Help OTG problems reading multiple cards

[calail]

So, I have two phones - Samsung Galaxy S7 Edge and Samsung Galaxy S7. Both are running Nougat.

We use OTG cables and an SD card reader to view pictures on SD cards in the "field" through the QuickPic app (https://play.google.com/store/apps/details?id=com.alensw.PicFolder) . We've done this on Samsung S3s, S4s, & S5s (never had an S6) over the years. I've always plugged everything in, then when I was done viewing the photos, I unmounted the OTG/Card. All has worked effortlessly.

Now, on my S7s I have a problem. Typically, I can always read the first card I use on the OTG, but usually if I attempt to read a second card the phone won't see the card. I've tried it with "unmounting" (through settings) and just unplugging the OTG - sometimes it works, sometimes it doesn't. I've tried different cards, different SD card readers, different OTG cables. Nothing consistently caused the problem.

If I reboot the phone, most times I can read one card again - but typically not a second or third one.

While I use the S7 Edge primarily, I've had the same problem with the S7 although sometimes it will let me read two cards before it quits.

Any ideas?

 

[svim]

Do you use the same Google account on both your S7 and S7E? If so, instead of relying on Cheetah Mobile's QuickPic, switch over to Google Photos. With Google Photos that will auto-sync your photo library so you don't need to be juggling microSD cards, you just use the Google Photos app on each phone. Plus the added benefit of having your photos automatically backed up into your online Google account. You can then view your photo library on either phone or when you're on a computer just log into your Google account at https://photos.google.com

https://play.google.com/store/apps/details?id=com.google.android.apps.photos&hl=en

 

[calail]

Do you use the same Google account on both your S7 and S7E? If so, instead of relying on Cheetah Mobile's QuickPic, switch over to Google Photos...

While I appreciate your reply, another App (like Google Photos) isn't going to solve my issue. I pick up SD cards from cameras out in the woods. I am not near a location with PC, power, etc., and need to read the cards while standing there. I need a solution for the issue with the OTG.

 

[svim]

OK, this is another non-OTG suggestion so if OTG and adapters are the only solution that fit in with your workflow, just ignore the following also but since you're working with two Samsung devices there's also wireless transfer capability through NFC, I've found it more reliable to initially establish a connection when holding both phones within an inch or so, and then as long as both phones are about a foot or so apart there's still good throughput.
https://www.cnet.com/how-to/wirelessly-migrate-data-between-samsung-galaxy-devices/

 

[calail]

OK, this is another non-OTG suggestion so if OTG and adapters are the only solution that fit in with your workflow, just ignore the following .../

Thanks again! Actually, we typically just use the S7 Edge, I only mentioned the S7 as we've attempted it there to rule out a problem with the handset.

 

[calail]

Just more info in case anyone has been thinking about this - when my ORG doesn't display the pictures (whether using QuickPic or one of three others apps I've attempted I have foind I CAN see the usb/card reader in Astro File Manager. This isn't really helpful because I have to look at each photo individually and can't scroll through them all. So, why are photo apps not able to view the OTG?

 

[scary alien]

Kind of sounds like a mount/dismount issue to me...

Have you tried to make sure you "close" (swipe the app to the right in the app scroll list) the QuickPic app to make sure it's previous instance has really released it's open of the SD card.

Perhaps there's some combo of recent Android O/S changes and the QuickPic app that is making it behave a little less predictable than in years past.

If this works, you might want to contact the folks at QuickPic--or do that in either case--and discuss this issue with them--they might already know of this issue from others.

Let us know!

 

[calail]

Kind of sounds like a mount/dismount issue to me...

Have you tried to make sure you "close" (swipe the app to the right in the app scroll list) the QuickPic app to make sure it's previous instance has really released it's open of the SD card.

Perhaps there's some combo of recent Android O/S changes and the QuickPic app that is making it behave a little less predictable than in years past.

If this works, you might want to contact the folks at QuickPic--or do that in either case--and discuss this issue with them--they might already know of this issue from others.

Let us know!

I always *try* to remember to close QuickPic down, but don't actually CLOSE it through the battery settings (doesn't the right swipe just remove it from "recent apps" and not really close it?). Will attempt that and see if it makes a difference.

I have tried the same process with other photo gallery apps, and get the same results: works initially, but not consistently when attempting to view multiple SD cards.

 

[scary alien]

Swiping right is indeed a bit app-dependent (i.e., not all apps will behave or are written the same as far as what background processes they have and/or how they listen/interpret process notifications or the Android life cycle).

It's a bit cleaner and less invasive than outright killing it from the Settings -> Manage apps, which will work, but is not as simple or easy to do each time.

Android kills apps and processes on its own all the time (i.e., keeping the most used and most active ones "closer at hand").

I'm just thinking that the inconsistent behavior you've been seeing might benefit from at least trying this. Contacting the app creator still might be a useful exercise.

Cheers!

 

[efflandt]

I am not familiar with the swipe right or where app scroll list is. On my J7 I usually close individual or all open apps from bottom left button (Recently used apps).

I just tried plugging in a memory stick (rather than card reader), which automatically opened "MyFiles" (is that a general Android or T-Mobile specific ap?). It showed a thumbnail of an image on the memory stick which I could open to view by tapping on it. I closed out MyFiles (using bottom left button on the phone), disconnected the OTG and reconnected it with different memory stick with an image on it. That similarly opened MyFiles with thumbnails of what was on the 2nd memory stick, and I could tap to open an image. So my J7 which is a stripped down version of the S7 does not exhibit your issue.

Also not familiar with QuickPic. My phone came with something called "Gallery" for normally looking for photos on the phone whether from the camera, screenshots, downloads, etc. and can show a group of smaller images, bigger than the thumbnails in MyFiles.

 

[calail]

I appreciate the replies and have the following to add: the phone exhibits the same behavior whether or not I close the app. Sometimes it works, sometimes it doesn't.

The same is true whether I use QuickPic or the default gallery app.

I'm really at wits end. I feel likes the OTG sensor is just not working properly.

Any other ideas?

 

[svim]

Going back to a comment @scary alien made about this simply being a mount/dismount issue. Do you indeed use 'Unmount' each time you remove any microSD card? If not, start doing so as the file system that cards use, FAT (File Allocation Table), is relatively fragile and easily corrupted. This also gives the operating system itself notification that the card is no longer accessible.

 

[calail]

Going back to a comment @scary alien made about this simply being a mount/dismount issue. Do you indeed use 'Unmount' each time you remove any microSD card?

 

[calail]

Actually, it works less if I unmount the card, as if it doesn't see the newly mounted card after wards [the second card].

 

[lunatic59]

Just thinking out loud here. When you swap SD cards, do you unplug the OTG cable or simply eject the card from the reader? I'm wondering if the S7 is having trouble with the card itself or just the reader?

 

[calail]

Typically, I unplug the OTG cable. I may not read another card for 30 m8nutes as I leave that location and drive to another.

 

[lunatic59]

What brand/make of cable? What camera format? ( I want to try a little testing with my wife's S7E)

 

[calail]

What brand/make of cable? What camera format? ( I want to try a little testing with my wife's S7E)

Thanks for your reply!
So, the cord is nonbranded. I have 4 different cords and have the same problem regardless. They are short microUSB to SUB cords.

I also have several SD card readers; a Targus one, and a generic one.

The cameras are Trail/Game cams, and photos are JPGs copied to a SanDisk 8g Class 10 card, in a DCIM folder on the card.

I have a few other cards, but this is the most common.

I have not been able to isolate my issues to any single cable, reader or card.

 

[lunatic59]

Okay, since it's across multiple readers, cables and cards, then I don't think we've got a specific culprit there. I have a multicard reader here with a couple of generic OTG cables, but the wife is away for a day so I'll have to wait until she gets back to test. I'll try some SD cards from Nikon and Fuji cameras, which all do the DCIM/jpg thing. Probably tomorrow or Thursday, if you can hold on that long.

 

[calail]

Okay, since it's across multiple readers, cables and cards, then I don't think we've got a specific culprit there. I have a multicard reader here with a couple of generic OTG cables, but the wife is away for a day so I'll have to wait until she gets back to test. I'll try some SD cards from Nikon and Fuji cameras, which all do the DCIM/jpg thing. Probably tomorrow or Thursday, if you can hold on that long.

L59, I would appreciate any insight you might be able to provide.

As noted in the OP I have the same problem with my Galaxy S7 [non-edge]. I'm ready to tear my hair out, but I won't go bald for a few days

 

[lunatic59]

just to be thorough, this problem only arose with the S7's running Nougat? Did the EVER work normally or has this been a "day one" problem?

Are you running stock? (No rooting or mods of any kind?)

I have an LG G6 and a Chinese off-brand phone both running Nougat as well, so I'll give those a test as well to see if it's an Android 7.x issue or something unique to Sammy.

 

[calail]

It's been a Day One problem with these S7s however, they've always been on Nougat - They were new when activated a few months back and updated to Nougat right away.

Neither phone is rooted and are on Verizon network.

 

[Nazakit HUssaiN]

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[lunatic59]

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I'm not sure I understand the question. Could you be more specific?

 

[lunatic59]

Well @calail, I don't think you're going to like my results. I tried a bunch of different scenarios with three different phones all running Nougat. I took two devices, a multi-card reader with a 16 GB SD card in it and an old USB 2.0 flash drive. The SD card came right out of my Nikon D3200 and the flash drive was just some random files (including images).

I plugged my OTG adapter(s)* into each phone with USB device attached. In all cases the device was recognized and the files were available, I then proceeded to hot plug the adapters from one device to the other without unmounting them first. At one point I was prompted with a warning to unmount USB devices first to avoid data loss, but they were still all recognized when re-inserted. I also tried unmounting properly and then remounting. I did this about three times and not once was any card/device failed to be recognized.

*Had to use different adapters because the G6 and the Chinese phone both have USB Type-C connectors while the S7 still uses the micro type-B plug.

I'm not sure what to tell you other than it's not an Android 7.0 or a Samsung S7/Nougat problem. I have a couple of suggestions.

First since you say your phone(s) updated to Nougat right after you got them, you might want to consider a factory reset. We've seen many times where major version upgrades will leave bits of the old OS lingering around with unpredictable results. The other thing I might suggest it to replace your OTG adapter. Since you say you use these quite a lot, it's possible that the connector or wiring is either shorting or broken to the point of making intermittent connections. Or, it might just be ever so slightly incompatible so that it works the first time, but borks the connection after you remove it.