logic ICs and multiple power supplies - total newbie quandry
Stij
Posts: 2
Hey folks,
So the SX is the ultimate microcontroller - been having a ton of fun with it.· My latest project though is proving unattainable.
I'm designing an sx-based game controller for the playstation2 whose logic states swing from 0V to 3.4V and want it to communciate with the sx on 0V to 5V.· Being a total amateur, I thought I'd run the data/cmd/clock lines, etc. through some op-amps to do the required amping/attenuating.
Now the problem is ground on the PS2 console is not at the same potential as Vss on the sx - leading to different signal references for the data/cmd/clock lines.
To try to be concise:· how can two separate power supplies powering different devices be forced to share the same ground reference without potentially throwing off their original signal-to-ground potentials.
In the event I'm still not making sense:
··· playstation2:··· clock line swings 0-3.4V
··· sx············ :····clock line swings 0-5V
playstation 2 signal ground (GND)·at different potential than sx signal ground (Vss)
op-amps all must have same signal ground as signal reference, that ideally is 0V because I'm trying to run the op-amps off a single supply
Alright - anyone who wants to field this, thanks much!
·
So the SX is the ultimate microcontroller - been having a ton of fun with it.· My latest project though is proving unattainable.
I'm designing an sx-based game controller for the playstation2 whose logic states swing from 0V to 3.4V and want it to communciate with the sx on 0V to 5V.· Being a total amateur, I thought I'd run the data/cmd/clock lines, etc. through some op-amps to do the required amping/attenuating.
Now the problem is ground on the PS2 console is not at the same potential as Vss on the sx - leading to different signal references for the data/cmd/clock lines.
To try to be concise:· how can two separate power supplies powering different devices be forced to share the same ground reference without potentially throwing off their original signal-to-ground potentials.
In the event I'm still not making sense:
··· playstation2:··· clock line swings 0-3.4V
··· sx············ :····clock line swings 0-5V
playstation 2 signal ground (GND)·at different potential than sx signal ground (Vss)
op-amps all must have same signal ground as signal reference, that ideally is 0V because I'm trying to run the op-amps off a single supply
Alright - anyone who wants to field this, thanks much!
·
Comments
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Jon Williams
Applications Engineer, Parallax
Thanks much· - if this were English instead of electronics, I'd be trying to write sentences without memorization of·the entire alphabet.· Long live Parallax!
PS I didn't immediately see anything called the "SX-Key Ring" on the website, but I'll hunt for it.
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Jon Williams
Applications Engineer, Parallax