ESP32 WiFi Fan Controller - Assembled Board

What is it?

A CE-certified ESP32-S2-based WiFi fan controller that gives you independent PWM control over up to 4 fans with built-in temperature and humidity sensing. Runs ESPHome firmware with native Home Assistant integration — auto-discovery, dashboard control, and automations out of the box.

Perfect for cooling server racks, network cabinets, 3D printer enclosures, grow tents, or any setup where you need smart, quiet fan control.

Key Features

• 4x Independent PWM Fan Control — each fan runs at its own speed, from full stop to 100%
• Built-in HDC1080 Sensor — temperature and humidity monitoring on the board
• RGB Status LEDs — per-fan color indicator (red = stopped, green = full RPM)
• ESPHome + Home Assistant — instant auto-discovery, OTA updates over WiFi
• Temperature Automation — PID, linear, or curve-based fan control runs locally on the device
• 0.25W Idle Power — always-on without the energy cost
• CE Certified — tested and compliant

Electrical & IO

• 12V DC Barrel Input (5.5x2.1mm, max. 2.5A)
• 4x 4-pin PWM Fan Headers with RPM sensing
• USB-C for firmware flashing and serial debug
• Qwiic I2C Expansion Port
• I2C Expansion Port (2.54mm Header)
• Neopixel RGB LED Port
• 3 User Buttons
• GPIO Expansion Pads (2.54mm SMD Header)

Use Cases

• Server Rack Cooling — mount 120mm fans (Noctua, Arctic P12) in your rack, automate based on temperature
• Network Cabinet — keep switches and routers cool without constant fan noise
• 3D Printer Enclosure — control chamber ventilation and filtration fans
• Grow Tent — automate intake and exhaust based on temperature and humidity

Software & Documentation

Ships pre-flashed with ESPHome factory firmware. Connect to WiFi via the captive portal, and Home Assistant discovers it automatically.

Full documentation, setup guides, and module reference: fancontroller.arthofer.dev

Open-source firmware and schematics on GitHub: github.com/zeroflow/wifi-fancontroller