SDRplay Community Forum

I've revisited using SDRPlay devices as scanners a number of times. The goal has been to build a remotely accessible web based scanning interface with low latency audio for use on my LAN.

Using a Raspberry Pi to host the scanning app with it's web GUI and audio server and use serial CAT commands to control SDRuno, SDRConsole, HDSDR and Cubic SDR and check out their relative merits has been the approach so far.

But the end of the road has been reached. Without a "BY;" CAT command the time delay in querying received signal levels and halting the scanner is too great and too unreliable a measure of a busy frequency.

SDRuno so far offers the most promising solution, it runs very nicely with only the MAIN window open, or MAIN + VRX, as per the pic below which is happily scanning across any combination of frequencies at a rate of 120 milliseconds per frequency, and that's on a Windows virtual machine.

Please could the SDRPlay development team give consideration to implementing support for a BY command.
- it would set the SDRuno software apart from all the others
- you know you need it too for implementing scanning yourself, if that's still on the agenda

My suggestion is to implement a BY as readable but ALSO to provide the option via a check box in your SDRuno CAT settings to automatically send the BY state after every FA / FB CAT request.

Remotely polling for a BY would be next to useless and defeat it's purpose - as you'd be aware normally a BY is sent automatically in the AutoInformation mode - so sending it after any CAT fx change would solve that.

If that was to be implemented it would present an opportunity for anyone with the ability to write native code (not me, he said enviously) to build a neat little scanning app and save you the considerable trouble of trying to add it to SDRuno, as well as to build stuff on a Pi as I have.

Sincerely, Phil VK7JJ

The pic shows two overlapping windows with SDRuno running on a remote machine in the radio shack, visible in a VNC window on my Mac inside the house. The scanner software is running in a web browser on the Mac. The Pi is in the radio shack connected to the SDRuno machine via CAT.

Hello Phil,

I like what you've done there. As you know, SDRuno does respond to BY; but always sends back a "Not Busy" response. Having a status event from the API is something that we are in discussions about. It would certainly help in situations such as this. Once that is available, then implementing BY; as you suggest is something we could certainly do.

I would like to try out what you've put together, could you send me some details? (software@sdrplay.com)

In the longer term, I have always planned to extend the CAT control (like a CAT+) so that applications can access more of SDRuno's front panel (especially where the RSP control is concerned). Having been through this process, I'm sure you have ideas on that

I just want to stress, this is a long term goal and would have to fit around other previously planned updates. Scanning, for example, is something that is coming in the next release of SDRuno. However, I like the cross-platform nature of what you've done. Thanks for sharing.

Best regards,

Andy

Hello Andy, thanks for that. Email sent.

Haven't addressed the central issue of how best to extend uno CAT, you are obviously right on the mark with your comments and know how it fits with your other plans.

"BY" would be the simplest quick fix from my POV but if you are looking at making changes to that part of the code base then it's worth a lot more thought to get the best return on the smallest coding investment and maybe also come up with something a bit more inspirational.

Personally I see CAT as a fallback from my preferred option of direct TCP access to SDRuno because that would be much more elegant and would do away with the complication of serial cables and speed; you'd be freed from having to conform to Kenwood CAT limits and provide direct access to the most relevant bits that are already available in your API; it would also avoid the problems inherent in multiple serial demand wars and user configs.

But CAT is effective as the lowest common denominator, it allows any sort of frequency controller/scanner/file handler app as per my code to work with any ham radio hardware whether it is an SDR or otherwise and that's a nice incentive for a coder, and a great thing to have around the shack.

Regards, Phil VK7Jj