BOM with qualified parts for 15 A switching
• Firmware source (STM32CubeIDE / C) that demonstrates:
– Secure Zigbee 3.0 joining
– Individual relay control with zero-cross timing
– Real-time current, temperature, and humidity reporting
– RGB status feedback
• Brief test report showing all six channels switching 15 A resistive load without issue

To help me choose quickly, attach past work that proves you can deliver RF-aware, high-current, safety-compliant designs. A concise portfolio link or couple of photos with a short description is all I need at this stage.