I purchased an ezcap USB 2.0 DVB-T stick a while ago. Why what’s so special about a DVB-T receiver you say? Well device contains a Software Defined Radio (SDR), a Realtek RTL2832U, that is a radio interface that can be controlled using software. The drawback is that the this is only a receiver and that for some of you the radio spectrum might be to limited. But hey it’s cheap!
Requirements
- A RTL-SDR compatible receiver
- Linux based operating system (but there are also tools available for Microsoft Windows!)
Install the following dependencies:
$ sudo apt-get install libusb-1.0-0-dev git cmake
⇒ Detailed installation instructions can be found on Michael Hirsch blog.
However when I was testing the SDR usb stick I came across an error:
$ sudo ./rtl_test -t
Found 1 device(s):
0: Generic, RTL2832U, SN: 77771111153705700
Using device 0: Generic RTL2832U
Kernel driver is active, or device is claimed by second instance of librtlsdr.
In the first case, please either detach or blacklist the kernel module
(dvb_usb_rtl28xxu), or enable automatic detaching at compile time.
usb_claim_interface error -6
Failed to open rtlsdr device #0.
This can be solved by unloading the kernel module:
$ sudo modprobe -r dvb_usb_rtl28xxu
Now it should output something like this:
$ sudo ./rtl_test -t
Found 1 device(s):
0: Generic, RTL2832U, SN: 77771111153705700
Using device 0: Generic RTL2832U
Found Fitipower FC0013 tuner
Supported gain values (23): -9.9 -7.3 -6.5 -6.3 -6.0 -5.8 -5.4 5.8 6.1 6.3 6.5 6.7 6.8 7.0 7.1 17.9 18.1 18.2 18.4 18.6 18.8 19.1 19.7
Sampling at 2048000 S/s.
No E4000 tuner found, aborting.
Use Gqrx to get a nice graphical interface overview of the signals received:
$ sudo apt-get install gqrx-sdr
$ sudo gqrx
Now you can switch to a local FM radio station, for example 101.4 MHz. Spend some time getting used with it. Later I will try to do some more hacks with this, like processing the raw samples and applying some digital signal processing techniques to it. When you’re tired of hacking with it you can also use it for it’s original purpose, watching TV!