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Does this work with RTL-SDR device?

Open MatejKovacic opened this issue 3 years ago • 5 comments

Hi, does this work with RTL-SDR device?

MatejKovacic avatar Nov 09 '21 08:11 MatejKovacic

Hi. I've never tried it, but my simulations with less than 5 MSps obtain a too blurred image. You should at least work at 10 MSps.

git-artes avatar Nov 09 '21 11:11 git-artes

I would like to try it, but don't know how. I mean, I have compiled the software nder Ubuntu 20.04.3, I run gnuradio-companion and open one of the examples file (manual_tempest_example), and there is UHD USRP Source block, which is grayed out...

Any help on this?

MatejKovacic avatar Nov 09 '21 11:11 MatejKovacic

Have you tried using the recordings first? Or the simulated flowgraph? You should try those first, in order to get a basic understanding of how the system works. Then, you may replace the hardware block with the rtl-sdr source and see if it works (although, again, I don't think you'll get anything "readable").

git-artes avatar Nov 10 '21 12:11 git-artes

Since the rtl-sdr has only 2.5ish MSps this may be too blurry for full monitor images, but shouldn't in theory this work for slower LCD screens that are available on all kinds of devices? I specifically found this project while searching for this with rtl-sdr support, and would love to try it out on real hardware but the question also is for me how to find the frequency to tune things to...

PlasmaHH avatar Apr 19 '22 12:04 PlasmaHH

The frequency that you should tune to is the pixel rate (or any harmonic): total_heighttotal_widthrefresh_rate. If pixels are coded (as in HDMI), you may also try tuning to the bit rate: the same as before, times the number of bits per pixel. To understand the not-so-really complicated math behind this you may see the talk I gave on GRCon 2021: https://youtu.be/k_vsFspGpAA

git-artes avatar Apr 19 '22 16:04 git-artes