LimeSDR ExtIO Plugin for HDSDR

I am happy to share LimeSDR ExtIO Plugin for HDSDR. Check the Wiki page for installation instructions, links and documentation:

LimeSDR-USB and LimeSDR-Mini boards supported.

It is based on @jocover ExtIO plugin hence a big thank you!

Comments and notes are welcome! Thank you all for your support!


@Zack - Zack,

While this is really cool and most likely more reliable than past ExtIO efforts with the Lime, I’m not seeing any provisions for transmit support with this, and HDSDR supports transmit capability. Will there be a version out anytime soon that will support transmit as well? Let us all know - thanks,

73 de Marty, KN0CK


I am sooooo thankful for you coders, that put your efforts forward to us all.
I just slap lots of junk together to take advantge of it.



Hello @Zack and thank you for this new addition.
I think the diagram (that I guess comes from fig. 3 of the datasheet, page 4) has wrong symbols for the RX LowPassFilter:

…and should be like this:


Hi @martywittrock,

Regarding transmit capability - yes, we are planing it, just it is not going to happen in few days.

@mariocannistra - thank you for your sharp eye! Will fix it.


What causes the “Unknown error” dialog?


Never mind, I just had to update my gateware in LimeSuite. I bought the board with GW 1.22 and apparently this needs 1.24. Now HDSDR works with EXTIO.

Hi Zack

Just been using your ExtIO with HDSDR and it receives fine on my old Windows7 laptop. I sorted out the need for a second sound card (USB) for a mic input, but then HDSDR reports that TX is not supported. How’s progress going in this since April?

My LimeSDR-Mini connected to USB3, (It working with CubicSDR - but not bellow 30MHz). GW is 1.26. OS is Win10.
If I starting HDSDR with LimeSDR-Mini and select ExtIO_LimeSDR_1.05.dll from list, I get errormessage: SetFrequencySXR(30MHz) - cannot deliver frequency.


@tony1tf HDSDR has released the new 2.8 beta version, though after looking at it I can tell you that TX isn’t coming soon.

@om3bc I could not reproduce your problem. Try to open HDSDR without selecting any dll, change the LO frequency to something higher than 28 (100 MHz should be fine), restart HDSDR this time selecting the ExtIO_LimeSDR_1.05.dll.

It is an logic step. I tried it as first step. I have set LO to 125MHz. Errorcode is some.


@om3bc Can you give this dll a try? And try to do LimeQuickTest, maybe your board isn’t working properly.

I tried HDSDR 2.80 Beta11 and ExtIO_LimeSDR_test on PC with W7 64bit and W10 32bit. Not working. See errorcodes.
LimeQuickTest - Board Test PASSED OK on W10-32bit, but errorocode on W7-64bit.
It is not problem with LimeSDR.
Text in Win7-64bit is: %1 is not valid application for Win32

06 AM

Same problem. Just cannot use Lime mini with HDSDR. Sad.

On Windows 7, have you installed the correct redistributable package?
And I might have made a mistake in the first dll I’ve given you. Could you try this one on W10?

@om3bc - Joe,

Unfortunately only the LimeSDR works with HDSDR. The Lime-Mini’s driver set is not the same as the LimeSDR and doesn’t support OsmoSDR/osmocomm drivers yet which are integral to the HDSDR app (compatibility). Once an osmocomm DLL is written for the FTDI driver then you’re good-to-go. I have no ETA on when that be happening because the developers aren’t focused on that from what I can see right now.

73 de Marty, KN0CK

W10-32bit ExtIO_LimeSDR_Tv2:
50 PM:
51 PM


After install of VC, LimeQuickTest and HDSDR on W7-64bit with ExtIO_LimeSDR_Tv2 working, but only above 30 MHz.


@om3bc - Joe,

It’s likely that the ExtIO_LimeSDR_Tv2.DLL does not have the ‘HF Tricks’ installed that call for the NCO to be loaded with a subtraction to make the LO fall below and tune into the HF Bands. Established programs like SDRAngel for Windows 10 are capable of tuning to the HF Band for receive and transmit. If you review how Edouard performed the tuning, the same thing would have to be applied to the ExIO_LimeSDR_Tv2 code to make it tune below 30 MHz…Clear down to 100 kHz from what I’ve observed. I’ve successfully tuned the V1.4 LimeSDR I have into the lower AM Broadcast Band all the way down to 600 kHz and heard my local AM station, WMT-AM in Cedar Rapids, Iowa. So it’s entirely possible to do - the DLL just doesn’t have the hooks in there to perform that right now for it to work on HDSDR. It’s strange, but the earlier versions of the ExtIO_LimeSDR.DLL could tune the lower HF bands, so I’m wondering how they lost the recipe for that…

73 de Marty, KN0CK

Not true. Extio LimeSDR plugin supports LimeSDR-USB as well as LimeSDR-Mini boards.

Not true. Extio LimeSDR plugin is based on LimeSuite API which implements NCO tricks for frequencies bellow 30MHz.

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