Is there a way to tell if something's being control by an analog or digital input without knowing and understanding all the rest of the circuitry involved?
I have a Wowwee robot (Elvis) that I'm trying to interface with an arduino, so I can "parasite" onto it and control its functions (very simply).
I've hooked in my multimeter to the output pins that head toward the motors (and their respective circuit boards). I get a signal of mostly 3.3v, but occasionally it dips down in the 2's and 1's. Now I know this looks like analog, as digital would just be 3.3v or 0v, but I'm wondering if it's still a digital signal just being PWM'd...?
I just got a logic sniffer/analyzer. I've been trying to interface it with the Elvis to see what the output's looking like on the pin(s), but I've been having other issues with the logic analyzer (and noisy, ungrounded pins). But I digress.
So is there a way to tell if this is an analog signal that's actually moving up an down the range between 0v and 3.3v, OR if it's still a digital signal that's just being pulsed fast enough to "effectively" be/look like an analog range?