First Setup

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Your board ships with factory firmware already flashed. This guide walks you from unboxing to a working fan controller in Home Assistant, covering WiFi provisioning, fan wiring, and Home Assistant adoption.

Already flashed from the factory

Every WiFi Fan Controller is flashed with factory firmware before shipping. First-time users can skip straight to WiFi provisioning below. If you ever need to re-flash (corruption, recovery, or a custom ESPHome build), the “Re-flash firmware” section at the bottom of this page covers it.

What You’ll Need

• WiFi Fan Controller board
• USB-C data cable (not charge-only), used for serial-based WiFi provisioning
• 12V DC power supply (5.5x2.1mm barrel jack)
• One or more PWM fans (4-pin)

Setup Steps

1. Connect to WiFi

   Connect the board to your computer with a USB-C data cable.

   Open a tool that speaks Improv Serial (for example improv-wifi.com/serial/ in Chrome or Edge), or open a serial console connected to the board.

   Enter your 2.4 GHz WiFi network name and password. 5 GHz networks are not supported by any board revision.

   Once connected, the board displays its IP address in the serial output.

   Fallback hotspot

   If WiFi connection fails, the board creates a fallback hotspot called “Fan Controller Fallback”. Connect to this hotspot from your phone or laptop to reconfigure WiFi credentials.

2. Connect your fans

   • Connect your 12V DC power supply to the board’s power input (5.5x2.1mm barrel jack)
   • Plug your PWM fans (4-pin) into the fan headers (Fan 1 through Fan 4)
   • Check your hardware revision page for the correct pin layout and connector orientation

   USB-C does not power fans

   The USB-C port is for flashing and serial communication only. Fans require 12V DC power through the barrel jack connector. The USB-C port provides only 5V to the ESP32 microcontroller.

3. Adopt in Home Assistant

   Your fan controller is automatically discovered by Home Assistant via the ESPHome integration.

   • If you have the ESPHome add-on: The device appears in your ESPHome Dashboard. Click Adopt to add it.
   • If you don’t have the ESPHome add-on: Go to Settings > Devices & Services > Integrations. The fan controller appears under Discovered devices. Click Configure to add it.

   Once adopted, your fan controller’s entities (fans, temperature, humidity, RPM sensors) appear in Home Assistant ready to use.

   See Home Assistant Integration for dashboard setup and automation examples.

Re-flash firmware (optional)

You only need this section if:

• The factory firmware was corrupted (board will not boot or is not discovered on a fresh network)
• You want to reset to a known-good factory image
• You are installing a custom ESPHome build you compiled yourself

Most customers never need to re-flash. For routine firmware updates, use OTA through the ESPHome Dashboard. No cables needed.

Re-flashing uses the Web Serial API and requires a Chrome or Edge browser plus a USB-C data cable.

Rev 3.3

Flash Rev 3.3

See Rev 3.x hardware details for board specs and pin layout.

Rev 3.2

Flash Rev 3.2

See Rev 3.x hardware details for board specs and pin layout.

Rev 3.1

Flash Rev 3.1

See Rev 3.x hardware details for board specs and pin layout.

Rev 3.0

Flash Rev 3.0

See Rev 3.0 hardware details for board specs and pin layout.

Rev 2.0

Flash Rev 2.0

See Rev 2.0 hardware details for board specs and pin layout.

Rev 1.0

Rev 1.0 uses an ESP32 with a serial header instead of USB-C. You’ll need a USB-to-serial adapter (3.3V FTDI or similar) connected to the programming header.

Flash Rev 1.0

See Rev 1.0 hardware details for board specs and pin layout.

USB not detected? (ESP32-S2)

The ESP32-S2 (Rev 2.0+) has known USB reliability issues on some systems. Try these steps:

• Use a different USB-C cable (must be a data cable, not charge-only)
• Hold the BOOT button while plugging in the USB cable
• Try a different USB port (avoid USB hubs)
• Use ESPWEBTOOL as an alternative flash tool

After re-flashing, repeat the WiFi provisioning step above, then re-adopt in Home Assistant. See Firmware Updates for OTA updates.