Random outcome on multiple devices

[Darrel Taylor]

I think this would be the same as giving the PIC a fixed seed in the code.

Exactly!
Using the U2's incrementing serial number ... Each PIC has a "Fixed Seed".
But each of the 32 PICs are guaranteed to have a different seed, therefore a different blink pattern on power-up.

They are all running the same sequence of 65535 pseudo random numbers, but they all start at a different point in that sequence.