View Single Post
  #19   Spotlight this post!  
Unread 05-01-2017, 16:28
s-taylor s-taylor is offline
Scott Taylor
FRC #1735 (Green Reapers)
Team Role: Mentor
 
Join Date: Feb 2014
Rookie Year: 2014
Location: Auburn, MA
Posts: 22
s-taylor has a spectacular aura abouts-taylor has a spectacular aura about
Re: Definitive Guide to Using the Jetson TK1/TX1?

One BIG thing for software updates:::
**DO NOT UPDATE YOUR UBUNTU O/S to 16.04 on host or on the Jetson!!!!**
(more on this in a moment)

I've been hoping to write such a guide this fall before the kickoff, but work (coincidentally at Nvidia) sort of overwhelmed me between Thanksgiving and New Years, and I don't have anything useful to report. I have written an initial guide for doing the software install, but have not yet gotten into the nuts and bolts of using the new Grip-generated pipeline class. It requires writing a wrapper around the generated OpenCV classes, and hooking into that from a camera source (can't use the new WPILIB cameraServer because that is only ported to work on the rio), and hooking it to a NetworkTables driver to send final target data to the Rio. My research thus far indicates the latencies should be fine if you are just getting your distance-to-setpoint (in degrees) from the coprocessor, and then using a gyro for fast feedback on your PID loop to get to the setpoint.

There is some conflicting info "out there" about what languages will support GPU acceleration in openCV. I'll be asking the local developers within the company for the DEFINITIVE answer w.r.t. Jetsons, and will put that in whatever docs I generate over the next couple weeks (Before I'm utterly buried by build season).

Back to the O/S upgrade comment: the systems currently require Ubuntu 14.04, and upgrading to 16.04 will render the system unusable (it disables all the USB ports, for one thing... so you can't actually log in and type anything to recover the system). You have to reflash, which turns out to be difficult given the requirements of having an Ubuntu14.04 host machine to do the flashing. I have a working recipe for developing a VirtualBox VM of the required Ubuntu image for re-flashing, and making the necessary passthroughs so a physical usb can be driven from the VM to the Jetson. It's not straightforward, and is not officially supported (The local team didn't even think it was possible...). I have a virtual disk image now, but it's surprisingly large (25G of content w/ all the jetpack installation stuff) and I have not yet succesfully transferred it from my work laptop to my personal laptop without errors. Still working on that.

16.04 support requires CUDA9 for some debians or somesuch, which isn't production (or even alpha) ready for Jetsons, so don't rely on having it for this competition build season. Thus, stay with 14.04 and don't ever let the onboard O/S do an update (like I did)!!!!!

That's about all I can say for now, and will (with any luck) get some better data/docs posted to this thread soon-ish. Sorry it's not ready for kickoff.

Last edited by s-taylor : 05-01-2017 at 16:33.
Reply With Quote