Hello,
- Make sure Data collection is enabled (Router UI -> Services -> GPS -> NMEA) and try filepath /mnt/sda1/yourfilename.txt
- By default sda1 folder is created, but you should double check by connecting with SSH or simply connecting to router web UI -> System -> CLI (login: root, Password: router password) and inputing "ls /mnt" command. This will display usb content, including newly created folder.
- Both FAT32 and NTFS formats should work.
Regards,
TomasM