Image v1.4 on RPi3B+ does not work.

Discuss KerberosSDR - 4x Coherent RTL-SDR
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f4exb
Posts: 9
Joined: Wed Sep 04, 2019 11:51 am

Image v1.4 on RPi3B+ does not work.

Post by f4exb » Thu Sep 05, 2019 7:35 pm

Hello,

I just flashed the .img file on a SD card plugged in the SD card connected Ethernet and Kerberos and applied power. The Rpi gets an IP address in my network and is reachable by ping. Howver I cannot conenct via ssh (Connection refused) and cannot reach the web application on port 8080 and I cannot connect to the WiFi hotspot. Like this the image is totally unusable.

Brgds.

f4exb
Posts: 9
Joined: Wed Sep 04, 2019 11:51 am

Re: Image v1.4 on RPi3B+ works but may be improved.

Post by f4exb » Fri Sep 06, 2019 12:04 am

Hi,

Well eventually I could make it work. SSH daemon is not activated by default so with a keyboard and display connected to the Pi I could enable the ssh service (sudo systemctl enable ssh) so that it would start at boot up. I may suggest to have ssh service enabled by default in the next version of the image to avoid confusion. The doc says there is a ssh access so I would expect it to be there at first boot up. Also I could eventually connect to the WiFi hotspot and access the web app.

While having ssh out of the box could be really nice I rapidly realized that working in a remote console is not tremendously useful when it comes to running the kerberos eco system itself that requires the desktop environment on the Pi. However it would be nice to be able to have the equivalent of the host Python app as a web application to be able to calibrate and control from a connected phone or tablet. That would save some of the processing power necessary to run graphics on the Pi.

Brgds.

rtlsdrblog
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Re: Image v1.4 on RPi3B+ does not work.

Post by rtlsdrblog » Fri Sep 06, 2019 10:58 am

There is a web interface for KSDR. Once setup a connected to the hotspot (or modified to connect to your wifi) you can controi it via he web interface. Web interface URL & Instructions at www.rtl-sdr.com/ksdr.

f4exb
Posts: 9
Joined: Wed Sep 04, 2019 11:51 am

Re: Image v1.4 on RPi3B+ yes it does work

Post by f4exb » Fri Sep 06, 2019 4:15 pm

Hi,

thanks for the info but I am still confused about the web interface is the port 8080 or 8081? (I may try both anyway) I could not get to the page that shows all options I just had the DOA and Passive Radar links.

Once the very first issues were solved I could have a quick check with a crude arrangement of 4 identical vertical rubber duck antennas in circle and it is working well showing solid different DOAs for different UHF (~400 MHz) transmitters although that was indoor so possibly with some reflections. I could actually notice secondary peaks when moving around so it seems quite sensitive.

Brgds.

f4exb
Posts: 9
Joined: Wed Sep 04, 2019 11:51 am

Re: Image v1.4 on RPi3B+is useless

Post by f4exb » Fri Sep 06, 2019 9:45 pm

Hi,

so... 8080 port has all the features and 8081 is for the DOA compass. So I could eventually use the web interface for control. However after some time trying either with the web interface or the Python host interface I eventually gave up. I am sorry but the software is not convenient whatsoever. It is a nightmare to operate and unless you know exactly what frequency to look for and you calibrate once and for all it is not really usable. It does not even have a NCO so you have to spot exactly the signal on the zero IF and calibrate then do it all over again for another signal even in the same pass band of the RTL-SDRs. So I am sorry but I now keep the Kerberos in storage in hope for better software support in the future.

Brgds.

rtlsdrblog
Site Admin
Posts: 2478
Joined: Mon Nov 19, 2012 11:54 pm

Re: Image v1.4 on RPi3B+ does not work.

Post by rtlsdrblog » Sat Sep 07, 2019 8:58 am

Yes please remember this is still experimental beta software. We're the only trying this open source so it will still take a while to get the software as newbie friendly as possible, but the reward will be that anyone can build on the software. Right now we're still focusing on the features and functionality.

For now I always recommend that people wanting to play with KerberosSDR be interested in exploring and testing new things, and don't want something that is just a button press to work.

f4exb
Posts: 9
Joined: Wed Sep 04, 2019 11:51 am

Re: Image v1.4 on RPi3B+ does not work.

Post by f4exb » Sat Sep 07, 2019 11:08 pm

Hi,

this is fully understood and I think the hardware is great. I still went far enough to see it is actually working. The idea of having an embedded noise source and the careful crafting of couplers is essential to make interferometry affordable to the masses. It is also great that the software is open source and one can always tailor it to its own needs. I am not giving up on it and have plans to include support in my own software but it is not quite ready yet for this sort of device.

I have also plans to make an add on with 4 microwave SMA switches to help with the calibration in order to switch between antennas and loads without manual intervention (this is the most cumbersome part). Of course this sort of thing cannot be included in the package within the same price envelope as the switches alone cost about the price of the Kerberos itself (you need good quality switches at ~40 USD each).

Brgds.

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