I decided to ratch an old exercise bike out of the shed in an effort to make more use of it in in the new year. It only took around a day or so for me to upgrade it a little.
I started by removing the existing cycle computer and replacing it with a laser cut mount for my Galaxy Tab, the logic being if I can still be doing stuff like reading articles and watching TV that I would otherwise be doing I would be more likely to actually use the bike.
Then to replace the removed cycle computer I used one of my spare Particle Photons to count pulses from the wheel switch and send data over MQTT.
I ended up just powering this from a USB power bank I had going spare.
I did plan to write a web front end to display the live data and possibly a script to run on my server to automatically submit data to Google Fit, but for now the data just feeds my OpenHAB server.