Undoubtedly, the ESP8266’s biggest selling point is its WiFi capability for a ridiculously low price. Paranoid folks probably await the day its closed-source firmware bits will turn against humanity in a giant botnet, but until then, hobbyists and commercial vendors alike will proceed putting them in their IoT projects and devices. One of those devices is the Yeelight desk lamp that lets you set its color temperature and brightness via mobile app.
[fvollmer] acquired such a lamp, and while he appreciated its design and general concept, he wasn’t happy that it communicates with external servers. So he did the only reasonable thing and wrote his own firmware that resembles the original functionality, but leaves out the WiFi part. After all, the ESP8266 has still a lot to offer in its core essence: a full-blown 32-bit microcontroller with support for the most common, hobbyist-friendly SDKs.
The lamp’s color temperature and brightness are set with a rotary encoder / push button combo switch, and the LEDs themselves are controlled via PWM. All things considered, it’s a rather straightforward endeavour, for which [fvollmer] chose the standalone C SDK. And in the end, it’s not like he’s unreasonably cautious to keep some control over his household items.