25 thoughts on “ADALM-Pluto GPS L1 simulator

  1. Hello Michael,
    I tried to run pluto-gps-sim multiple times. It seems that is running normally and increases the satellites in view which I can see them from an android app. However the signal never locks. I used the original project of Takuji Ebinuma with blade-rf and worked fine. Adalm-Pluto seems to have problem.. What should I do ? What do you suggest ?

    • Did you tried a higher attenuation setting? Maybe you simply overdrive the phones GPS LNA on short distance. There might be also a conflict in case your phone has several location service running and considers the GPS position as invalid.

  2. Looking for a direct link to download Zcat, seen a couple but they are different and am not sure which is a genuine working one.

    Also I see the software has been tested on Windows7, has anyone got it working on Win8/10

  3. Hi Michael,

    Thank you for your reply

    Using windows 8.1 64bit
    MVS 2015

    I get
    Unhandled exception at 0x7700D4E2(ntdll.dll) in pluto_gps-sim.exe
    0xC000007B %hs is either not designed to run on windows or it contains an error

    I see the DLL is used to covert 32bit to 64 Bit
    The WOW64 emulator runs in user mode.
    These DLLs, along with the 64-bit version of Ntdll.dll,

    Someone else had a similiar error in VS, and changing
    Configuration properties -> C/C++ -> Code Generation -> Run Time Library -> Multi-threaded Debug DLL (/MDd) worked for them

    But that did not work for me

  4. Additional Information
    If I select x64 then I see that
    #include iio.h
    #include ad9361.h
    have errors saying cant open file
    All the other Hex files are fine
    The two files do exist
    It is strange because if I right click on them () they appear in the editor, so VS must know where they are

    They also do not appear in the external dependicies list
    Also I can’t seem to see anything in the Add reference

    I’m used to VB.net so maybe I doing something wrong

  5. Hello Michael,
    I’m trying ‘gps sim sdr’ with pluto sdr, on ubuntu 16.04 using a virtual box. The gpssim.bin file generated, is typically upto 2gb and when I transmit it, I get error as:
    “could not create TX buffer.”

    Any suggestions you would make it to work ?

    • This error is not related to file size. In this case the TX sample buffer cannot be created, which is a memory access problem. Did you tried with sudo or as root?

  6. Sorry for the late reply.
    I did try with sudo, but the problem persists. Can you suggest any alternative for making it work?


    • I setup an Ubuntu 16.04 in VirtualBox. Can you provide the command line to start gps-sdr-sim? And which github project you are using?

  7. Hallo Michael,
    hast du mal den ADALM Pluto in Sachen ADSB Empfang mit den anderen Sachen (FA pro stick) verglichen? Wie ist da die Performance?
    Ich konnte ├╝ber einen Vergleich bisher im Netz nichts finden.

  8. Hi, i compiled the script and started the program. How to configure the Pluto for connectivity, dc block, …? What is the -B -A configuration on the frame to be entered for a reception on a GPS receiver.
    we put -B 5.0 -A -20.0


    • You don’t need to modify -B (bandwidth) and -A (attenuation). The default values are just fine. You may just set -A in case you need a higher output level.

  9. Hi Michael,

    I am trying GPS L1 simulator using pluto. I connected pluto tx to ublox GPS receiver rx through rf cable with 60db attenuator. When I see ucenter application I do not see ephemeris data received by gps receiver. I tried different combination of attenuator values but so far no luck.
    Is DC block required for the setup
    I tried the following repos

    please let me know what can be the reason or I am missing anything here.

      • Hi Michael,

        I found one issue , the issue was with Linux as guest operating system it was giving throughput of 1.5 MBps. then I tried Linux as host system now I see it reaches till 10 MBps.
        I tried https://github.com/osqzss/gps-sdr-sim this repository where we can generate .bin file from the trajectory of the positions and when I play using plutoplayer command I do see that ublox receiver is showing satellites in green color and it is getting fix in few seconds.

        But when I tried https://github.com/Mictronics/pluto-gps-sim repository means transmitting GPS l1 baseband data in runtime, the result was inconsistent ,most of the time receiver shows satellites in blue color on ucenter and never gets the fix

        And I modify for multiple position (changing position at every 0.1 sec) which never worked.

        I think the issue is mathematical equations for generating L1 baseband data every takes more time than it takes to write to the pluto device.so the receiver doesn’t see required satellites all the time ?

        • First I don’t understand the difference between host and guest Linux system. Second, the calculation efforts should be the same regardless of static or dynamic position. Because with a static position the (simulated) movement of satellites has to be calculated anyway. Third, my experience with ublox6 and ublox8 chipsets is getting a fix within 90 seconds after cold start and less than 30 seconds on warm start.
          Are you sure that your output signal level is low enough to be detected as “satellite signal”? Modern ublox chipsets include a (configurable) threshold for strong signals which then trigger the carrier jamming detection.

  10. Hello Tilak,
    May i ask how did you load gpssim.bin to pluto sdr? I am new on SDR so i don’t know how to transmit this file with pluto sdr.
    It says “plutoplayer -t gpssim.bin ” on github but i couldn’t figure out how to use this.
    Any help appriciated,

    • Hey FF,
      Did you ever figure this out? I’ve gotten to the point where I’m attempting to compile plutoplayer on Win 10, but I’m having some library path problems with LIBIIO (not compiling). Anyone have a Window’s executable link where we can download?

  11. Hi Michael,

    I have compiled pluto-gps-sim-win32 on Windows 10 and found that somehow it works but not quite.

    I connected TX of pluto to a scope and ran “pluto-gps-sim -e brdc.n -A -30.0”. I found that the waveform only lasted about 1s and then it went away. I stopped the command in powershell and re-ran it multiple times, and the result was repeatable.

    I wonder if you have seem such situation before, if so, what would be the resolution to it?

    Your help is appreciated.


  12. Hi Tony,

    Did you solve this problem? I have build https://github.com/osqzss/gps-sdr-sim. my bin is generated and i’m running for pluto SDR. (actually my board is adrv9361-z7035-fmc but this utilizes same transceiver, just more powerfull FPGA and more I/Os ). I ran pluto player and my TX started but it appears for 1s and disappears. It continues this behavior till complete bin file is transmitted. I checked the waveform on spectrum analyzer.

    For GPS test, I’m using GPS test android application. I’m getting nothing at my GPS receiver app

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