Folks: I wrote an article on my blog about my differential GNSS (DGNSS) project. The article is mostly an annotated photo album. It took a while (so you’ll find this at the end of the article), but eventually I ended up using a pi-top  and a SparkFun GPS-RTK2 board with a u-blox ZED-F9P chip. The board fits nicely inside the . Might be of interest to the geolocation enthusiasts in the crowd. :Chip
Awesome project - definitely one to try out! Really liked the level of detail you went into with your trial and error iterations.
Just wondering how you managed to get the hub’s USB to work?
Mine will provide power to a connected USB device but no data exchange so, for example, my Pi-Top  is unable to “see” an attached USB mass storage device like a memory stick or SSD.
Did you have to “mount” the hub’s USB port in Terminal or settings?
I didn’t do anything special. As shown in my blog article, I have the SparkFun board with the GNSS module attached to the one internal USB port where it enumerates as a modem (ttyACM). I’ve used the external USB ports similarly. I’m not sure I’ve ever used a USB drive. But since all the USB ports on the Pi-top should just be extensions of the Raspberry Pi’s USB facility, I would expect it to “just work”. If I had that problem, I’d be inclined to pull out the Raspberry Pi and verify that a USB device works on its own USB ports without the Pi-top. Also make sure the Raspberry Pi is seated well on in the Pi-top, with the Pi-top’s USB connectors fitted into the Raspberry Pi’s USB ports. Good luck!
Some more thoughts: “tail -f /var/log/syslog” when you insert a USB device into a USB port, no matter whether it’s on the Raspberry Pi alone or when it’s on the Pi-Top with the Raspberry Pi installed. That will tell you whether it sees the device or not. I actually use USB drives seldom on my Raspberry Pis; typically I use “scp” to copy files to and from them over my WiFi network. So I can’t quite remember if Raspbian auto mounts USB drives. The system log can help diagnose that, plus doing a “mount” command afterwords to see if the drive shows in the list of mounted file systems. (I confess I do almost all my Raspberry Pi work on headless systems by using “ssh” to connect and doing everything by the command line. I’m an old school UNIX hacker.)
Thank you for the replies! Huh, so your hub’s USB worked right off the bat then… I don’t have a GNSS module to hand to test but if my Pi-Top won’t currently “see” an attached mass storage device from that port then I’d be surprised if my Pi-Top would be able to receive data from such a module. My Pi-Top does “see” attached mass storage devices when connected directly to USB ports on the Raspberry Pi, just not when connected to the hub’s USB port, which is strange because as you say it should be an extension of the RPi’s USB ports - but from comments I’d read and responded to on the previous forum, I don’t appear to have been the only person to experience this issue.
I’ll try your recommendations when I next have my Pi-Top to hand and report back! Thanks again