Receive PW Sat2 with GNURadio

Alternative options - GNURadio

NOTE: We've built a special super-easy to use application for receiving PW-Sat2 signal and uploading decoded frames to our cloud service. We encourage you to use this method. Here we present an alternative option - GNURadio Companion.

How to install GNURadio on Linux

1. Install PyBOMB: pip install pybombs

2. Install gnuradio via PyBOMBS: https://github.com/gnuradio/gnuradio#how-to-build-gnu-radio

3. Install kiss python module: pip install kiss

4. Clone PW-Sat2's gr-kiss repository: git clone https://github.com/PW-Sat2/gr-kiss.git

5. Build and install gr-kiss: cd gr-kiss && mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX=~/prefix/default .. && make -j3 && make install

6. Clone PW-Sat2's gr-gpredict-doppler repository: git clone https://github.com/PW-Sat2/gr-gpredict-doppler

7. Build and install gr-gpredict-doppler: cd gr-gpredict-doppler && mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX=~/prefix/default .. && make -j3 && make install

8. Run GNURadio by issuing in a teminal following commands: source ~/prefix/default/setup_env.sh gnuradio-companion

9. Clone GSControl repository - https://github.com/PW-Sat2/GSControl - it contains several GRC flow graphs to receive and demodulate signal:

• https://github.com/PW-Sat2/GSControl/tree/master/gnuradio/downlink/source - in this folder are located flow graphs for a few SDR receivers - basically they grab IQ data from the SDR, prepare signal (i.e. decimate to achieve correct sample rate, can receive data about Doppler frequency from GPredict etc.) and send IQ data via ZMQ protocol to demodulator (downlink.grc)
• https://github.com/PW-Sat2/GSControl/blob/master/gnuradio/downlink/downlink.grc - run this flow graph to demodulate signal from your radio - it takes IQ samples from signal source mentioned in previous bullet. Decoded frames are saved in downlink_frames file. Note: the file is replaced (i.e. wiped out) each time downlink flow graph is executed.

What can I do with downlink_frames file?

Option 1

It's basically the same file that is used by our desktop application. You can run the application from binary (as described in this wiki) or source (file main.py, using Python 2.7 interpreter). You should rename downlink_frames to file with .frames extension e.g. downlink_frames.frames to be seen by the application. Use "Load from file" button in "Cloud upload" tab in the application to send frames to our servers.

Option 2

Simple Python script to upload frames will be available soon.