I recently bought a Cubii under desk elliptical bike, I have two use cases for it:

  • Physiotherapy after a foot surgery
  • Help me to warm-up in my cold home office in the winter

Added bonus, doing light exercise. I definitely not find it as enjoyable as using a full size machine, or doing “real” sports, but this is just my preference and I am stuck at home with crutches anyway 😅

So my second hand model is a Cubii pro: no screen to display statistics, but with Bluetooth connectivity, which means that I had to install yet another proprietary app. I doubt usefulness of collecting those data but as it is BLE communications I wondered if it would be easy to reverse engineer the protocol by spying on the frames…
It appeared to be even easier to look into the Android application to find everything I need to dump the data into InfluxDB, and a fun weekend project.


I own a Rika Filo pellet stove, which I like, but it is on the expensive side of the market and the Wi-Fi module to remote control it was a no-go. This article describes the way I reverse-engineered the radio protocol.
As it is my sole heating system and winter is coming, I wanted a non invasive approach to avoid breaking anything, so I hooked up a logic analyzer to record the commands sent by the micro-controller to the radio chip, which helped me to learn the RF parameters + actual payload.


nfcAudio is an MP3 player, with audio files selected thanks to an NFC tag placed on top of it. I build this two years ago for my kid so he can play by himself his preferred nursery rhymes and songs, it is still used at least once a week :-)

It is powered by an ESP8266 to play audio from a remote server, an I2S DAC driving the speaker and an NFC reader. Thanks to WiFi we can use it to play local files or any webradio stream from the Internet.