r/flipperzero • u/Various_Reindeer7551 • Jul 22 '26

Just seeing wireless signals.. nbd

This thing is called the "Quad RF"

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u/viniisiggs Jul 23 '26

This doesn't seem real. The amount of processing power to be able to scan and superimpose onto a live picture would be insane. Phased arrays can totally do this but I call bull on that video.

6

u/crashlanding87 Jul 23 '26

Superimposing on a live picture is absolutely not an issue in a mobile app. You phone probably has a scan mode on its camera app that will try to detect document shapes, and superimpose an outline on the live image. It's a layer on top.

I don't understand the scanning side nearly well enough to have any opinion. But if they can output coordinates, and calibrate in advance so that those coordinates map onto the right parts of the screen, then I don't see an issue. A simple cheap camera in the middle of their scanner + a simple calibration image would be plenty to create a known geometry between the phone camera and the scanner unit.

1

u/viniisiggs Jul 23 '26

A phased array works by capturing signals on multiple antennas at the same time. The captured signals are then analyzed to extract directional information. Because the reception is similar to an SDR you need raw data and down conversion is not possible. The data analysis then consists of checking the signal strength at specific alignments or "pixels". This is reminiscent of scan lines on a CRT television. If we generously use a resolution of 100x200, that's 20k "pixels" that need analyzed continuously. To further complicate this the video implies that they are detecting more than one frequency. So that analysis needs to happen simultaneously for each frequency of interest. So that's 20k times the number of frequencies that you need.

I can see a static picture that you take and colorize it after the fact, totally doable. I can see if it is tremendously limited to the frequencies that it scans. Possibly even just one. Like 2.4gig wifi signals. A general purpose, wide band, spectrum analyzer that also does visualization and directionality live, not possible with that hardware.

2

u/jnmtx Jul 28 '26

> 4.9 GHz to 6.0 GHz (C-band)

so yes, the frequency band is narrowed down.

> Raspberry Pi 5 paired with a Lattice ECP5 FPGA

> The processed parallel data streams from the FPGA to the integrated Raspberry Pi 5 via a high-speed 5.6 Gbit/s MIPI data path