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steve-m / fl2k-examples

Example flowgraphs for osmo-fl2k
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How to upstream #10

Open tkalfaoglu opened 6 months ago

tkalfaoglu commented 6 months ago

In the readme there is a very short line about: "Then upsample them with the GNU Radio flowgraph. It's important to set the ppm variable with the value of your dongle, see the main README.md for details." I already established my ppm using fl2k_test, but how do I configure the Gnu Radio and upsample the generated data?

ericek111 commented 6 months ago

You can use an Interpolating FIR filter: https://wiki.gnuradio.org/index.php/Sample_Rate_Change

or, if you don't mind the nasty signal, just a simple repeat block will do.

tkalfaoglu commented 6 months ago

My aim was to simulate the GPS signal so that my brain-dead car navigator can be slowly brought back from where it thinks it's at :) After a factory reset, car's tomtom navigator thinks its 500km away from here and won't find new sattelites to understand its location. So I was hoping to use this system to "ease the navigator" back home slowly. I'll try the FIR filter method. I'm very new at this. I got the VGA dongle however! Many thanks!

tkalfaoglu commented 6 months ago

What should I set the filter parameters at? I see the input at 32 kHz and output at 128 kHz. Are those good values for GPS simulation?