How not to Bryton your Day

With a three day bike ride planned as part of our trip, with several weeks to go, it's time to check in with the bike gear. The first thing I noticed was my trusty Knog bike computer is getting a bit long in the tooth:

In the dozen or so years since I got it, its never failed me: the batteries last for years, it automatically records the distance travelled each day, and clearly displays the current speed and distance travelled. However, with age its gotten cataracts, and along with the scratches accumulated over the years, the display is getting hard to see.

So it's time for a new one.  In addition to keeping track of speed and distance, since we will be riding in unfamiliar terrain, the one added feature that would be most helpful is an easy to see indication of the next turn.  Something like: 

3.7km  ⇒

to indicate when the next turn is, and the direction to go.  On paper, the Bryton S500 seems like an appropriate gadget: It's easy to read the display, has long lasting batteries that are USB-C rechargeable, has GPS, uses the open-source "open street map" maps, and supports standard ".fit" files for routes and navigation.  The reviews on the web claim that routes and directions can be uploaded via a USB cable, and I don't need an "account" on some website to use it.

Sadly it comes close enough to have caused me to spend lots of time trying to get the simple "how far to the next turn and what way to go" working, but has failed miserably on all accounts.  I will add the sordid details if I decide not to run it over, smash it with a hammer, and feed it to the garbage disposal.   Until then, if you wan't to use it for turn by turn instructions, my opinion is: DO NOT BUY it.!

Some minor points:

• For this model, the maps can only be downloaded and updated with a "desktop" app, which is unsupported on all computers I own
• The "fit" files are non standard and proprietary (and don't parse), so none of the usual tools (e.g. GPSbabel) will work, and so far Bryton won't provide me the format (I've asked)
• Although the device will show how far the next turn is, it doesn't provide the turn direction - you have to look at a teeny-tiny on screen map I can't see.
• You can trick the thing into providing direction arrows by entering them as "points of interest".  However they don't support any of the standard POI representations, you must enter them using the mobile app, which crashes often, loosing everything you've entered (well at least 5 times in 7 tries so far).
• The UI for entering POI's is virtually unusable, as the closest granularity I can get is about 2km, which is useless for "turn here" indications.  I managed to hook up a USB mouse to my phone, and set the lowest tracking resolution, and almost make it work. (I tried installing a "desktop android emulator" to make the data entry easier, but the app fails to save any of the POIs on it).
• Anything that interrupts the POI entering activity in any way, such as a call or message arriving causes it to lose any and all POI's entered so far.
• Did I mention POI's aren't editable once entered, and if you attempt to delete one and re-enter it, you risk loosing all the POI's.  Again!

Most of the negative reviews state the device is tricky to figure out, but works well once you've spent enough time figuring out the klunky UI.  While that might be true for the "knog" use case, it is absurdly bad for what I want it for, and if I wasn't so stubborn (and pissed at myself for wasting money on this thing), I'd have given up a while ago.  

Its a shame, as the hardware is fine: it seems whoever wrote the software went out of their way to make it unusable.  I suspect if they would document their data format (the device presents itself as a USB disk when connected to a computer), I could have written much better software in the time I've spent struggling with theirs.

You have been warned.