USB file I/O from python on WR41

Digi TransPort WR (Series)
1

I’m trying to get a python program to periodically append data to a file on a USB stick. I’m having two problems:

  1. despite opening the file per the instructions on the Digi.com web site (using A/gcp.log to indicate file gcp.log on the first USB device), the file is never written to the USB stick, but instead to the built-in flash.

  2. despite opening the file in append mode (using “a”), the existing data in the file is always overwritten.

I found something that appeared to be release notes for a firmware update that seemed to claim that the latter problem was recently fixed, but not for USB devices?

2

never mind. it appears that for this device the Digi python documentation is wrong about how you access files on the USB stick.

open (‘u:filename.ext’, ‘a’)

seems to work ok.

3

another note: apparently you can only have one file open on the USB device at a time?

4

I like this forum, amazing and very informative,