Thursday, September 10, 2020 at 14:36:04
I’ve just started doing some audaxes and whilst GPX routes are often supplied, you can often start at any point. This made me wonder whether you could follow a route on the Bryton Rider 450 from any point along it. The good news is that - yes - you can, however that comes with one major problem. When you get to the end of the route the map screen goes blank and tells you you’ve “Arrived”. What I want it to do is just carry on from the beginning again which the Rider 450 won’t do. This is perhaps unfair behaviour to expect of it and maybe an “edge” case, which means the route would have to be digitised again for your starting point.
The tracklog does carry on recording and this goes to show that the tracklog and map routing are completely separate activities running in parallel on the device. Precedence is giving to tracking as this is highly time dependent. It explains why the maps take time to refresh and the longer the routes get, the longer they take to load. This can at times can give the impression that the unit has frozen, when in fact it’s reading the whole route back in to memory, taking the current GPS coordinate, loading the correct map tile, then plotting the breadcrumb trail over the top. On one ride, I had started following a route, but for the first 20km rode using the data screen as I knew the roads to follow, I then switched to map view and the Rider 450 took more than 5 minutes to refresh the map. This would suggest to the rider that it was frozen, but the distance and cadence fields were live, so it was clearly working. My guess is that it records the last map shown on the route and then iterates through every position along the route until the it matches the coordinates from the GPS, then refreshes the tile. This is hugely inefficient, particularly for long routes but simple and probably computationally easier to accomplish at the expense of significant time.
It also further highlights that the map screen doesn’t refresh until new information is ready to display, again behaviour that might suggest it’s frozen (and indeed it may lockout other actions until this is complete). Crucial to this series of events is being able to get a GPS coordinate: if it can’t do that, the map won’t update. This means that if your system can’t get satellite lock (in a tunnel, under trees etc) then the maps remain frozen until a coordinate is supplied. The tracklog however should carry on recording (doing whatever the recording algorithm dictates for a lack of current coordinate) in these situations.
The key then is patience and just carry on cycling with one BIG caveat. If you genuinely do have a frozen Rider 450 then it will need rebooting! Remember that means pressing and holding the four side buttons for a few seconds, then releasing them. Once rebooted it then needs to go through the whole process of satellite lock and getting a first coordinate - this can take minutes the first time after a reboot. I have also tried waiting on a number of occasions and once it carried on working and on the other the unit remained frozen. The latter problem came when I suspect the unit didn’t have satellite lock and I tried to change from the map to data screen (or vice versa) freezing operation. It is possible that this is a genuine bug that crashes the unit and I can definitely say the tracklog doesn’t carry on recording. The only solution is a reboot, which is certainly necessary if you want to use the maps/data.
I’ve also noticed that refreshjng the map and the lap timer can well conflict. My timer is set to a fairly rapid 2km (4-5 minutes) and the map often tries to refresh when the timer is due to roll over. The latter is given precedence which again freezes the map display. My best guess at the moment is don’t try to switch in/out of the map screen when this is about to happen.
A later post will talk about what to do with the corrupt files!