This step-by-step instruction is tested on the Raspberry Pi with the raspbian distribution and a Terratec Cinergy TStick RC with E4000 tuner and an ezcap 2.0 DVB-T dongle with R820T tuner. I recommend a USB hub with seperate power supply that supports more than 100mA on one USB port. The voltage at the raspbery has to be stable and not below 5.0 V, if not you can run into sync errors with the stick.
It is recommended to update to version 1.0.0 or higher of pymultimonaprs, because if the connection to the internet is interrupted there will be no packets routed to the APRS-IS network anymore. Also the startscript and setup was updated.
Preparing the Raspberry Pi
sudo apt-get update sudo apt-get upgrade sudo raspi-config mkdir ~/src
Avoid the Raspberry to load a kernel module
Edit /etc/modprobe.d/raspi-blacklist.conf file and add the following lines
blacklist dvb_usb_rtl28xxu blacklist dvb_usb_v2 blacklist rtl_2830 blacklist rtl_2832 blacklist r820t
Then reboot the Raspberry or enter ’sudo rmmod dvb_usb_rtl28xxu‘
Installation of driver for the DVB-T dongle
cd ~/src sudo apt-get install git build-essential cmake libusb-1.0-0-dev git clone git://git.osmocom.org/rtl-sdr.git cd rtl-sdr mkdir build cd build cmake ../ -DDETACH_KERNEL_DRIVER=ON -DINSTALL_UDEV_RULES=ON make sudo make install sudo ldconfig
Test the rtl dongle and determine possible gain settings
rtl_test
Based on your antenna setup you have to choose a different gain, so that your signal is strong enough but not overloaded. I suggest to start rtl_tcp on the console and start SDRsharp, SDR-Radio, etc. on another computer and play with the gain settings.
Installation of multimonNG decoder
cd ~/src sudo apt-get install qt4-qmake libpulse-dev libx11-dev patch pulseaudio git clone https://github.com/EliasOenal/multimonNG.git cd multimonNG mkdir build cd build qmake-qt4 ../multimon-ng.pro make sudo make install
Installation of kalibrate tool
cd ~/src sudo apt-get install libtool autoconf automake libfftw3-dev git clone https://github.com/asdil12/kalibrate-rtl.git cd kalibrate-rtl git checkout arm_memory ./bootstrap ./configure make sudo make install
Example of calibrating your DVB-T dongle with E4000 chip (remember PPM for later)
kal -s GSM900 kal -c 36
Channel 36 was the strongest in my region, yours can be different.
With the new R820T(2) Chip the kalibrate tool will give us often the wrong PPM value. You can use the command rtl_test -p instead, which will show you the right PPM value after some minutes runtime.
Installation of APRS IGate software
cd ~/src sudo apt-get install python2.7 python-pkg-resources git clone https://github.com/asdil12/pymultimonaprs.git cd pymultimonaprs sudo python2 setup.py install
Prepare the startscript
sudo cp pymultimonaprs.init /etc/init.d/pymultimonaprs sudo chmod +x /etc/init.d/pymultimonaprs sudo systemctl enable pymultimonaprs
Generate APRS-IS password for own CALL
cd ~/src/pymultimonaprs ./keygen.py CALLSIGN Key for CALLSIGN: 31983
Please only use your CALLSIGN without the SSID.
Change configuration file (Call, password, position, gain, ppm, etc.)
sudo nano /etc/pymultimonaprs.json
Do not use leading zeros in front of lat and lon parameters.
To test if all is configured well and works fine enter the following (Strg+C cancels)
rtl_fm -f 144800000 -s 22050 -p 18 -g 42.0 - | multimon-ng -a AFSK1200 -A -t raw -
The 18 behind the -p option is my PPM and the 42.0 behind the -g option is one of the available gain settings of my stick
Start pymultimonaprs
sudo /etc/init.d/pymultimonaprs start
Have fun.
AddOn: Catch the ISS APRS Frames too
Edit pymultimonaprs/multimon.py and change line 32-35 to
proc_src = subprocess.Popen(
['rtl_fm', '-f', str(int(self.config['rtl']['freq'] * 1e6)), '-f', '145825000', '-s', '22050',
'-p', str(self.config['rtl']['ppm']), '-g', str(self.config['rtl']['gain']), '-l', '10', '-'],
stdout=subprocess.PIPE, stderr=open('/dev/null')
If you add more than one -f option, then the -l option is necessary (squelch).
After that build and install the code again.
sudo python setup.py build sudo python setup.py install sudo /etc/init.d/pymultimonaprs stop sudo /etc/init.d/pymultimonaprs start
