This may be a dumb question, but… can the X2 controller pass audio / video signals through it? For example, if an electret microphone sends the voltage signal into the analog input on the controller board, can that be sent to, for example, a speaker, or computer speaker, and reproduce the audio? …or, do you just get some voltage readings?
It is kind of a dumb question, at least in the sense that it suggests your actual question is something other than what your wrote. What does it mean to pass audio or video signals? A wire can do that, so presumably, you are asking for something more, like some kind of processing or manipulation of the signals. But, if we’re talking about a digital, programmable system, that does mean you would be working with “just some voltage readings”. However, the processor on the X2 is not powerful enough to do any meaningful processing of those voltage signals by itself; the limit of what you can do is something like detecting a frequency and then generating some simple melody in response. The X2 could also control some peripheral modules that are made specifically for video or audio; for instance, the X2 could control an MP3 player module or a video text overlay module to have it display the temperature read off of some sensor connected to your X2.
Sorry if it wasn’t clear. What I meant is, for example, is that I’d like to, ultimately, stream an audio signal that enters the microphone (electret, or whichever), in via the analog input, out via the USB cable and capture the stream on the PC, either as a live stream or an audio file. And, can it go the other way, from the PC microphone (or audio file), in via the USB cable, out via an analog out to an attached speaker?
You’re still asking the X2 to process the data, which it is not going to do as well as something made for this sort of thing. Some limited stuff is probably doable, but you would need to have a level of expertise where you wouldn’t be asking these questions (or at least would be asking more specific questions). The microcontroller can certainly sample incoming signals at up to a few tens of thousands of samples per second, but how much of it you can get out over USB while doing anything else useful is up to you. And, if you aren’t looking to do anything else useful, there are more effective things to get than the X2 (for instance, the SVP-1284 has USB and other better features at a lower price as long as you don’t need the big motor drivers of the X2).