compareeHub

A DEAD AIR CONDITIONER WI-FI MODULE REPLACED WITH A 5 DOLLAR CHIP

When his GREE air conditioner's Wi-Fi module died, Bill Kolicoski brought it back into Home Assistant with an ESP-01, an IR LED and ESPHome's climate component.

by Bill Kolicoski (Taste The Code)

FULL CAD BOM FIRMWARE DOCS

HomeAutomation

Built with3D printing

difficulty
●●●○○
time
a weekend
license
license not specified
repo
repo 0 stars

WHAT YOU’LL NEED

Videos
1
Jump to section

COMPAREE VERDICT

This is a practical rescue for a specific problem: a dead Wi-Fi module in a GREE air conditioner. Bill Kolicoski tried the obvious path, capturing and replaying raw IR codes, and it failed. The breakthrough was ESPHome's IR climate component, which already knows how to speak GREE's protocol. The final device is tiny, an ESP-01 with an IR LED and a step-down converter, tucked on a shelf. It works exactly like pressing the remote, and Home Assistant shows the room temperature and lets you set the mode and target temperature. The hardest part is not the soldering or the print, it is finding the right protocol for your exact AC model. If Home Assistant is not already running, set that up first; if your AC is not a GREE, check that ESPHome's climate IR component supports your brand before you start.

GOOD TO KNOW

  • —ESPHome YAML for the IR transmitter, room-temperature sensor and GREE climate sections, plus the written guide, are on tastethecode.com; you add your own board and Wi-Fi sections.
  • —3D printable case on MakerWorld (model 2000408), licensed CC BY-SA.
  • —No formal BOM, but the guide lists parts with AliExpress affiliate links.
  • —No licence stated for the YAML config.
  • —Requires a working Home Assistant instance and ESPHome already installed.

Parts to buy

7 items

From our check of the build. Exact quantities and part numbers are in the creator’s BOM.

  • ESP-01 moduleFind
  • IR transmitter LEDFind
  • IR receiver (for testing)Find
  • 5V to 3.3V step-down converterFind
  • 5V power brickFind
  • PerfboardFind
  • WiresFind

Can I build this?

Printsmall case for the ESP-01, IR LED and step-down module (MakerWorld 2000408)
BuyESP-01 module, IR transmitter LED, IR receiver (for testing), 5V to 3.3V step-down converter, 5V power brick, perfboard, wires
ToolsESP-01 USB programmer, soldering iron, 3D printer, Home Assistant server with ESPHome add-on already installed
Skillsbasic soldering, ESPHome YAML editing, Home Assistant integration, 3D printer operation; assumes familiarity with Home Assistant's interface
Timea weekend if Home Assistant is running; add another evening to install HA and ESPHome if starting from scratch
Cost$ — the video title calls it a $5 chip; the guide gives no total, and its parts list uses AliExpress links.
SafetyLow-voltage DC only (3.3V and 5V). No mains work, no lithium cells, no lasers.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

Videos

I Hacked My AC Remote with a $5 Chip (ESPHome IR Blaster Climate Control)15:42

Walkthrough of the failed prototypes, ESPHome config discovery, and final assembly

More builds like this

All projects
A used robot vacuum freed from the cloud — it now runs fully offlineHomeTake your router back from its makerHomeYou can control your Chamberlain garage door locally, without the cloud, with a small open-source boardHome

Gallery

Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Confirm your air conditioner brand and model (The guide's YAML uses the GREE platform with model yac1fb9; yours may need a different model.)
  2. 2.Install Home Assistant and the ESPHome add-on(If you do not have these running already, expect another evening of setup)
  3. 3.Order the ESP-01, ESP-01 USB programmer, IR LED, step-down converter and, for testing, an IR receiver (The guide includes AliExpress affiliate links for all parts)
  4. 4.Flash the ESP-01 with the ESPHome config (You will need an ESP-01 USB programmer; the guide shows a switch trick for boot mode)
  5. 5.Add the device to Home Assistant and test on/off from the dashboard(This is where you discover if your protocol string is wrong; be ready to try others)
  6. 6.Print the case and assemble the final device (The author's first lid was too tight; the guide describes enlarging the tolerances.)

Resources

Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.

KNOWN ISSUES

  • The ESPHome GREE platform offers several model protocols; the author found the right one (yac1fb9) by trial and error, testing each until the AC turned on.
  • The ESP-01 has very few usable pins. The guide's YAML sends IR on GPIO3, so update `pin:` if you wire the LED elsewhere.
  • The ESP-01 needs a steady 3.3 V. The build uses a small DC-DC step-down module from a 5 V power brick, so do not feed it 5 V directly.
  • Home Assistant and ESPHome must already be installed and working. This project is not a good introduction to either; it assumes you know how to flash a device and add it to HA.
  • The IR LED needs a clear line of sight to the AC. If the shelf is too low or blocked by furniture, commands will miss.
  • The author's first printed lid was too tight because the LED wires push back; he enlarged the lid tolerances and reprinted it, so check the fit of your print before closing the case.

Will this work with my air conditioner?

Only if ESPHome's IR climate component supports your brand and model. The guide uses the GREE platform with model yac1fb9; check the ESPHome climate IR documentation for your brand before ordering parts.

Do I need the IR receiver after the first test?

No. Kolicoski used it to try decoding the remote, but once the ESPHome component worked, the receiver was no longer part of the final device. It is useful for debugging, but not required.

Can I use a different ESP board instead of the ESP-01?

Yes. In the guide the climate component first worked on an ESP32; the ESP-01 was chosen for the final build because it is tiny. Any ESP8266 or ESP32 board that runs ESPHome should do the job, with the IR LED pin changed in the YAML.

Does this replace every function of the original Wi-Fi module?

The guide shows on/off, mode and temperature control from Home Assistant. The bridge only sends infrared, so the AC does not report its state back; the room temperature comes from a separate Home Assistant sensor.

What is the range of the IR LED?

The guide does not give a range. In the build, the device sits on a shelf in the corner of the living room, directly across from the AC with a clear line of sight.

Community builds

No community builds yet — be the first, we feature the best ones.

Discussion1

FROM THE COMPAREE TEAM

If you have tried this on a different AC, which protocol worked, and how many did you test first?

CompareeTEAM4d ago

Practical notes from our verification: the guide is honest about the failed attempts (raw code capture on NodeMCU and ESP32) before the ESPHome climate component worked, which is rare and useful. The author reprinted the case lid with looser tolerances because the LED wires added spring. The case on MakerWorld is CC BY-SA; no licence is stated for the YAML config. The ESP-01 is the final minimalist version; the NodeMCU and ESP32 prototypes are shown in the video but not needed if you go straight to the working config.

Bill Kolicoski (Taste The Code)

Bill Kolicoski runs Taste The Code, a site and channel focused on practical electronics fixes and smart home integrations. This project came from a real failure in his own living room, a dead GREE Wi-Fi module, and he documented every wrong turn before finding the ESPHome climate component that made it work.

GitHub Web

Star the project on GitHub

DISCLAIMER

  • Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
  • Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
  • Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
GitHub repo