Definitely an odd device that it doesn't seem to make accessing the data without hacking into the bluetooth stream data, but this was pretty awesome.
to the author: Did you end up graphing / recording the data or just displaying it while you played?
to the author: Did you end up graphing / recording the data or just displaying it while you played?
The Bluetooth spec defines a large variety of common types of data streams (including things like friendly device names and battery status), as well as open areas where vendors can cram their own, purpose specific stuff.
It's quite easy to use, once you learn the setup. And once you learn the specific API your combo of programming language and operating system use to communicate with BLE, everything about consuming a device is otherwise identical, so you can create libraries that consume specific types of data streams quite easily.
EDIT: typo
But I agree it's an odd device. If one wants more precision than the optical sensors found in smart watches, using a HR belt would be the logical choice?
The advantage of these standalone optical sensors is that because they are smaller & lighter, and sit on the fleshier upper arm, they are much more accurate than sensors on a watch, despite being the same tech.
Edit: DC Rainmaker's analysis shows that these are more or less as good as a chest strap (https://www.dcrainmaker.com/2019/03/polar-oh1-plus-optical-h...)
I'm trying to figure out how to render a graph inline, but its more complicated
- simple Android app capture heart rate data over bluetooth from a polar chest band
- send the data up to a server and pipe it into influxdb database
- display using grafana
It was very useful to show when I was having an episode. I tried all sorts of things to identify the triggers, in the end it turned out to be alcohol (duh!).