I shouldve joined stardance before i made the prototype
Why I Built This
A month ago I was prepping for a 25-day summer vacation, and every time I leave my house, my room literally turns into an oven. Leaving the AC running 24/7 destroys the electricity bill, but turning it completely off means returning to melted stuff, fried electronics, and dead room plants. So I built a smart ESP32 IR controller to manage the AC automatically while I was away—you just plug it into any regular 5V wall adapter to keep it powered continuously, and let it do its thing!
Coding the Firmware w/ Claude
Since the firmware needed to handle real-time MQTT, an OLED menu, schedule tracking, and saving IR codes, I used Claude to generate and structure the C++/Arduino code.Universal IR Remote Cloning: It has a “Register New AC” option right on the OLED. You point any factory remote at it, it decodes the IR pulses, and saves them straight to flash memory so it stays saved even after a reboot.Global App + Offline Buttons: I built a phone web app using Lovable + MQTT so I can check room temp and toggle settings from anywhere in the world. If the internet drops, there’s a 6-button physical menu on the device to control everything offline.
Auto Emergency Cooling: If the room temp hits 33°C, the ESP32 automatically kicks the AC on by itself so things don’t boil.
Hardware Fix: The Darlington Pair Boost:
During early testing, the IR LEDs couldn’t reach the AC unit across the room. After debugging the circuit w/ Gemini, I found out my transistor wiring was off. I fixed it by pairing the original 2N2222 with an S8050 to make a Darlington Pair. The extra current boost made the IR signal blast even further than the original factory remote!
25-Day Vacation Test & The $16 Price Shock
I left this messy breadboard setup plugged into a 5V phone adapter and running unattended for 25 straight days while on vacation, and it worked flawlessly without crashing once.Now I’m turning the prototype into an actual polished PCB (upgrading the cheap DHT11 to an SHT40) and was working for some hours on it and asked the component stock infos from gemini. But right when I went to order, the standalone RTC chip spiked the total bill by $16 cuz of component pricing! Next log: fixing the schematic w/ a cheaper RTC chip and starting the 3D printed case! in the future devlogs,i will post a vid which shows almost all the functions of the prototype.