Design a Compact Universal ESP32 Smart Fan-Regulator PCB with Wi-Fi, Ethernet, BLE, Gerbers and 3D Enclosure

About the project

Project Title Design a Compact Universal ESP32 Smart Fan-Regulator PCB with Wi-Fi, Ethernet, BLE, Gerbers and 3D Enclosure Project Description I need an experienced embedded-hardware and PCB designer to develop a compact smart controller for traditional capacitor-type ceiling-fan regulators. The controller must work with both 4-speed and 5-speed mechanical rotary fan regulators while retaining: * The original regulator knob. * The original rotary switch. * The original capacitor-bank PCB. * The original speed characteristics of the regulator. The rotary switch will be desoldered from the capacitor-bank PCB. It will then be used only as a low-voltage input to the ESP32. The smart controller’s isolated relay outputs will reconnect to the original rotary-switch pads on the capacitor-bank PCB and reproduce the same electrical connections. For a 4-speed regulator, the fifth input and fifth output will remain unused. No custom capacitor bank is required. ⸻ Required Architecture Rotary-knob input The controller must provide six low-voltage input connections: Common Speed 1 Speed 2 Speed 3 Speed 4 Speed 5 The original rotary-switch terminals will connect directly to these low-voltage inputs. The original rotary switch must no longer carry 230 V. Capacitor-bank output The controller must provide six isolated dry-contact output connections: Common Speed 1 Speed 2 Speed 3 Speed 4 Speed 5 These outputs will connect to the original rotary-switch pads on the existing capacitor-bank PCB. Only one speed output may be active at a time. The input and output order should be configurable so the controller can work with different traditional 4-speed and 5-speed regulator brands. ⸻ Main Hardware Requirements * ESP32-based controller. * Wi-Fi capability. * Bluetooth Low Energy capability. * Wired Ethernet using W5500 or another proven Ethernet controller. * Five low-voltage rotary-switch inputs. * Five isolated, mains-rated relay outputs. * Isolated 100–240 VAC to low-voltage power supply. * Mains fuse and surge protection. * Safe creepage and clearance between mains and low-voltage sections. * Hardware pull-downs so all relays remain OFF during boot, reset and programming. * Break-before-make relay switching. * No possibility of two speed outputs operating simultaneously. * Compact Sonoff-MINI-style enclosure. * Programming and diagnostic test pads. * Suitable for conventional non-BLDC ceiling fans. Preferred approximate enclosure target: 70 × 45 × 25 mm A slightly larger size is acceptable if required for safe isolation, relay spacing or Ethernet. A stacked two-PCB design may be used if it produces a safer and more compact product. ⸻ Four-Speed and Five-Speed Support The same controller PCB must support both regulator types. Four-speed mode Inputs 1–4 used Outputs 1–4 used Input 5 and Output 5 unused Five-speed mode Inputs 1–5 used Outputs 1–5 used The mode should be selectable through firmware configuration, jumpers, solder bridges or another simple method. No physical regulator samples or photographs will be supplied. The controller should therefore use a universal input/output arrangement, with clear instructions for mapping the rotary-switch terminals using a multimeter. ⸻ Home Assistant and Firmware Compatibility The final application firmware will be developed separately by the client using ESPHome. The freelancer does not need to develop the complete Home Assistant automation or final fan-control firmware. The PCB must be fully compatible with ESPHome and must provide sufficient documented GPIOs for: * Five rotary-switch inputs. * Five relay outputs. * W5500 Ethernet. * Wi-Fi. * BLE. * Status LED. * Programming and reset functions. The freelancer must provide: * Complete GPIO allocation. * Relay polarity. * Ethernet SPI pin allocation. * Input logic and pull-up/pull-down arrangement. * Boot-strapping pin review. * Confirmation that relays remain OFF during boot and firmware flashing. * A basic factory-test firmware or test program. The test firmware should allow verification of: * Each rotary input. * Each relay output. * Wi-Fi. * Bluetooth. * Ethernet. * Power-supply stability during relay switching. No RainMaker, Blynk, Tuya or proprietary cloud dependency is required. ⸻ Required Connectors The design should use keyed, locking connectors. AC input Line Neutral Rotary-knob input Common Speed 1 Speed 2 Speed 3 Speed 4 Speed 5 Capacitor-bank output Common Speed 1 Speed 2 Speed 3 Speed 4 Speed 5 The low-voltage knob connector and mains-side capacitor-bank connector must be physically different and impossible to interchange accidentally. The freelancer must specify: * Connector manufacturer and part numbers. * Matching housings. * Crimp terminals. * Recommended wire size. * Pin numbering. * Wiring diagrams. ⸻ PCB Deliverables The completed design must be ready for ordering from JLCPCB. Required files: * Editable KiCad project. * Complete schematic. * Complete PCB layout. * Gerber files. * Drill files. * JLCPCB-ready BOM. * LCSC part numbers wherever available. * Pick-and-place/CPL files. * Assembly drawings. * Custom symbols and footprints. * PCB design-rule settings. * Populated PCB STEP model. * PDF schematic. * Connector pinout sheet. * Wiring diagram. * Test-point documentation. The designer should maximise JLCPCB assembly and clearly identify any parts that must be fitted manually. All component rotations and footprints must be checked against JLCPCB assembly requirements. ⸻ 3D Enclosure Deliverables A compact enclosure must be designed for 3D printing through Robu or another 3D-printing service. Required files: * Editable CAD file. * STEP file. * STL file for enclosure top. * STL file for enclosure bottom. * Complete assembled STEP model. * Dimensioned mechanical drawing. * PCB mounting details. * Screw and heat-set insert specifications. * Recommended print orientation. * Recommended material and tolerances. The enclosure should include: * Protected AC input. * Ethernet opening or Ethernet-pigtail opening. * Knob-input cable opening. * Capacitor-bank output opening. * Internal separation between mains and low-voltage wiring. * Cable strain relief. * PCB mounting bosses. * No exposed mains terminals. * Clear connector labels. ⸻ Safety and Switching Requirements The design must include both hardware and firmware provisions to ensure: 1. All relay outputs remain OFF during power-up. 2. All outputs open before changing speed. 3. A short delay occurs before the new speed output closes. 4. Only one output can be active at any time. 5. Invalid rotary-switch combinations are ignored. 6. Relay switching does not reset the ESP32 or Ethernet controller. 7. Mains and low-voltage sections have suitable isolation. 8. The product can safely control a conventional ceiling fan through the existing capacitor-bank PCB. The designer must review relay suitability for capacitor switching and conventional ceiling-fan loads. ⸻ Documentation Required The final package must include: * Installation instructions. * Procedure for desoldering and rewiring the original rotary switch. * Procedure for identifying rotary common and speed terminals. * Procedure for identifying capacitor-bank common and speed pads. * Four-speed wiring example. * Five-speed wiring example. * First power-up procedure. * Hardware test procedure. * Programming procedure. * Troubleshooting guide. * Safety notes. * Production test checklist. ⸻ Prototype Support The quotation should include support during the first prototype build and testing. At least one reasonable revision should be included for: * PCB corrections. * Component changes. * Enclosure-fit corrections. * Connector changes. * Hardware issues found during prototype testing. The final revised Gerbers, BOM, CPL and enclosure files must be provided after prototype feedback. ⸻ Final Handover The following must be transferred at project completion: Editable KiCad files Gerbers and drill files JLCPCB BOM and CPL LCSC part numbers Editable libraries PCB STEP model Basic hardware-test firmware GPIO allocation table Connector and harness documentation Editable enclosure CAD STEP and STL enclosure files Installation and testing documents Manufacturing rights No locked files, encrypted firmware or vendor-controlled account should be required. All design and manufacturing rights must be transferred to the client after final payment. ⸻ Freelancer Experience Required Please apply only if you have experience with several of the following: * ESP32 product design. * Mains-powered smart switches. * Relay control of capacitor-type fan regulators. * W5500 Ethernet design. * Safe mains PCB layout. * JLCPCB assembly files. * Compact IoT product design. * 3D-printable electrical enclosures. * Home Assistant or ESPHome-compatible hardware. Experience designing commercially sold smart switches, fan controllers or 3+1 node products is preferred. ⸻ Please Include in Your Proposal 1. Examples of similar mains-powered PCB products. 2. Examples of ESP32 and Ethernet designs. 3. Proposed ESP32 module. 4. Proposed relay model. 5. Proposed isolated power supply. 6. Expected PCB and enclosure dimensions. 7. Confirmation that the board will support both 4-speed and 5-speed regulators. 8. Confirmation that JLCPCB-ready manufacturing files will be supplied. 9. Confirmation that editable PCB and enclosure files will be supplied. 10. Number of prototype revisions included. 11. Estimated completion time. 12. Fixed-price quotation. Generic proposals without relevant PCB examples will not be considered. Preferred Contract Fixed-price contract with milestone payments. Suggested milestones: 1. Architecture, component selection and schematic. 2. PCB layout and mechanical design. 3. JLCPCB and 3D-printing production files. 4. Prototype support and final revision.

Skills required