Aeolus

Aeolus

Aeolus is a smart, temperature-aware IR fan controller built around an ESP32-C3. It watches room temperature and automatically turns a WOOZOO (or other NEC-protocol) fan on and off over infrared, with a 0.96" OLED status display, a physical control button, and an on-device IR "learn" mode for capturing new remote codes — all on a custom-designed 4-layer PCB.

Named after Aeolus, the keeper of the winds.

Gallery

3D render

PCB layout (4-layer, black soldermask, silkscreen branding)

Schematic

Background — this is v2 of my fans project

Aeolus is a ground-up redesign of my earlier dorm-room fan automation project. The original ("fans") was an Arduino Uno R3 on a breadboard: a DHT11 sensor, an IR receiver, and a transistor-driven IR LED that automatically toggled the fan on hysteresis. It worked, but it was bulky, code-only, and limited to hardcoded remote codes.

Aeolus keeps the proven control logic and rebuilds everything around it as a real, compact, hardware product.

Design improvements over v1 (fans)

The transistor-buffered IR transmitter (the key range fix from v1 — extends usable range from a couple of inches to ~10–15 ft) is carried over into the Aeolus hardware.

Hardware

• ESP32-C3 SuperMini microcontroller module
• 0.96" SSD1306 OLED (I²C, address 0x3C)
• NTC thermistor on the ADC for temperature sensing
• IR receiver (38 kHz demodulating, VS1838B-style) for learning remote codes
• IR LED (940 nm) transmitter, transistor-buffered for range
• Momentary push button for manual control / mode switching
• Custom 4-layer KiCad PCB (hardware/Aeolus.kicad_pcb / .kicad_sch)

Pin map

Firmware

The firmware lives in src/main.cpp and is built with PlatformIO (Arduino framework for ESP32-C3).

• Automatic control with hysteresis — fan turns on at 75 °F, off at 73 °F, so it won't rapidly cycle around the setpoint.
• Minimum run time — once the fan starts, it stays on for at least 10 minutes.
• Two operating modes — a normal run/monitor mode and a scan (IR-learn) mode, toggled from the button.
• IR learn mode — point your fan remote at the receiver and Aeolus captures the raw NEC code so it can replay it later.
• OLED UI — shows current temperature and fan state with animated wind (fan on) and snow (idle/cool) effects.
• Sends NEC-protocol IR commands (default is the WOOZOO fan power code).

Build & flash

This is a PlatformIO project:

pio run              # build
pio run -t upload    # flash to the ESP32-C3
pio device monitor   # serial output

Board and framework are configured in platformio.ini. Libraries used: IRremote, Adafruit SSD1306, Adafruit GFX.

PCB & hardware design

The KiCad 9 project is in hardware/ (schematic, PCB, custom symbol/footprint libraries). Highlights:

• 4-layer board — SIG–GND–PWR–SIG. In1.Cu carries a poured GND plane and In2.Cu a poured +3.3V plane. Every ground and supply pad is through-hole, so the plated barrels tie straight into the planes with thermal reliefs and no stitching vias are needed. That is why there is not a single GND trace on F.Cu — the plane carries every return, which keeps the loop area of the switched IR LED current away from the high-impedance thermistor sense line.
• Custom ESP32-C3 SuperMini symbol and footprint, pin-labeled to match the actual module.
• Custom silkscreen branding (the "Aeolus" wordmark) generated from the artwork in branding/.
• 3D models for the ESP32-C3, OLED, and IR components in hardware/Aeolus.3dshapes/ for a complete 3D render.

Known limitations

Stated up front so the files and the description agree:

• Signal routing is single-sided. All 75 copper segments sit on F.Cu; B.Cu is unused for routing. This is fine at this node count because power and ground are handled by the inner planes rather than by surface traces.
• No decoupling capacitors are placed. schematic-guide.txt calls for 100 nF on the OLED and IR receiver supplies; those parts are not yet in the schematic.
• No I²C pull-ups on the board — the design relies on the ones fitted to the OLED breakout.
• The board has not been fabricated. Everything in hardware/ is layout and 3D render only; no gerbers, BOM, or assembled unit yet.
• The IR range figures are estimates, not instrumented measurements.

License

See LICENSE.