I have a circuit which uses two 5 VDC PSUs to power a few addressable LED strips each and one is connected to an Arduino controlling them. Both PSUs are connected via the same 120 VAC input.
I've noticed that the LEDs only seem to respond correctly when the LED power is hooked up to the same PSU as the Arduino.
From what I gather I need to connect the -V terminals of the two power supplies together so they have the same base "reference" point but I have seen conflicting/confusing information about the safety of this, depending on the specific configuration of the PSUs. (See some of the comments on this question: Can I connect two power supplies' GNDs together?)
For reference: the PSUs in question are two Mean Well RSP-320-5 and from what I've read they aren't configured to be completely connected in parallel (+V and -V shared between supplies), but I wanted to double check that connecting the -V terminals is the right move before I fry something.