Your Bluetooth is bad, and you should feel bad
Alternate title: Your Bluetooth is OK, but it could be better
Just two gripes this time!
Always include a name.
I'm looking at you, Ruuvi. The Ruuvi sensors are interesting little devices. They started out back when the Eddystone protocol was an exciting new thing (fun fact: Copilot thinks there are still major Eddystone devices in the real world!), then made essentially the same sensors but with their own advertising format. And the Ruuvi company includes good documentation on their GitHub!
But ... why don't the tags advertise their names? Normally the way my app can tell one device from another is just from the name (and so far, without any overlaps) or for standard devices like Bike sensors, from the services exposed. Now I have to paw deep into every advertising packet just to see if an advert might be from a Ruuvi.
Use battery percentages, not voltages
Providing a battery voltage and not a percent, IMHO, is just weaseling your way out of a small bit of analysis. And it's an analysis that you, the maker, can do best.
There is no user out there who wants to know that the battery is at 2.45 volts. But everyone wants to know if the battery is running low. You can either do a conversion in your app, or you can just do the conversion on the device.
Not only that, but end users just expect a "ballpark" figure. This is confirmed by Microsoft, which expects devices to provide 11 steps (0..100% in 10% steps including the 0 and 100), and by the Bluetooth SIG which made the standardized battery levels.
