Hi,
I tried to get the USB camera working last year and unfortunately that didn’t pan out. I am back again with a little more determination and motivation to get the camera to work.
Our camera:
A Logitech C270 USB camera
Our problem:
No video feed whatsoever in the Driver Station(and yes we did try switching every mode on the DriverStation). The camera appears in the roboRIO web dashboard as “cam1”.
Our forwarding code:
try:
self.camera = wpilib.USBCamera()
self.camera.startCapture()
self.camServ = wpilib.CameraServer()
self.camServ.startAutomaticCapture(self.camera)
except:
self.camera = None
The code is in Python but it should be similar to other languages.
Any suggestions or possible solutions are welcomed and very much appreciated! I have torn more hair out over this long issue than any other programming issue I’ve had.
I don’t have experience with RobotPy, but I think you need to specify the name of the camera when creating the USBCamera instance.
self.camera = wpilib.USBCamera("cam1")
Also, I don’t think you need to call self.camera.startCapture(), because self.camServ.startAutomaticCapture(self.camera) calls it for you.
My students wrote some code to use the USBCamera in RobotPy, but the USBCamera stuff is highly inefficient in python, if I recall correctly. Here’s a link to some of their code.
I’ve never tried sending it to the Driver Station… but I feel like I remember the students doing it, and it worked.
However, if you’re just trying to see the feed, I would recommend using mjpg-streamer instead. Here’s a CD thread about that: http://www.chiefdelphi.com/forums/showthread.php?t=135737
And here’s a gist that contains scripts to make it work.
And if you want to read the images from mjpg-streamer using python and process it with OpenCV, the repo listed above has a bunch of code for that.
I’ll be adding mjpg-streamer to the robotpy opkg feed for 2016, just haven’t gotten around to it yet. Hopefully by the end of this week or week one.
I think I will try using the mjpg-streamer on a Raspberry Pi 2 instead of the Rio. I don’t feel like messing with the Rio just days before the launch in case I brick the Rio. My only concern with the Raspberry Pi is when we are at the competition, how will I be able to consistently connect to where I will be streaming the video? Can I give a domain name to the Pi’s video stream so that I always can connect?
You could use AVAHI, the same multicast DNS technology that’s used to find the roborio’s DNS name.
Once I get it packaged and on the opkg feed for RobotPy, it should be pretty safe to install without fearing bricking the RoboRIO.