This is not an SD card, it is a USB thumb drive.
I formatted a different USB thumb drive on the RCA. My Mac says it is formatted "MS-DOS (FAT32)", just like the other one. I put a file onto it. It behaves exactly the same as I described in my original post -- no joy.
Since the Android File Manager app does not see the USB drive, I don't know how to copy files from it to some place where MSP could see them.
I have a USB adapter for an SD card. I put my files from my Mac onto an SD card and then plugged it into the RCA -- MSP could import just fine from it. I then plugged it into a Hanspree tablet, and MSP failed to find it (just like the USB drive in my original post). Putting the SDcard into the USB adapter and plugging that into the Hanspree OTG worked. Both tablets run MSP 3.3.7 from the Play Store.
So it looks like my hopes of a single workflow for all tablets fails. USB thumb drive is close, SD card with USB adapter is close, Companion app is close, but no success for any of them on all tablets.
In the future I'll probably use the SD card with USB adapter, as that's easier than jumping through the hoops required to use the Companion App on the HP 2-in-1 Chromebook.
I formatted a different USB thumb drive on the RCA. My Mac says it is formatted "MS-DOS (FAT32)", just like the other one. I put a file onto it. It behaves exactly the same as I described in my original post -- no joy.
Since the Android File Manager app does not see the USB drive, I don't know how to copy files from it to some place where MSP could see them.
I have a USB adapter for an SD card. I put my files from my Mac onto an SD card and then plugged it into the RCA -- MSP could import just fine from it. I then plugged it into a Hanspree tablet, and MSP failed to find it (just like the USB drive in my original post). Putting the SDcard into the USB adapter and plugging that into the Hanspree OTG worked. Both tablets run MSP 3.3.7 from the Play Store.
So it looks like my hopes of a single workflow for all tablets fails. USB thumb drive is close, SD card with USB adapter is close, Companion app is close, but no success for any of them on all tablets.
In the future I'll probably use the SD card with USB adapter, as that's easier than jumping through the hoops required to use the Companion App on the HP 2-in-1 Chromebook.