# LimeSDR-USB Transmit with gr-limesdr

**URL:** <https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929>\
**Category:** LimeSDR\
**Created:** [15 June 2018 16:51 UTC](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929 "2018-06-15T16:51:16Z")\
**Posts on this page:** 13\
**Page:** 1

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**Author:** ![yindra](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/yindra/32/1901_2.png) [@yindra](https://discourse.myriadrf.org/u/yindra)\
**Post date:** [15 June 2018 16:51 UTC](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929/1 "2018-06-15T16:51:16Z")

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I would like to transmit from the LimeSDR-USB using gr-limesdr and GNU Radio. I downloaded the new limesuite and gr-limesdr a few hours ago. Attached you will find the flow graph I used and the picture I got. I expected to see the two tones on the spectrum analyzer; I only see the IF frequency.

 ![2018-06-15-114611_1360x892_scrot](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/0/0c4f11d2bca38a71de08d3651ff01ca9475ed915.png)  
 ![20180615](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/a/a8ab9990497de8dad21873ec6a10952afc01bb9a.jpg)  
Why don’t I see two tones transmitted?

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**Author:** ![Zack](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/zack/32/89_2.png) [@Zack](https://discourse.myriadrf.org/u/Zack)\
**Post date:** [18 June 2018 08:50 UTC](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929/2 "2018-06-18T08:50:37Z")

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Hi @yindra,

Our guys came up with this gr file: [Microsoft OneDrive](https://1drv.ms/u/s!AsTX3WCH_RLChyjhvf-JtfOpLT9I)

The result is as follows:

 ![1529305797777](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/e/e847fffef555593013e4d64e4bc8ef80144ce3f5.JPEG)

 ![1529305807827](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/c/c76e9cfe45711fb19f5b207c0f49d2a44a2a51f6.JPEG)

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**Author:** ![yindra](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/yindra/32/1901_2.png) [@yindra](https://discourse.myriadrf.org/u/yindra)\
**Post date:** [18 June 2018 14:22 UTC](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929/3 "2018-06-18T14:22:09Z")

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I ran the file you sent and here is my result:

 ![20180618](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/2/2d760d5d99aa060b6c1e5c5b04c61d1f91bc350a.jpg)

I ran LimeUtil --update and got the same result with image 18.06/LimeSDR-USB\_HW\_1.4\_r2.17.rbf  
What firmware version are you running? do you think my LimeSDR-USB might be broken?

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**Author:** ![yindra](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/yindra/32/1901_2.png) [@yindra](https://discourse.myriadrf.org/u/yindra)\
**Post date:** [19 June 2018 20:55 UTC](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929/5 "2018-06-19T20:55:03Z")

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I tried one more thing: Using different revisions of LimeSuite, I transmitted the same data file with [limesdr\_toolbox](https://github.com/emvivre/limesdr_toolbox).

First I created the file (2e6 sps) with Gnu Radio and a USRP, so this is my expected output:

 ![UHD_Transmit](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/4/49d941f5fb1d317fa49e6c64419ac8a5257b8b4d.jpg)

Second, I reverted LimeSuite to version 17c3e05 which is firmware version 18.04 and I sent the data with limesdr\_send application from limesdr\_toolbox and I got this:

 ![04_Limesuite 17c3e05](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/2/2e76422518b8876fb87e52ce78c92baa9344ec72.jpg)  
But, in limesdr\_send, LMS\_SendStream returned the error “L”. I don’t know what “L” means.

Finally, I updated LimeSuite to version 739bd85 which is firmware version 18.06 and I sent the data with limesdr\_send application from limesdr\_toolbox and I got this:

 ![06_Limesuite 739bd85](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/c/c5a7798c33506c36e4f585e47cd67067e58554bb.jpg)  
NOTE: this is only the IF. The limesdr\_send application never terminated. I expected limsdr\_send to terminate after about a minute because that’s how long I recorded to create the data file. I have a feeling that the data was never transmitted to the limesdr.

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**Author:** ![Zack](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/zack/32/89_2.png) [@Zack](https://discourse.myriadrf.org/u/Zack)\
**Post date:** [20 June 2018 07:17 UTC](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929/6 "2018-06-20T07:17:50Z")

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Hi @yindra,

I would suggest to use the latest [LimeSuiteGUI](http://wiki.myriadrf.org/LimeSDR-USB#Software) (pre-compiled Windows version preferred) and perform a [Quick Test](http://wiki.myriadrf.org/LimeSDR-USB_Quick_Test) procedure. Update the gateware to the latest one using LimeSuiteGUI.

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**Author:** ![Cornie](https://avatars.discourse-cdn.com/v4/letter/c/7c8e57/32.png) [@Cornie](https://discourse.myriadrf.org/u/Cornie)\
**Post date:** [20 June 2018 16:16 UTC](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929/7 "2018-06-20T16:16:31Z")

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For me the file worked with LimeSDR\_USB and LimeSDR\_miniFor some freq the TX cal failed until I increased TX gain. (Tx Calibration: MCU error 5 (Loopback signal weak: not connected/insufficient gain?)

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**Author:** ![yindra](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/yindra/32/1901_2.png) [@yindra](https://discourse.myriadrf.org/u/yindra)\
**Post date:** [20 June 2018 16:17 UTC](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929/8 "2018-06-20T16:17:07Z")

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Here is the Quick Test result:

 ![image](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/6/6bed2c9ccf74386b06f21ef99f701c2dd07fbb9a.png)

Here is the RX test signal:

 ![image](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/3/3bbde0dd46a538e57343aef0ecb9c7d782dc3e89.png)

Here is the TX carrier signal:

 ![20180620_txCarrierSignal](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/b/b42d6887b7693680e4b83e3fc996148b1c42469b.jpg)

Here is the TX test signal:

 ![20180620_txTestSignal](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/0/0bfec4e4e8fd22cea1cda491baf71b203df8d817.jpg)

I got the same results when I loaded the 18.06 firmware with Modules-\>Programming (it then downloaded the 18.06 firmware and installed it) with LimeSuiteGUI\_20180613\_1cb1723.exe

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<div class="post-metadata">

**Author:** ![yindra](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/yindra/32/1901_2.png) [@yindra](https://discourse.myriadrf.org/u/yindra)\
**Post date:** [20 June 2018 16:19 UTC](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929/9 "2018-06-20T16:19:11Z")

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Yes, I have seen this error in Gnu Radio occastionally, but, in post about limesdr\_toolbox tests, the only error I got was “L”.

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<div class="post-metadata">

**Author:** ![Cornie](https://avatars.discourse-cdn.com/v4/letter/c/7c8e57/32.png) [@Cornie](https://discourse.myriadrf.org/u/Cornie)\
**Post date:** [20 June 2018 16:21 UTC](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929/10 "2018-06-20T16:21:18Z")

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Is there a reason for switching off the analog filter? I think the analog filter would reduce aliasing.

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**Author:** ![KarlL](https://avatars.discourse-cdn.com/v4/letter/k/dfb087/32.png) [@KarlL](https://discourse.myriadrf.org/u/KarlL)\
**Post date:** [21 June 2018 06:07 UTC](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929/11 "2018-06-21T06:07:09Z")

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I’m also seeing this for reception:

`e[1me[31m[ERROR] Rx calibration: MCU error 5 (Loopback signal weak: not connected/insufficient gain?)e[0m`

@Zack: is this a real error (for Tx and Rx) or more of a warning? Things seem to be working well on the Rx part even with this message.

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**Author:** ![ricardas](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/ricardas/32/86_2.png) [@ricardas](https://discourse.myriadrf.org/u/ricardas)\
**Post date:** [21 June 2018 08:16 UTC](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929/12 "2018-06-21T08:16:27Z")

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If gain is insufficient, the calibration is terminated and has no effect.

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<div class="post-metadata">

**Author:** ![Zack](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/zack/32/89_2.png) [@Zack](https://discourse.myriadrf.org/u/Zack)\
**Post date:** [21 June 2018 08:25 UTC](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929/13 "2018-06-21T08:25:26Z")

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Hello @yindra,

As far as I see, the board is working correctly. So, it looks like the problem is in software (used in GNU Radio chain) version mismatch.

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<div class="post-metadata">

**Author:** ![yindra](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/yindra/32/1901_2.png) [@yindra](https://discourse.myriadrf.org/u/yindra)\
**Post date:** [21 June 2018 18:11 UTC](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929/14 "2018-06-21T18:11:27Z")

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@Zack  
I still get the same result with new software, and on a different computer.

So here are the versions of software that I’m using

1. I’m on a Intel Core i5 running Windows 7 Professional (64 bit)  
a) I uninstalled Pothos and GNU Radio and rebooted.  
b) The windows driver hasn’t changed in git, so I didn’t re-install that.  
c) I programmed the 18.06 firmware yesterday with this version of LimeSutie: LimeSuiteGUI\_20180613\_1cb1723.exe
2. I installed GNU Radio (gnuradio\_3.7.12\_win64.msi) from here [http://www.gcndevelopment.com/gnuradio/downloads.htm](http://www.gcndevelopment.com/gnuradio/downloads.htm)
3. I installed gr-limesdr from here: [GitHub - myriadrf/gr-limesdr: gr-limesdr Plugin for GNURadio](https://github.com/myriadrf/gr-limesdr)
4. I started GNU Radio and ran [two\_tone.grc](https://onedrive.live.com/?authkey=%21AOG9_4m186ktP0g&cid=C212FD8760DDD7C4&id=C212FD8760DDD7C4%21936&parId=C212FD8760DDD7C4%21935&o=OneUp)
5. I get the same picture as I did on my Ubuntu computer:  
 ![20180621_windows](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/e/e7f258dac77f95c752791a425ec86d0b1e620a64.jpg)

EDIT: I removed the USB 2.0 extension cable I was using and now the picture looks correct:

 ![20180621_windows_USB3](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/d/d1803aada3509ce0d5585795b265bc0ce630085b.jpg)

It was not just the cable because plugging the LimeSDR-USB directly into the USB 2.0 port gave me the same picture as the pictures with the USB 2.0 extension cable. All pictures, except the one where I said that I removed the USB 2.0 extension cable, were using the cable; this cable was used for taking the self test pictures in my previous posts.