DEV Community: chinchilla Wikinson

How to Control Your Mini Split with a Microcontroller: Building a Wi-Fi IR Blaster for HVAC Automation

chinchilla Wikinson — Tue, 27 May 2025 06:19:21 +0000

Mini-splits are like magic in the world of air conditioning. They’re quiet, powerful, and don’t need ductwork. But here’s the strange thing: most people still operate them manually. With a remote. Like it’s 2005.

Now imagine this: you come home, and your ductless split system heat pump has already cooled the room to the perfect temperature. Why? Because it “knows” when you’re home. And that’s not sci-fi — it’s real with a microcontroller and an IR blaster.

Why automating your mini split is not a luxury but a necessity:

Energy savings: smart control cuts down your bills.
Comfort: the climate adapts to your schedule.
Remote access: control the system from the Maldives if you want.
Smart home integration: create scenes like “wake up – turn on heat.”
Ecosystem support: works with Home Assistant, Node-RED, and more.

The Basics: How a mini split and its IR control work

Most mini splits, even advanced ductless split system heat pump units, are controlled via infrared (IR) signals — just like your old TV. A microcontroller can emulate this signal and effectively “press” remote buttons for you. The trick is training the device with the right codes and ensuring a stable signal.

Core components of IR control for a mini split:

IR transmitter (typically 38 kHz)
Microcontroller (e.g., ESP8266 or ESP32)
Code library: IRremote, Tasmota, or built-in in Home Assistant
Proper transmitter placement — it must “see” the air conditioner

Popular mini splits brands that support IR control:

Mitsubishi Electric
Daikin
GREE
LG
Pioneer
Bravo
Olmo
Cooper&Hunter
Fujitsu

Tip: Even if your remote looks “analog,” in 90% of cases it transmits IR signals. Check this by pointing a smartphone camera at the remote — when pressing buttons, you’ll see blinking.

What you need to automate your mini split: List of components

To make your mini splits smart, you only need a few components and some enthusiasm. Everything revolves around the microcontroller and the IR transmitter. Essentially, you’re building an electronic “stand-in” for the remote, one that follows your rules, schedules, and logic from Home Assistant or other platforms.

You’ll need:

Microcontroller: ESP8266 or ESP32 — compact, powerful, Wi-Fi capable. ESP32 is preferred if using more sensors.
IR blaster (IR LED): standard 940nm IR LED + transistor to boost the signal. It will send commands to the air conditioner just like a regular remote.
Power supply: stabilized 5V source, ideally via USB or a dedicated power adapter.
Firmware: Tasmota, ESPHome, or even basic Arduino code. The choice depends on your platform (e.g., use ESPHome for Home Assistant).
Enclosure: optional but helps with aesthetics and protection. A 3D-printed case can make the setup look like a mini router.
Optional (but useful): temperature, humidity, and light sensors, IR receiver for learning remote commands.

Important: Place the IR blaster within the direct line of sight of the indoor unit of the ductless split system heat pump. Otherwise, the signal may not reach or be unstable.

How to Send IR Commands: Tasmota, ESPHome, Arduino, and Other Options

Sending IR commands is not magic — it’s precise engineering. Fortunately, the community has already done the heavy lifting. There are libraries and firmware options that know how to “speak” to specific mini-splits. Your task is choosing the right platform.

Option 1: Tasmota

Tasmota is prebuilt firmware that you can flash via a web interface. It supports sending IR commands via console or HTTP requests. Ideal if you want a quick setup without programming. Has built-in templates for popular brands.

Option 2: ESPHome

Perfect for Home Assistant users. Lets you write YAML configurations with commands like turn_on, set_temperature: 24°C, and mode: cool. A very flexible approach, easily expandable with automation logic (e.g., “if bedroom temperature >26°C — turn on cooling”).

Option 3: Arduino

For those who want full control. Use the IRremoteESP8266 library. It lets you both read commands from the remote and transmit them. A bit more complex, but ideal for custom setups, advanced logic, or integration with other systems.

Example logic: If the temperature sensor reads >27°C and someone is home — send a command to turn on the ductless split system heat pump in cooling mode at 24°C. If nobody’s home — don’t turn it on.

How to Build a Wi-Fi IR Blaster for Mini Splits: Step-by-Step Guide

Building your own mini split control system is easier than it sounds. The key is a clear plan and a few tools. Here’s what to do:
Gather components: ESP32 microcontroller, IR LED, resistors, transistor (e.g., 2N2222), power supply, and wires.

Assemble the circuit: connect the IR LED through the transistor to an ESP32 pin to boost the signal. Use a resistor to limit current and protect the LED.

Flash the firmware: we recommend ESPHome — just create a YAML config file and upload via USB.

Test IR signal transmission: you can use the A/C remote and an IR receiver on the ESP32 to “read” commands.

Configure integration with Home Assistant or another platform: connect the device to your Wi-Fi network, and set up automation.

Mount the IR blaster: aim it at the indoor unit of the ductless split system heat pump — without obstructions.

If something isn’t working, check your soldering and ensure the power supply is stable — this is where most DIY projects run into trouble.

Why Automating Mini Splits with a Microcontroller is Smart and Worth It

Sure, you could buy an expensive “smart” remote or a proprietary system. But the DIY approach with ESP32 and an IR blaster offers several unbeatable advantages:

Cost savings: instead of spending hundreds on branded accessories — just $10–20 in parts.
Flexibility: configure exactly the behavior you need, without extra features or pushy apps.
Integration: your mini-splits become part of the smart home, enabling complex scenes — from schedules to weather-based reactions.
Autonomy: once set up, no need to run for the remote — commands are sent automatically.
Community support: thousands of enthusiasts and open-source solutions — you can always find help or improvements.

In the end, you don’t just get an air conditioner — you get an intelligent climate system that saves energy and makes life more comfortable.

Rebuilding Economic Trust Through Local Digital Marketplaces

chinchilla Wikinson — Thu, 28 Nov 2024 14:26:28 +0000

It’s no shocker that large corporate entities continue their global decline, facing scrutiny from consumers unwilling to put their trust in the highly politicized corporations. According to the Edelman Trust Barometer 2024, less than half of people in developed countries trust businesses more than they do their governments. The same report also demonstrates that 61% of respondents believe business leaders intentionally mislead people.

People across the globe grow tired of unethical methods that corporations use to lure in more consumers. They desire a more transparent approach based on community-driven business models. This tendency will continue to escalate as large companies are willing to deceive the very customers they’re after. Inadequate promises, misleading marketing campaigns, and hidden advertising don’t help the situation; they only irritate the clients and make them look for something less deceiving.

Small Enterprises, Major Economic Force

That’s where small business comes into play. Their impact is much more critical than some may believe, and their contributions to restoring economic trust mustn’t go unnoticed. Nearly half of the American workforce is employed by small businesses, which contribute 43.5% to the nation's GDP. With over 33M US enterprises representing small businesses, they are a huge force to be reckoned with.

Smaller enterprises are way better at forming personal relationships with consumers. Their distinct ability to foster community trust gives them an upper hand over larger corporations. Times are changing as people grow tired of marketing tricks, one-time gimmicks poised to become the “next big thing,” and lack of transparency in corporate communication.

Cultivating Trust in Online Market Networks

Digital platforms like Nextdoor or AroundWire provide a healthier and more trustworthy alternative compared to soulless corporate entities. They give the people exactly what they want - an avenue for small businesses to
connect directly with local consumers, with no middlemen in between.

The Nextdoor Insights Report claims that 89% of platform users value neighbor recommendations for products and services, meaning that word-of-mouth still stands strong in the US, and people are more likely to pick a local business trusted by their friends or loved ones.

Hence, traditional advertising loses its grip as the community-driven approach gains strength, making every transaction more personal and reliable in the eyes of potential customers. For those in niche industries like locksmithing, platforms such as AroundWire offer valuable resources to help professionals find jobs and build their businesses effectively, as discussed in this article: https://proaroundwire.blogspot.com/2024/10/how-to-find-locksmithing-jobs-and-build.html.

Government Backing for Small Business Durability

During the COVID-19 outbreak, the government came out with various initiatives, such as the Paycheck Protection Program (PPP) designed to provide critical support to small enterprises nationwide.

Back then, more than $800 billion in loans was distributed to aid small businesses stay afloat and retain their staff. These efforts signify the importance of small companies for the national economy, underscoring their vital role in maintaining economic stability during crises like the pandemic.

Small-time enterprises are the backbone of American communities, and local digital marketplaces fortify the lifeblood of the US economy in a meaningful and impactful way.

A Catalyst for Economic Growth

Aside from a sense of trust and a community-driven approach, small businesses have broader economic benefits. In most cases, every dollar spent at a local business remains within the community. It helps boost infrastructure resilience and amplify employment rates. Digital marketplaces like Nextdoor encourage local spending, strengthening the bond between small enterprises and consumers.

These platforms take those relationships to the digital realm, where word spreads quickly, and consumers can compare various service providers and sellers to make the best choice in line with the collected info.

The Road Ahead for Economic Trust

The decline of corporate trust makes smaller businesses more visible, underscoring their pivotal role in rejuvenating the economy. Community-driven companies might fill the gap left by larger corporations. Their ability to foster transparent, local engagement restores consumer confidence and builds economic resilience during unpredictable economic changes.