RTL-SDR on the Raspberry PI
Intro:
A while ago I decided to venture into the world of Ham Radio. Under the advice of George I went out a purchased a cheap DVB USB dongle to use as a Software Defined Radio (SDR). I had thought about using it with the Raspberry Pi I bought a while ago.
How?
The software was pretty straight forward to setup, here are my instructions from a fresh install of the Raspbian distribution:
Only two additional packages are needed
apt-get install cmake libusb-1.0-0-dev
Download the latest Source
git clone git://git.osmocom.org/rtl-sdr.git
Actually do the building:
cd rtl-sdr/
mkdir build
cd build
cmake ../
make
sudo make install
sudo ldconfig
It Doesn’t work?
I found that on my particular PI (original 256MB Model B) that when the RTL-SDR stick was plugged directly into the USB ports on the PI I got the following repeated endlessly when I tried to run rtl_fm:
rtlsdr_demod_write_reg failed with -1 rtlsdr_demod_read_reg failed with -1
I first attempted to plug the RTL-SDR into a powered hub and instantly the issue went away. So I’m guessing everytime the rtl library reads or writes to the device it draws slightly too much power and the polyfuses trip. I haven’t yet bypassed them to find out if this is the case.