Offloading data from a SD data logger?

[djsz]

I have a simple circuit that logs very low-density, occasional data to a micro SD card and would like some insight on how others have handled getting data onto a computer

I had implemented this on a Teensy 2.0 using the SD to MSC USB mode at it was great. I understand from Paul that this is unlikely to reappear for Teensy 3 in the same form.

Short of physically removing the SD card each time I wish users to access stored data, do you have any recommendations for designing a user-friendly way to offload data from a data logger? I've thought of hacking something together via serial, but that would require writing a client to receive. Just somehow grabbing the text files would be ideal.

I've considered excluding the SD card entirely, too, and just using the Teensy 3.1 flex memory. The data would easily fit (it's extremely low sample rate data), but would this be a crazy idea?

 

[MichaelMeissner]

One method is use the HID support instead of USB serial, and issue keyboard commands to copy the text to a file. On Linux you might have the Teensy emit the following as a keyboard:

cat > $(date '+data-%Y-%m-%d-%H-%M-%S.txt')
<datum #1>
<datum #2>
<datum #3>
...
^D

Replacing <datum-x> with a line of data. The ^D is a control-D character. Of course this assumes when the Teensy is connected, the user has a shell window open.