MTP - SD Read Only on Teensy 4.1

[N5NHJ]

I'm adding MTP support to my project and before doing it I'm experimenting with the example
https://github.com/PaulStoffregen/T...edia_Transfer/Basic_SD_Card/Basic_SD_Card.ino
The Teensy SD is discovered by the PC (OS is Win11), the files on the card show up but can't modified.
New files can't be written, looks like the SD card is in a "read only" status.
Any help?

 

[N5NHJ]

No help, Is it possible I’m the only one seeing this issue?
This SD is only 128MB, can this be a problem?
Thank you, any suggestions is really appreciated.
Max

 

[Angelo]

Test if the Teensy can write a file by itself ? You will know if the problem comes from the SD card, the Teensy or the library.

 

[N5NHJ]

Thanks Angelo,
Yes, the Teensy can read, write, and update the files.

 

[N5NHJ]

I got it working, more or less. The issue with editing and saving files on the SD card still remains, but I'm now assuming it's simply an MTP limitation.

Transferring files to and from the SD card works fine.

Kind of an off-topic question: is it possible to change the device name that appears in File Explorer from "Teensy" to something else?
Thank you, Max

 

[KurtE]

I am able to save files to my SD card on my Teensy 4.1

I dragged the file copper_in_chain.jpg from local folder to the SD Card folder.
And it shows up in my picture viewer.

Note: MTP is not a normal file system, where you can edit the files and the like. It instead is a protocol that is known by windows and the like,
where you can get lists of files and the like and you can transfers files back and forth. You can not edit the files directly on your SD Card.

Now with some files and apps, there is an illusion created, like you are able to do so. That is when you double click on a file, it downloads it to your PC in some temp directory, brings up the appropriate editor and when you do a save, the file system notices that the file changed and then uploads the changed version to the Teensy...

 

[N5NHJ]

Thanks @KurtE.
>>
Now with some files and apps, there is an illusion created, like you are able to do so. That is when you double click on a file, it downloads it to your PC in some temp directory, brings up the appropriate editor and when you do a save, the file system notices that the file changed and then uploads the changed version to the Teensy..
<<

That is indeed the part that doesn't work. Double click allows me to open the file - say with notepad, but the file can't be saved/overwritten to the SD directly. Needs to be saved somewhere else and then copied to the SD.