Wednesday 5 September 2012

Moving on from the realm of DVB-T with the RTL2832U - Undoing your hard work

So, you may have read my last (and also first) blog post on getting the RTL2832U-based dongles working with Ubuntu and wondered what might be next. Before I start dissecting all the possibilities, I thought it best to explain what needs to happen before you start moving in that direction.

If you've followed the guidelines in my first post, your system will now be in a state where the required DVB-T modules are auto-magically loaded upon hot-plugging your RTL2832U dongle. This behaviour doesn't play well with GNURadio, RTL-SDR and OsmosSDR; and you'll be needing these to fully unlock the potential of your new toy.

You need to unload the modules that have been loaded. There are a whole load of DVB and infra-red modules that hog the device, that can be removed with a handful of commands, allowing you to run the aforementioned applications and libraries comfortably. To save you the effort, I've knocked up a very simple bash script (if I were to be bold enough to call it that) that you can steal from me.

#!/bin/bash 
lsmod | grep -e "ir_*" -e "dvb_*" -e "lirc_*" | awk '{ print $1 }' | tr '\n' ' ' | awk '{ print "sudo modprobe -r " $0 }' | sh
This will unload all modules relating to DVB and infra-red devices immediately. I wouldn't advise using this if you have other DVB or infra-red devices present on your systems that you need to keep functional, as it WILL disable them.

Once the modules are unloaded your system will be in the same state it was before you compiled the DKMS kernel modules.  You're now ready to start tinkering with the extended functionality of the device, which is way more fun than the DVB-T stuff.  My next post will tackle how to get GNURadio up and running, to the point where you can tune into FM radio stations.

Thanks for reading,

Chris

2 comments:

  1. looking forward to the sequel! :)

    ReplyDelete
  2. Me too :) Thank you very much for the PPA repo.
    This has helped me to get the DVB-T usb stick working.

    ReplyDelete