@szakib more options you say? More options it is: I used fre:ac when I switched the laptop to Linux (but only a few times until now).

@ScruffyBrush ah cool, didn't know there is a new one out yet, mine is the old one with a RP2040.
That looks so nice, what are you running on it?

@nytpu for the nostalgia: Borland C++ Builder's WYSIWYG editor (the same one that also was in Delphi) was peak for me as a teen trying to make some small Windows programs.
Here's your window. Want a button? Drag one from the toolbar to where it should be. Oh, it should do something when you click? Just double click it and it adds a OnClick method to the UI class, and places the cursor right there so you can start writing code.
Want to create everything from a loop in the code? Sure, just copy that Button code block and replace some values with variables.
Of course that was way before HiDPI or responsive layouts (the newer versions had some flow layout container).
And the whole UI was somehow translated into native elements on application start - it was contained as source in the resources of the .exe, so it could even be hacked after compiling.

@eniko @Njord I was tasked with presenting the enocean protocol and the constraints it has in my university wireless comms class.
Quite fascinating, how it manages to plan for tiny amounts of energy and even does AES and repeated transmissions on 868 MHz with that. Of course, the downside is that the receiver end needs to be powered, as it must catch the random transmission whenever you press the button.
They do have other energy harvesting devices as well, like using solar cells indoors, or temperature gradients

@ret searching for the text, some of the other modules I found the wires listed as being Vcc, Gnd, and "enable", and the device itself as being a CW transmitter. So it probably is just that, a bit of power management, oscillator, amplifier. If the enable is fast enough, it could maybe be used as a CW/OOK transmitter. But I wouldn't be surprised if it just takes a while to get to steady state, so maybe not so useful outside its suggested main use

@ret the lower half though, seems like it could generate something on its own. The input wires don't look suitable for an RF input for just being an amplifier (unless one of then is a coax, hard to see), and the part in the left side could be some oscillator?

@ret maybe the circulator then is used as a safety against reflected power, if no antenna is attached or it is mismatched. Or the block next to it could be a connector on the other side, which would then lead to a receiver?