Slightly tired of big and long-running projects both at work and at home I decided to make a small spin-off project to help me working with ESP8266/ESP32 devices. Is there any reason to make it when there are a lot of cheap USB-Serial converters in the market? I don’t think so. My only reason to make it is to have cool addition allowing ESP8266s to be programmed automatically without flash/reset buttons but simple circuit with two transistors. Most of the USB to Serial converters simply do not have this circuitry on board. And, of course, I wanted to have some fun.

Spent a couple weekends deep-diving into a real FIDO2/WebAuthn implementation—and wow, it’s more complex than it looks. Ended up rebuilding the BLE GATT server on Android for better control. Got “Make Credential” working (video inside!), plus found a quirky Chrome spec mismatch along the way.

Got into a Reddit convo about showing JPEGs on e-ink displays with ESP8266—and turns out, you don’t need an external service to dither images. Just a bit of code magic in C++ or Python can convert JPEGs to black and white right on the device. Simple and fun!

Spent the weekend turning an ESP32 into a FIDO2 BLE Authenticator! Chrome even recognizes it (though it doesn’t do much yet). Also found a neat secure chip—ATECC508A—that could store encrypted keys. Still brainstorming how to handle more than 16 keys. Nerdy fun!

Ever heard of logging in without passwords? I stumbled upon the FIDO2/WebAuthn standard and it’s actually pretty cool—just your fingerprint and you’re in. I looked into how it works, its pros, and some open questions that still bug me (like… what if you lose the device?). Check it out!

While building my CO2 sensor, I wanted to manage the device over WiFi—no buttons, no cables. So, I made a sleek web-based config panel using VueJS and Tailwind CSS, all running right on the ESP8266. Here’s how I replaced manual setup with a modern, async, file-based config system.

Ever feel like the air in your room gets a bit… stale? I picked up a cheap MH-Z19b CO2 sensor and built a simple home air quality monitor using an ESP8266 and some DIY magic. Here’s how I prototyped it (twice!) and got it up and running with WiFi and colorful LED alerts.