fobos-sdr

RigExpert Fobos SDR -- a USB wideband receive-only SDR

Vendor: RigExpert

Status: untested — catalogued from documented sources, not yet proven here.

Not maintainer-verified: nobody on this project has run this hardware yet. The two facts are recorded separately on purpose (D-027) — a correct recipe and a tested device are different claims.

What it is

A USB software defined radio receiver from RigExpert, the Ukrainian maker of antenna analysers, with two families of firmware: the original, driven through libfobos, and an "agile" one with a fast frequency-scan mode, driven through libfobos-sdr-agile. Both libraries are receive-only: they set a frequency, gain and sample rate and read samples, and have no transmit call.

What you can do with it

General wideband listening through any program that speaks SoapySDR (SDR++, GQRX, CubicSDR, GNU Radio) or the vendor's own tools. RigExpert's published figures are not repeated: coverage, sensitivity and dynamic range are unmeasured here, and D-027 keeps "the identifier is right" and "it was run here" apart.

Setup

Install the libfobos and soapysdr-module-fobos units (the second pulls libfobos-sdr-agile, which it needs to build), run hammunition hardware apply to write the udev rule and add yourself to plugdev, and log out and back in. fobos_devinfo then lists boards on the original firmware and SoapySDRUtil --find="driver=fobos" should list the board. All three build into /usr/local on every target: no distribution packages them.

Known problems

Nothing was run against a board. A board on one firmware is invisible to the other library: the same USB identifier, a different bcdDevice, and no error. The agile library's own four example programs are not installed. The units are builds from upstream commits (two are untagged pins), not packages. Hardware revision 3 and earlier need particular firmware per upstream's versions.txt and README; this is not measured.

How it identifies itself

USB id	What	Confirmed	Node
16d0:132e	Fobos SDR on original or agile firmware, told apart only by bcdDevice	yes	libusb

What is not yet known

Not owned, so no descriptor has been read. Unknown: the manufacturer and product strings and whether the board reports a per-unit serial; whether the agile firmware's bcdDevice (0x0101) and the original's (0x0000) are the only two a unit shows; and every behaviour past enumeration. The firmware difference is visible only in bcdDevice, which this catalog's udev binding cannot match on, so one rule serves both. Closing it needs a Fobos attached from an owner, once on each firmware if they have both; scripts/identify-device.sh fobos-sdr does it read-only, no root.

Who can close it: nobody on this project owns one — an operator who does can close it with one lsusb (how).

Access and permissions

Group membership required: plugdev — added at install, applies at next login.

The generated udev rule provides a /dev/fobos-sdr symlink, mode 0660, group plugdev.

Firmware modes

• vendor_tool — tooling: libfobos The identifier does not change between firmware families; the descriptor's bcdDevice does (0x0000 original, 0x0101 agile), and libfobos and libfobos-sdr-agile each open only their own. fobos_fwloader from the libfobos unit writes firmware (its API is fobos_rx_write_firmware and fobos_rx_read_firmware, added in libfobos v.2.3.2). No separate bootloader or DFU identifier is recorded: none appears in either library's source, and whether one exists is part of the gap. Firmware writes were not run, and the firmware files are RigExpert's to download, not carried.

Software that makes it useful

libfobos, soapysdr-module-fobos

Upstream: https://rigexpert.com/