KiCad Redesign for ESP32 Fan Hub

Design the GreenBreeze Hub PCB in KiCad, and a wiring drawing for the GreenBreeze Mini Multiplexer. The full specification is the attached PDF, GreenBreeze_Design_Requirements.pdf. That PDF is the requirement. This posting is only the summary. The Hub drives Strikefan TRD1238B24M fans (24 V, 0.94 A max, 4-wire). Each floor has 1 to 5 fans. There are up to eight floors. The Hub does not carry fan current. It only produces PWM. Start from the supplied Illuminator Hub KiCad project and keep its body: - Same PCB outline, 4-layer 1.6 mm stack-up, and four M3 mounting holes. The board must fit the Altinkaya SF-226 enclosure. - Same ESP32-WROOM-32E-H4, W5500 Ethernet, RJ45, USB-C / USB-UART, boot and reset, and the 24 V logic input. - Remove the 0–10 V path (DAC7678, OPA4197, RJ25 6P6C jacks). Replace it with eight independent PWM outputs: - Fixed 25 kHz. Duty 0–100% in steps of 1% or finer. 0% stops the fan. 100% is the 4600 rpm region. - 5 V push-pull buffer. An ESP32 GPIO must not drive the jack. The 5 V rail is a switcher from 24 V, not an LDO. - Connector is 4P4C. Latch down, contacts facing you, left to right: pin 1 PWM GND, pin 2 PWM, pin 3 PWM, pin 4 PWM GND. Two twisted pairs, each pair one PWM and one PWM GND. - Choose the PWM parts for heat inside the closed SF-226 at 24 °C room temperature. Eight channels running: rise within 10 °C. One output shorted to GND: the other seven keep running. All eight shorted: no permanent damage, and the 3.3 V rail stays up. - If Ethernet drops or the application stalls, the last duty is held in hardware and restored from non-volatile memory after reboot. Unused ports stay low. This is not required when Hub power itself is removed. The Mini Multiplexer is not a PCB. It is an Altinkaya SF-207 box with four WAGO connectors: - +24 V and GND: one WAGO 221-613 each (3-pole, 6 mm²). Chain current can reach 37.6 A. - PWM and PWM GND: one WAGO 221-415 each (5-pole). - Fan cable: red +24 V, black GND, blue PWM, yellow FG left open. A factory 10 kΩ holds PWM low when the Hub cable is unplugged. - One drawing shows which wire enters which pole, for both per-port and daisy-chain wiring. No mode switch. No firmware in the box. You deliver: 1. KiCad schematic and PCB derived from the Illuminator Hub files. 2. ESP32 GPIO table for the eight PWM channels. 3. 4P4C jack part number. The pin map above does not change. 4. Thermal calculation for the PWM buffers and the 5 V regulator, including one port driving 40 fan inputs and 6 m of cable. 5. A short note that HIGH stays at 3.3–5.5 V and LOW stays below 0.5 V at the fan after that cable. 6. Gerber, drill, BOM with LCSC part numbers, and pick-and-place. 7. A check that the assembled Hub fits the SF-226. 8. The multiplexer connector-placement and wire-list drawing. No multiplexer PCB. Out of scope: firmware, enclosure machining, glands, the Y connector, the fans, and the 24 V power supply. Please bid a fixed price. In your proposal, name two boards you have taken from schematic to Gerber in KiCad, and say whether any of them included ESP32 and Ethernet. The KiCad reference project and enclosure drawings are shared with the selected designer.