Easy communication between Raspberry Pi and roboRIO

[cantdecide]

The NetworkTables solution worked great, now we have bi-directional communication between the roboRIO and the Raspberry Pi. Thanks to the amazing team behind RobotPy and pynetworktables! You guys rock.

I have one question though. Is it viable bandwidth and latency wise to send image data over NetworkTables, or will I have to resort to a traditional HTTP server implementation for that? I'm asking because I'd like to display output from the OpenCV script in SmartDashboard but all the solutions I've seen for video streaming from Python use a basic web server implementation and I don't feel like I'd be able to pull that off without concurrency problems since I'm a novice at Python.

[virtuald]

pynetworktables has a latency of up to 50ms, and isn't designed for streaming data. NetworkTables3 (which pynetworktables does not support) ... might have support for that? But, probably not.

The HTTP approach would be best. I might get to something like that later in the season...

We had a crappy non-http server implementation that we prototyped last year. https://github.com/frc1418/2015-visi...chpad/rio-mjpg

[riftware]

Originally Posted by cantdecide

The NetworkTables solution worked great, now we have bi-directional communication between the roboRIO and the Raspberry Pi. Thanks to the amazing team behind RobotPy and pynetworktables! You guys rock.

I have one question though. Is it viable bandwidth and latency wise to send image data over NetworkTables, or will I have to resort to a traditional HTTP server implementation for that? I'm asking because I'd like to display output from the OpenCV script in SmartDashboard but all the solutions I've seen for video streaming from Python use a basic web server implementation and I don't feel like I'd be able to pull that off without concurrency problems since I'm a novice at Python.

My lead programmer wasn't sure how to get network tables installed on the Pi. We're a Java (or in a pinch c++ team) - does anybody have a reference on how to get them there? (or are they there to begin with?)

- Update - I found another thread that seems to show how to do it:
http://www.chiefdelphi.com/forums/sh....php?p=1525831 I'll try it tonight and update this post tomorrow.

[cantdecide]

Originally Posted by riftware

My lead programmer wasn't sure how to get network tables installed on the Pi. We're a Java (or in a pinch c++ team) - does anybody have a reference on how to get them there? (or are they there to begin with?)

- Update - I found another thread that seems to show how to do it:
http://www.chiefdelphi.com/forums/sh....php?p=1525831 I'll try it tonight and update this post tomorrow.

It really depends on which programming language you're using on the Pi. We use Python, so all I had to do was run "pip install pynetworktables".