Hi - I'm not quite sure what you're saying here? Those relay modules (there's a bit of info on http://www.espruino.com/Relays as well) have optocouplers in them already - so if you use those then things are already isolated.
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Hi - I'm not quite sure what you're saying here? Those relay modules (there's a bit of info on http://www.espruino.com/Relays as well) have optocouplers in them already - so if you use those then things are already isolated.