Fun with SD cards

[danham]

Here's an odd one. After adding a few new routes to my SD card in preparation for a big trip, my 660 began to refuse to read that card when using the My Data --> Import --> Routes function. It would read up to a certain point and then stop, displaying a maximum of about 8 routes, some of which were the new ones, but a few previous as well. All were stored properly in a GPX folder inside a Garmin folder.

OK, I made a backup of all data on the card and re-formatted it, figuring directory corruption, then copied all the data back onto it. No joy; exact same behavior. Next step, I figured there was a bad GPX file the zumo was choking on, and my trip routes were the new ones, so deleted them temporarily. No change except they didn't show and in their place there were a few more older files, but still only about 8 total. Next, I deleted a lot of the older files and put the new ones back on the card. Bingo, it all works properly, I see a few dozen routes to import, and I don't need those other files for the trip, so I'm leaving well enough alone. But WTF? It's not like the 32 GB card was even half full, though there were many dozens of GPX files and about 4GB of map data, all of which had been working fine in the past.

Any thoughts?

Thanks,

-dan

[kernowing]

Thanks for this post @danham I'm about to load some routes onto my 660 for an upcoming trip, hopefully I'll not need your solution

[rbentnail]

My thought:

How exactly are you adding routes to the card? I ask because my 595 would not work with routes placed on the card if the card was in the computer. I found that by having the card in the gps and using base camp to drag and drop routes to User Memory (the card) everything works fine. No file structure to keep up with, no formatting, nothing else ever had to be done except import from the card to gps internal memory.

[carolinarider09]

I am not an expert by any stretch of the imagination but I have had similar problems and found that there are lots of routes seemly stored out there on the device. I then figured that the software that runs the GPS might have some "limitations" on the number of files that can be used at anyone time. Seems like that number was something near 20.

Also, it seems that the routes might sort of be stored in other places and the affects the count. So, I have always tried to keep the number of routes on the device to those I need for a given trip with one or two exceptions.

[rbentnail]

I am not an expert by any stretch of the imagination but I have had similar problems and found that there are lots of routes seemly stored out there on the device. I then figured that the software that runs the GPS might have some "limitations" on the number of files that can be used at anyone time. Seems like that number was something near 20.

Also, it seems that the routes might sort of be stored in other places and the affects the count. So, I have always tried to keep the number of routes on the device to those I need for a given trip with one or two exceptions.

Yes indeed! I and many others have found that the device INTERNAL MEMORY can very limiting. I found you can have many routes stored in internal memory as long as you do not import them. The limitations seem to show up when we try to have too many imported routes at the same time, so I tend to import what I need for the day then delete it when finished. I don't leave unused data lingering around imported, it just creates problems later.

But for me, this is where using the SD card is so valuable. If a route is stored in internal memory, imported, used, then deleted, it is gone from the device. You cannot import it again. By deleting the route, you delete it COMPLETELY from the device so if you want to import that route again you'll have to transfer it again from BaseCamp (or your preferred map app).

OTOH, if the route is store on the SD card (USER MEMORY in BaseCamp), it can be imported and deleted and re-imported an unlimited number of times. And the number of routes stored on the card is limited only by the storage capacity of the card. Again, you have to limit the number imported at any one time but your routes are always available from the SD card whenever you choose to import them again.

[danham]

I am not an expert by any stretch of the imagination but I have had similar problems and found that there are lots of routes seemly stored out there on the device. I then figured that the software that runs the GPS might have some "limitations" on the number of files that can be used at anyone time. Seems like that number was something near 20.

Also, it seems that the routes might sort of be stored in other places and the affects the count. So, I have always tried to keep the number of routes on the device to those I need for a given trip with one or two exceptions.

Yes indeed! I and many others have found that the device INTERNAL MEMORY can very limiting. I found you can have many routes stored in internal memory as long as you do not import them. The limitations seem to show up when we try to have too many imported routes at the same time, so I tend to import what I need for the day then delete it when finished. I don't leave unused data lingering around imported, it just creates problems later.

But for me, this is where using the SD card is so valuable. If a route is stored in internal memory, imported, used, then deleted, it is gone from the device. You cannot import it again. By deleting the route, you delete it COMPLETELY from the device so if you want to import that route again you'll have to transfer it again from BaseCamp (or your preferred map app).

OTOH, if the route is store on the SD card (USER MEMORY in BaseCamp), it can be imported and deleted and re-imported an unlimited number of times. And the number of routes stored on the card is limited only by the storage capacity of the card. Again, you have to limit the number imported at any one time but your routes are always available from the SD card whenever you choose to import them again.

Exactly! This has been my strategy all along and it has worked fine until very recently. I will try the suggestion of dragging from BC to the SD card instead of from my computer to the SD card, but I am hard pressed to figure how that would make a difference. For now, it's working with the files I'll need for my ride, and so it's time to pack.

-dan