Pluto Spectrum Analyzer Uses Command Line

If you don’t care about shortwave frequencies, the PlutoSDR is a great deal. The device is supposed to be an evaluation board for Analog Device’s radio chips, but it does great as a software-defined radio that can receive and transmit and it even runs Linux internally. [SignalsEverywhere] shows how to use it as a spectrum analyzer that works from the command line in the video you can see below.

The software used is Retrogram. Despite the ASCII graphics, the program has many features. You can use simple keystrokes to change the center frequency, the sampling rate, the bandwidth, and more. You can run the software on a Linux host or compile a binary on the box or cross-compile using tools on the Raspberry Pi.

The Pluto connects via USB but looks like a network adapter. That means you can talk to it like a remote computer and software can run on the host computer or directly on the hardware which has an ARM processor (or two, if you hack it).

We noticed on the GitHub site that plans are in the works for generic device support like the ubiquitous RTLSDR dongles. We’d love to see someone pick up that work. There are also plans for mouse tuning, waterfall displays, and HTML output.

We’ve talked about the Pluto before. We’ve also seen [SignalsEverywhere] cover how to connect the Pluto Ethernet.

11 thoughts on “Pluto Spectrum Analyzer Uses Command Line

  1. So it’s a hardware SDR that’s actually an evaluation board, and the same company (maybe?) is making the software spectrum analyzer that works with the SDR board. The software presumably comes preinstalled on the SDR since it runs Linux, and currently doesn’t support any other SDRs. Did I parse this right?

    1. PlutoSDR is a learning module/experimentation board/reference design SDR from Analog. Retrogram-plutosdr is a third party command-line tool that runs on a Linux system, either a computer connected (via USB or Network) to the PlutoSDR or on the PlutoSDR itself. It seems to have started life as a hack of the Ettus UHD RX ASCII Art DFT code. The author of Retrogram originally seems to have written it for the PlutoSDR, and then created separate repos for RTL-SDR and SoapySDR interfaces.

  2. Before it was a gnuplot.

    img:https://www.rtl-sdr.com/wp-content/uploads/2019/01/gnuplot.png?ffccfa&ffccfa
    [img]https://www.rtl-sdr.com/wp-content/uploads/2019/01/gnuplot.png?ffccfa&ffccfa[/img]

    https://www.rtl-sdr.com/new-custom-firmware-for-the-plutosdr-with-several-linux-sdr-programs-pre-installed/

    Other scripts available on pluto

    – iio tools : iio-info, libiio 0.16
    – CW generator (python) (FG8OJ for CW processing code : https://github.com/fg8oj/cwkeyer)
    – SoapySDR + SoapyRemote 0.6 (Pothosware https://github.com/pothosware/SoapySDR)
    – LeanTRX ( + DATV TX scripts) (F4DAV and PABR team http://www.pabr.org/radio/leantrx/leantrx.en.html)
    – rpidatv.ts video sample to send video test stream directly from Pluto (courtesy F5OEO)
    – Python 2.7 (+numpy, also including iio and SoapySDR bindings)
    – rxtools : rx_sdr, rx_fm, rx_power ( Robert X. Seger https://github.com/rxseger/rx_tools)
    – LUAradio (Vanya Sergeev http://luaradio.io)
    – csdr ( + nmux) (Simonyi Károly College for Advanced Studies https://github.com/simonyiszk/csdr)
    – gnuplot + libpng
    – Busybox utilities : netcat, timeout, ntpd and more (at and timeout to perform scheduled tasks or end a task).
    – Retrogram (Peter Rakesh https://github.com/r4d10n/retrogram-plutosdr)
    – multimon-ng (Elias Önal https://github.com/EliasOenal/multimon-ng/)
    – OpenWebRX (András Retzler HA7ILM https://sdr.hu)
    – morfeus_tool

    * SoapySDR note : yes I know it’s not the last version, and I know why ;) WIP
    * Cross-compiled apps, except : leantrx
    * nmux note : nmux is a very good TCP listener, allowing several clients at the same time, keeping listener running after disconnection.

  3. “If you don’t care about shortwave frequencies…” You’ve lost me.
    I’m willing to have a second option for HF, but ignoring it completely is not an option.

    For example, the Icom 9700 covers VHF and higher, but the company also caters to HF enthusiasts with the model 7300.

    Now, if Analog were to create a learning module that covered shortwave, it would be another story.

    1. Well, it’s actually pretty easy to upconvert. There are common, fairly cheap upconverters available that let any sdr access lower frequencies.

      It takes some care with filtering and shielding, but the advantage is that you retain the broad simultaneous bandwidth most sdr solutions can provide. And, anything below VHF is noise-limited by the atmosphere rather than the converter, anyway.

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