I have installed the UV4L suite of software onto RPi3 with Jessie. I am using a USB cam (Logitech C170) rather than RPi cam. Configuration of UV4L seems to require an in-depth understanding of Linux and video, which I unfortunately dont have.

On bootup the streaming server at http://IP Addr:8080 displays fine but none of the camera streams on that site show an image. If I run "dd if=/dev/video0 of=snapshot.jpeg bs=11M count=1" I get "failed to open ‘/dev/video0’: Operation not permitted". If I change the device to video1 or video2 it runs successfully, but the resulting jpegs will not display in a browser.

I killed all of the u4vl processes (sudo was required), as I expect things were starting with the wrong defaults. After doing that I cant restart the server: when I run "uv4l -server-enabled" I get "[core] No device detected". So presumably I need to start the driver first. 

If I run "uv4l -–driver uvc" to start the core I get "No device detected". If I run lsusb I get the following:

    Bus 001 Device 006: ID 89e5:101b
    Bus 001 Device 005: ID 046d:c52b Logitech, Inc. Unifying Receiver
    Bus 001 Device 004: ID 046d:082b Logitech, Inc.
    Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
    Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.
    Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

If I try to start UV4L with the following

    uv4l -–driver uvc -–device-id 046d:082b

I get the error "<alert> [core] No device detected". I have played around with lots of other options. For example...

    uv4l -nopreview —auto-video_nr —driver uvc —encoding mjpeg —width 640 —height 480 —framerate 20 —server-option --port=8080

...returns the same result. I have searched around and found [this post][1] which does not have an answer either. Can anyone advise how I can restart the drivers manually such that I can test various config options and get it working with a USB camera?


  [1]: https://raspberrypi.stackexchange.com/questions/58012/uv4l-can-not-be-started-alert-core-no-device-detected