/r/GNURadio
A subreddit dedicated to the GNU Radio project and any software-define radio (SDR) related content (including USRP, etc. news).
Interesting technical papers or articles are particularly welcome!
Recommended subreddits
/r/GNURadio
5,788 Subscribers
Benchmark module for over-the-air wireless communication
a flexible and easy-to-use benchmark module that can evaluate the over-the-air performance of various software-defined radio (SDR)-based communication systems in GNU Radio.
This module can provide the system performance metrics of packet transmission in realistic communication channels including packet error rate (PER), packet loss rate (PLR), signal-to-noise ratio (SNR), latency, and throughput. It can be easily added and used in the GUI GRC flowgraph. I have tested this module outdoors with over-the-air transmission using USRP N210 and DQPSK, GMSK, GFSK, etc. This tool provides a flexible benchmark method that works with various communication systems that use different communication protocols, signal-processing techniques, and SDR hardware in GNU Radio. This is because this benchmark module depends mainly on the received radio signal and data packets, unlike other benchmark tools which are limited by specific SDR hardware and communication techniques. We believe that this tool will provide great help to the GNU Radio community in evaluating the performance of the developed communication testbeds and prototypes in GNU Radio.
The module and its instructions is uploaded to GitHub:
20:09 UTC
waterfall over network
Disclaimer: this might be a recurring question, apologies if so, I've searched and couldn't find.
I want to view SDR waterfall over network. I've searched ready solutions (like `sdrpp --server` or OpenWebRX) but none of them do quite what I need. I thought it should be possible to build something simple enough with GNU Radio? Like source -> fft -> tcp-sink ~ tcp-source -> waterfall display. And some XMLRPC back to adjust frequency. Would this work? What would I take as the waterfall for that? Has anyone done this before?
14:19 UTC
Automatic spectrum sweep in gnu radio
Hello.
Has anyone managed to make an automatic spectrum sweep in gnu radio. In detail, i want to to change automatically a variable from 0 Hz to 1 GHz (with the name of frequency) with a step of that of the sample rate 2.4 MHz, that i will put in my RTL SDR source block in the center frequency postition, so to change the center frequency that my RTL SDR tune in and in extenstion to change the spectrum analyzer automatically. I have implemented this in 3 different ways with python code and all three ways are working when i use the (changing with python code) variable only in the RTL SDR source block. But i want to see in real time the changing spectrum, so i have to connect my RTL SDR source block with a QT GUI frequency sink and for seeing the changing specrum i have to put in its center frequency position my (changable) variable. But when i do this, after a few seconds and sweeps the system is cracking and i have the following message: QCoreApplication::sendPostedEvents: Cannot send posted events for objects in another thread.
So as i understand, there is a problem with my variable that is changing through my python code and it can not be send properly in frequency sink. Maybe i have to change the frequency variable as more global from the code of the flowgraph, so it changes properly. I dont know. Can anyone help me?
12:43 UTC
Plotting Data on a Graph and more
Hi, I have three questions if anyone can help out. One, I am trying to figure out how to use a gui to display and plot the power of a signal in dB(y axis) by time(x axis). With the bottom row, I was able to find the dB and output the number, but I am having trouble putting it on a graph(middle row). I have tried using a gui time sink but that wasn't what I wanted because it was basically displaying a flat line where the power would be at in dB.
Two, how do I display the frequency of the signal? I know it is supposed to be 2.4GHz, but when I look at the QT GUI sink, it is centered at zero where x is the frequency axis and y is dB. I have tried checking the Display RF Frequencies checkbox on the gui but I don't see anything display.
Three, how would I be able to log the graph that I am trying to plot?
In the photos I have, the first diagram that is run outputs the second photo. The third photo is what I am working with right now, which doesnt work.
Any help would be appreciated. Thanks
01:05 UTC
GNU Radio soft
Hello everyone! I have 2 programs in GNU Radio for my bachelor degree, one for receiving and one for transmitting RF. First is a frequency scanner and the other program is a noise (in db) transmitter based on the frequency that I scanned. And I have a question. Considering that I have 2 hackRFs, one used for transmitting and one for receiving (connected on my laptop), is it possible to make a program where I can use both of them at once. For example I fly a cheap drone (20$) over the antenna, it detects the frequency, and based on this, it automatically modifies the frequency on my transmitting program to send the noise exactly on the frequency scanned. For now I can do it only manually. First I scan the frequency and then I modifiy it in my transmitter program. Is there any possibility to do it automatically?
09:16 UTC
When to filter?
I have a question - been learning DSP stuff on my own in service of SDR. I want to write an AFSK decoder, and so I got a GnuRadio example for the SSB piece here: https://jeremyclark.ca/wp/telecom/rtl-sdr-for-ssb-on-gnu-radio/ and find i get the output I am expecting. I have read in various places that we should do a low-pass filter first, and then resample to avoid aliasing.
So I swap those two blocks and adjust the sample rates, and I get garbage output. However! When I replace the 8000000 sample rate in the LPF block with 48000, it works! I am curious then why when I filter and downsample in the LPF block to a rate of 48000 Hz, and then downsample again by a factor of 8k, I get a good signal?
You can see my grc graphs below. fig 1 is from the website, implemented as described there. fig 2 flips the filter and resample to filter first, then resample (note the filter sample rate). fig 3 is the same config but with the lower sample rate. Why does 3 work but not 2??
img 1: as described on the website and fully functional
img 2: swap filter and resample to avoid aliasing (adjust the params as well to 8MSPS in filter)
img 3: same as 2, but LPF sample rate is now 48000?? And this works??
01:30 UTC
What OS you run GNRTadio on?
What OS are you running GNU radio on? Which specific flavor of LINUX? I use Debian 12 but am running into issues. What transmitter do you use? I use HackRF One.
03:14 UTC
HACKRF one to fax
Hello everybody, I must admit im by no mean an expert nor an amateur. I,m kind off a noob.
Anyway, I study art and found back my hackrf one from my hacking teenage rebellion. I'm experimenting with fax since few weeks and i cant retein myself to ask this:
Can we send some fax data to a fax using a hackrf one? Can we record some radio ""sounds" then transmit it to the fax and let it interpret it since i know we cant dual with an hackrf one?
How can we play in an artistic way with hackrf one other than with fax? Do yo guys tried some things here and there?
Thx for reading really and if u help me i thx u 10x times more!!!!
18:57 UTC
USRP underruns
Hi all. I' ve been following the packet communication tutorial, https://wiki.gnuradio.org/index.php/Packet_Communications, and works fine. I decided to use this flowgraph with my actual hardware, a b210 as transmitter and b200 mini as receiver.
This is thre resulting flowgraph i have on the transmitter side, where my problems begin:
And this is what i got every time I execute it:
I dont understand why is this happening, because If I understand it correctly, fractional resampler is upsampling the signal, from 48kto 768K(48K/0.0625), so should have been enough samples for the usrp sink.
Thank so much in advance!
12:36 UTC
GFSK File transmission
I'm a student and am interested in how wireless file transfer works. I use some SDRs to Transmit and receive signals.
Here comes my problem:
I cannot find good resources on how to build a file transmission flow-graph in Gnu radio. I would like the modulation to be GFSK to ensure a stable link (despite slower data rate). Does anyone know how to setup an test a file transmission where i just send a simple txt file or similar to another computer with it's own sdr to receive the signal?
Help would be appreciated :)
10:52 UTC
Need to debug GNU Radio flowgraph
Need help with GNU Radio please:
My setup: Laptop running Debian OS 12 (Linux). Using HackRF One. Using latest GNU Radio package v3.10.5.1. I have set up a simple flowgraph of an audio source -> NBFM Transmit -> Multiply Constant -> Soapy HackRF Sink.
Steps to reproduce: I press play and a terminal window pops up with text output, then crashes. I get errors in the console window on the bottom left hand corner.
Why does my terminal window crash? Is it possible to pipe the output of that terminal window that pops up to a flat file?
23:45 UTC
[Help!] Turning My Bed into a Smart(er) Device: A DIY Project
Hi and thanks for reading this:
I’m interested in learning how to replicate the RF signals of the remote controls in my apartment. I’ve long been a SmartHome enthusiast and have the majority of my home automated (blinds, lights, vacuum, etc.). I have the week off work, and decided it would be fun to take up a pet project I’m interested in learning my SHA CERLIN bed’s 2.4ghz RF Controller remote signals, replicating them from a Raspberry Pi with an RF transceiver (and wifi- compatability and the GoSmart API) from my "Go Smart" app on my phone.
I have no experience using an Arduino, but I do own one (with its base accessories relatively missing). I would prefer to work through my Pi.
I’m interested in somehow capturing, reading, and demodulating my remote’s command. Injecting them into some software, and transmitting them from my Raspberry Pi using an RF Transceiver to control the bed. I’d like to solely dedicate the wifi enabled controller to controlling my bed, and hide it in my desk, plugged into the wall.
I’ve never even attempted something like this before, but figure this could be a fun (and seemingly easy / low-stakes) place to start. It seems like my idea is feasible too! Unless I’m missing something!
So far here’s what I’ve gathered:
- My Bed's remote control (manuals, test reports, and label info)
- A nRF24LU1 2.4GHz 1mW USB Wireless Data Transceiver Module (doesn’t appear to have an antenna?)
- A Raspberry Pi Zero 2
- An Arduino UNO
- An RTL-SDR Blog V4 R828D RTL2832U 1PPM TCXO HF Bias Tee SMA Software Defined Radio with Dipole Antenna Kit from Amazon
I'm told my remote is a bit more complicated because it uses 2.44ghz frequencies which are the common frequencies used for BLE and Wifi. I assume I will need to use my SDR to demodulate the remote control codes (which apparently are in GFSK?) in order to reproduce them. I used GNU Radio to try and achieve this, and really don't have a strong understanding of what I should be looking for or what settings I should be using.
I’m really looking for the most plug and play option available–– but also open to learning something new! If that’s the case, I want to make sure I’m buying the right things for the project.
Coding will be a challenge for me, but I have a lot of software engineer friends who may be able to help!
Looking for any advice, points in the right direction, links, youtube videos, resources etc!
[Edit 1]
Seeing faint waves around here in SDR#. Any way to improve this? How do I export this for use beyond SDR# so that I can demodulate it and replicate it from my nRF24LU1 2.4GHz 1mW USB Wireless Data Transceiver Module
[Edit 2]
Following irongiant33's advice, by increasing the RF gain in SDR#, I'm now able to see a much clearer signal from my remote control, though still need to hold it pretty close to my antenna.
I'm struggling to install and use the software recommended for demodulation (NRF24-BTLE-Decoder). While on Windows, I received an error message indicating "gcc" is not recognized. It seems I need to download additional software, but I'm not familiar with Github repos and dependencies.
Understanding that I'm a relative beginner, any advice on these challenges would be greatly appreciated! Here are some specific areas where I could use some guidance:
- Data Export from SDR#: How to properly extract the captured data for further use.
- NRF24-BTLE-Decoder Installation: Help navigating Github and installing the software on Windows (or if using the Raspberry Pi is a better option).
Thanks :)
22:55 UTC
USRP - 2974 FMCW Radar
Hi all, I am pretty new to use of SDR and am trying to build a FMCW Radar for Object Detection and this has been my setup
my setup consists of an USRP-2974 which connected to an UDBox and a BBox one Beamformer, transmitting at 28GHz, and am receiving the following Outputs
and a Range resolution of
with object distance from peak of beat_signal as
can someone help me to verify if my gnuradio setup is correct. My beamformers are placed 22inch apart with an object at 5 inch distance
23:02 UTC
which sink I should use for hackRF microwave transmition?
SDR is very new thing for me. And I decided to build BPSK modulated signal transmitter with Hackrf.
In all guides that I found people use osmocom sink. Didn`t find it in block list.
13:47 UTC
USRP X300 - no ping
Hi all!
I got USRP X300 and cannot ping it. I tried to reflash FPGA with newest HG image (UHD 4.7.0), but still no reponse from unit. My interface is configured with 192.168.10.1/24 address. I'm using SFP-T SF-CP100C-GP (SFP-to-RJ45 converter) on SFP0 port. Seems X300 see sticked SFP (green led on). My PC NIC interface supports up to 2,5Gb and patchcord Cat6.
Does anyone know how to handle this bricked unit? I got only HW without power supply, SFP converter and other accessories attached to it. Now I'm wondering if my SFP converter is supported by X300 (I cannot find any info about it). I tried 10Gb on SFP 1 port with DAC cable and still nothing (ip 192.168.40.1).
12:02 UTC
Cannot recover the entire file via QPSK in GNU Radio, using LimeSDR
Hi Everyone, I'm trying to use GNU Radio to create a QPSK flowgraph and am testing it by sending a file (>10k words) via SDR. Now I have noticed that I am able to receive most of my data successfully, but the last couple of chunks (1k words) seem to go missing. I am not sure why this is the case, as I've tried sending small files & large files but the problem still remains that the last chunks do not get picked up by the receiver.
I have tried this with/without using packets and the problem still remains. Perhaps there is some setting in the buffer or something that I need to fix but I'm not sure. Does anyone have an idea why this could be the case? I am using the examples shown in https://wiki.gnuradio.org/index.php?title=QPSK_Mod_and_Demod page.
Here is my transmitter part of the code
And the receiver
05:57 UTC
USRP X410 unreachable
My device is a USRP X410. When I tried using uhd_find_device, I encountered the following results. I attempted three methods: performing a factory reset with usrp_update_fs, updating the file system with the mender system, and directly refreshing the eMMC, but all resulted in 'unreachable.' I can SSH into the internal system of the USRP, which indicates that the network connection should be fine.
Please help me; I’m overwhelmed by this issue
10:12 UTC
Add oot modules to gnu radio windows version
Hey all!
Is there any guide for building oot modules for the windows version? I have found a repo with some oot modules that fits my needs, but I cant find any building guide for this version. I know that for the linux version is easy but I want it for the windows version cause my pc is already slow so in a vm machine is terribly slow.
15:57 UTC
GNURadio and hackRF jamming program for drones
Hello everyone! I have a project for my bachelor degree where I have to jam a drone that fly over an unauthorized place. I have to use GNU and hackRF to jam it and make it stop working. The drone that I'm using is a cheap one, that costs less than 30 euro. I will be in a classroom and demonstrate it in front of the commission. The thing is that, the drone operates at 2.4ghz and when I want to activate it, I will send an white noise signal for let's say 5Ghz and it will stop working because of jamming, making it lose contact to my remote and this is how I will demonstrate it works. The problem is that I tried to run it without my hackRF hardware because I don't have its possession yet, so I used QT Gui Sink block instead of osmocom sink block, but it doesn't work. When I run the program it gets blocked at 0Ghz, it doesn't fluctuate at 2.4ghz, it just stays at 0Ghz. I don't know what is the problem, maybe a block not configured well or maybe I have to add or remove a block. Can sb help?
13:51 UTC
GNU Radio on windows 10 64-bit
Hi there, i was wondering how to install gnuradio on windows, does anyone has a link for that, or a video tutorial?
Thanks in advance
13:12 UTC
Unable to perform AM modulator in gnuradio
i was following this video on youtube .https://www.youtube.com/watch?v=FxzB8kpYE5k
his diagram was
his output is
but when i did the same circuit .
i am not getting correct output
please help me urgently
Thank you in advance
15:37 UTC
Bind python to C++ in GNU Radio
Hey, any help to bind python and C++ in building GNU custom blocks? I'm trying to add a library to my GNU radio. Have the codes to built the blocks but it's extension is python. cc , can't understand how to bind the files.
10:57 UTC
USRP (custom ports) to audio sink?
Hi all
I am trying to work out if this software can pipe audio in and out of chan_USRP in asterisk.
I'm looking to achieve this:
Audio line in -> conversion -> USRP 192.168.0.10:32001
USRP 192.168.0.10:34001-> conversion -> Audio line out
Is this possible please? I've had a look around the software but I cannot work out the settings.
Thank you!
06:39 UTC
Help needed GNU radio FM
I needed to do one project on gnu radio in the topic presence of noise in FM reciever.. Can anyone have to know how implement this.. Please shoutout..
16:32 UTC
Change default editor in python block
my GNU radio python block default editor is set to Notepad, but I would like to change it to another editor. However, when I check the options for selecting an editor, I don't see any Python specific editors. Any help to solve?
03:25 UTC
Reading data from BPSK modulated signal
I'm receiving wireless BPSK signal with RTL SDR.
I want to demodulate and see the bits/bytes. How can I setup blocks to extract bits/bytes?
Is the .dat a right format to do this at file sink?
18:59 UTC
Send "value" to GR block from C++ using UDP
Hi all,
I am trying to send the frequency value of the GR "Signal Source" block from an external C++ code, using UDP.
So far I can send UDP packets (as arrays of bytes) to GR from my C++ code, but I don't know how to extract the value for the frequency and how to pass it to Signal Source input. If I understood correctly, the parameter "frequency" is a GnuRadio message type, so I need to convert the byte(s) I send with UDP into a GR message, but I am not 100% sure if this is correct and how to do it.
Any help would be greatly appreciated.
Thank you
16:50 UTC
pluto+ and gqrx
does gqrx work with pluto sdr ?
if so, what is the device string for plutosdr ?
21:35 UTC
Decimation not affecting to length of signal
I'm using rational resampler to apply decimation and convert sample rate to 48k Hz which is the sample rate that signal originally generated from.
However, even I applied rational resampler, the signal length is same as when the sample rate is 1,008,000 Hz. I'm expecting the signal play time to be longer. How can I play original signal length from the rightmost Frequency Sink?
Thanks for your advice in advance.
20:28 UTC