8. Receiving Data - naubeeluck/OP-Cansat GitHub Wiki
SDR-RTL USB
This serves like a receiver/scanner of radio waves and can be used to see the strength of the signal from the transmitter using first without any antenna or just with the RG174's SMA connector connected and then using a Yagi to test its directivity and also strength of receiving signal.
Installing the SDR RTL software
The rtl-sdr dongle is useful to be able to ‘see’ the data packets. We’ll use a windows program called SDR# (sdr sharp). The ‘SDR# with Community Plugins’ version from Airspy is the version we need. Hereunder are some brief instructions about how to use it:
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Open SDRSharp.exe and set the "Source" drop down box to 'RTL-SDR USB'. This "Source" tab is on the lower left menu bar by default. On newer version of SDR# you may need to scroll down in the drop down box a little to find the RTL-SDR USB entry.
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Press the Play button (the right facing triangle in the top left of the program). Your RTL-SDR software radio should now be set up and ready to use! If everything has worked you should be able to start tuning to frequencies.
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Important! Don't forget to also adjust the RF gain settings by pressing the Configure button (looks like a cog/gear) up the top next to the Play button. By default the RF gain is set at zero. A gain of zero will probably receive nothing but very strong broadcast FM - increase the gain until you start seeing other signals.
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If it doesn't work, search for Zadig in the main Start menu. Open Zadiq and install drivers. Change contrast on left hand side menu towards middle to get a blue 'waterfall'
What should we see
If you tune the main tuning to 433MHz then give or take a few Hz the packets should be visible. They’ll come through once a second as flat lines. Just be aware that the Yagi might pick up all sorts of noise in the class room.
