Wednesday, 11 July 2012

Continuing in my better running through technology phase that I'm currently going through, I got all excited when I discovered that Polar make a Bluetooth-enabled heart rate monitor chest strap.

Prior to this, I'd be lamenting how there wasn't a large choice of ANT+ enabled Android phones (to my knowledge there's just something Sony makes)

So I got all excited and ordered a strap and it arrived today. This is my initial review (I haven't gone running with it yet, I've just had a tinker)

I'll start with the bad first

the battery cover is a bit dicky

I took the battery cover off to confirm it came with a battery and then had a whale of a time getting it back on. I haven't managed to get it on as flush with the back as before I took it off. This appears to be a common complaint in the Amazon product reviews also.

hard to tell what its auto off timeout is, whether it's on, etc

Basically there's a large lack of feedback as to what's going on. Is it on or off? Is it wet enough to turn itself on? Is it reading a heart rate, or is the Bluetooth pairing just not working? The most accurate way I've found to determine if it's "working" or not is to unpair it and then repair it again. If you get a PIN prompt it's talking. By accident, I've found indications that it will turn itself off after not reading a heart rate for 10 minutes, and to reset it, you detach it and wait 30 seconds and reattach it. This would have been good information to include in the manual

Now for the good

reasonable Android app support

Heart Rate Monitor for Polar claims to support it, but I haven't managed to get it to do anything useful yet. I was pleasantly surprised to discover that My Tracks has support for it. Noom CardioTrainer is one that I was already trying out alongside Strava Run (which doesn't have support for it). There's also Sports Tracker and Endomondo. The UI for both of these also show the battery level. I've found that trying to have multiple apps reading the heart rate monitor simultaneously seems to be an exercise in fail, and that the Sports Tracker app seems to start a background service which subsequently causes all sorts of problems for any of the other apps started after it has started.

And the ugly

Looking back at all the Amazon product reviews, they're pretty much split equally between 5 stars and 1 stars. The product seems to either work flawlessly or absolutely dreadfully. I was beginning to think I was in the latter group and that I'd bought a white elephant, but now that I've gotten to the bottom of the idiosyncrasies of talking to it from Android, it seems to be behaving fairly reliably.

Talking to it from Linux, and the reason behind the title of this post

One of the first things I tried doing after Android was being initially flaky for me, was to try and talk to it from a Linux laptop. This proved fairly straightforward using rfcomm. I didn't get anything human readable out of it though. Being curious as to how these Android apps were able to decode the data, I went looking for some API documentation, and a Google search led me to this sad forum discussion.

So the API information is not freely available, and their CEO personally signs off on who gets access to it. How ludicrous. Do they want to sell product or not? That said, I did also find this blog post which, courtesy of the aforementioned Open Source My Tracks Android app, lays it all out for you. So them being all anti-development with their information is kind of pointless. Polar's website doesn't mention anything about their management, so I have no idea who their CEO even is. Wikipedia is also none the wiser.

I'm looking forward to going for a run tomorrow and seeing how this thing pans out.