I can't argue with that, as long as I have knobs to turn and displays to read. But a headless radio that is only controlled by a PC is something that I cannot do.
So it is interesting that lately I've been looking at some of the homebrew SDR projects that are out there. This is a field that has a level of maturity now that it's (seemingly) straightforward to begin exploring.
One project in particular has caught my attention. The T-41 SDR based radio kit that has been advertised by the 4-Square QRP Club
The issue with this kit is that the parts (BOM) are lagging because of supply chain issues getting the parts. That is understandable and not too much a concern. The folks who are driving this project are doing an excellent job of managing the situation and I'm completely confident that those who are lucky enough to secure a kit will be pleased. I'm not on "the list" because there is no list. It'll be sort of like a Pile Up to determine which lucky ham can get a kit. I'm hopeful, but not banking on it.
In the mean time I am looking into their software and made a recommendation that they put the source code for the BSP on GitHub, which they have done recently. But I think there needs to be some tweaking to the repository and other things to make it easier to access (i.e., build).
I've forked the repo and will be making my contributions through PRs in the days/weeks ahead.
In the mean time of that I also have been looking into the basis of the SW package that they are using and stumbled (perhaps incorrectly) across a few things.
Namely, the core software seems to be based on (or influenced by?) an SDR project from DD4WH.
On that repo, I found some key information --
The basic HW platform that would be needed, and some of the hardware systems that go along with it -- like the display and SDR Quadrature Sampling Detector, and some other things. Unfortunately the SDR QSD they are using in that project is out of stock in the supplier so it will be a bit of a challenge to replicate that design.
Also, I am going to have to upgrade the HW platform from Teensy 3.6 to 4.1. The MCU are close enough. The ARM Cortex M4 and ARM Cortex M7 aren't that dissimilar except for some underlying IO and addressing of registers that are specific to each specimen. I'm not too worried about that port-over.
The Project then I have started is trying to bootstrap a SDR from what I can get my hands on and adapt from the existing repositories (the ones listed above) to make something from nothing.
I have two things on my side. One is a career worth of experience in embedded software. (Day job is making rocket engine controllers and other embedded software systems for space, so I'm not at all daunted by the port of the embedded side of things). The other plus is that I have a lab at home that has all the tools and test equipment I'll need to build it and test it. It'll be interesting!
At the end of this, or at least at a major milestone of this Project is copious amount of documentation that I plan on producing that will help anyone else "start from zero to get to SDR". I think a lot of the projects are put together very well. One critique is only that the projects aren't (apparently) really designed to be portable (not physically portable -- I mean adaptable to slightly different MCU based systems that are fundamentally very close). That's the work I hope to zero on. I may not know enough yet about the actual SDR code base to make that statement correctly, but I think I'm right from the things I've read so far.
We wouldn't be in this position if it wasn't for the excellent work and development by MANY who have strived to make SDR projects something for the common-ham. I do sincerely appreciate the work that has been done and have utmost respect for their work.
I am going to try to carry things further. As the Old Bard says, "Build on the Work of Others".
That's exactly what I intend to do.
More later.
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