USB2 being a limiting factor, no matter the app, it would still be cool as a tool to have your smartphone run your LimeSDR in some way.
Thatâs what prompted me to look into this (seeing the demo of QRadioLink), but not all phones are capable of being rooted. The Samsung Galaxy J7 is one of them - the key to that phone not being able to be rooted is the lack of the âOEM UNLOCKINGâ option not being part of the Developer Options - so rooting isnât an option for me (or anyone else running a 2 GHz octo-core Snapdragon processor) on this phone being used as a development platform. This may continue to be a problem for future users if âOEM UNLOCKINGâ is not part of the intrinsic properties of the processor and the OSâŚIn effect itâs âgame overâ a the get-go. Additionally, some with newer (and more expensive) phones may not want to have the possibility of losing their warranty if the phone is rooted (most carriers will deny replacement if the phone has been altered from its original âout the doorâ state). And the worst of all scenarios is that once the user decides to root their phone, if it doesnât work theyâll either have to reload their OS for the phone (best case) or will have a fairly expensive brick in their hands (really worst case). Given all that, it seemed a more likely path is to just develop an Android app that will allow operation without rooting a phone and without having to use a helper app (VNC Viewer) to open the Linux desktop from Android.
I did try the âDebian No-Rootâ Linux on my development phone (the J7) but it was incredibly slow to respond to launching a terminal and it left me with the impression that running an app that requires near real-time speed to process the streams from the LimeSDR or LimeSDR-Mini would be impractical on that version of Linux (thereâs no guarantee itâll even run and many other users reported slow operation of that Linux distro, too).
While Iâd love to be able to run already established apps that run on Linux on a smartphone using a rooted phone, I think thereâs merit to running an âhonest-to-Godâ Android app made to perform with the LimeSDR or LimeSDR Mini without taking risks associated with rooting ones phone.
73 de Marty, KN0CK
I think the solution to that problem is using hardware that respects the userâs rights even if that means staying behind in the technology curve.
@adim - Adrian,
All good - Iâm not trying to imply that rooting an older phone isnât in my field of view, too, just for the sake of research. But for covering the fair amount of Android users that are out there that want an easier method of obtaining LimeSDR and Lime-Mini capabilities on their smartphone theyâd opt just to install an .APK file and be done with it - Thatâs where my attention is focused at the moment.
73 de Marty, KN0CK
I have an idea, a programmer friend of mine said he thinks one of the chips on the Lime is pretty advanced and could hold the software needed to run it.
If that were the case, maybe the user interface could be on an android, and the real processing done on the board. So perhaps the USB 2 wouldnât be a bottleneck.
Thoughts?
I guess he thinks that there is enough of the FPGA to run an OS? I am not in that world, but some FPGAs have processors & some donât, as I understand. Iâll look at the datasheets, but I do not think this one does. Of course, there is always the C language class, but I am not sure what can be done with this chip.
Not a bad idea. But, then you would need so much hardware to support it all. It then changes the intent of the product.
Still not a bad idea at all. I say to integrate the LimeSDR, full sized (Classic, I guess?) circuitry into a Nvidia Jetson TX2 module. I mean, interwoven in the fabric of it. Not just a daughterboardâŚ
That would be the bees kneesâŚ(If someone decides to, I want a freebee for the idea)
Ed
Based on previous experience with this subject, If I were to start all over again I would change a few things architecture-wise. You should take a look at what the big boys are doing with this: https://gatehouse.dk/telecom/waveforms/smartphone-sdr-project/
Much more flexible architecture than qradiolink and obviously native Android UI which is something I meant to look into, but it requires much more effort and knowledge of sys internals.
I think these days one must resist cramming as much DSP logic in the FPGA as possible, because while efficient it reduces the flexibility as the design - build - deploy cycles become longer.
Iâm sure Andrew here with his domain experience could comment on this topic. The idea of having a small satellite terminal based on the LimeSDR-mini sounds appealing.
Best,
Adi
Hello everyone 
this is my first post (google translate)
This post is a bit old, but I decided to log in here to describe my attempts with LimeSDR mini on adroid (OnePlus 7Pro)
Description âfastâ if someone is interested in the topic, I can develop âŚ
- Install kali Linux on the phone, I recommend ROOT device, although it is not necessary but there are more possibilities
- Run the terminal, install gnu-radio I recommend 3.8, soapy, limesuite, gr-limesdr
- run Nethunter applications on the phone and select KEX Manager - select start server
4.We run the vnc client (phone or other computer) and connect to the phone, run gnuradio, create a project, run the project, save the resulting python file - run Kali nethunter, select CUSTOM Commands, ADD and add the command âpython3 send-wav.pyâ in the send to position: select KALI,
6.the command has been added, just click the added icon to run our project, so you can add hundreds of commands and projects, in VNC mode everything works, in phone mode everything works from the terminal, so without GUI, for some it is an advantage for others: a disadvantage: )
My Lime mini, connected to Oneplus7, receives, records and transmits signals and is powered only from the phone.
If everything is planned and configured, OnePlus 7Pro + SDR is a much more ambitious solution than PortaPack