No word on whether the DS4 is CGround or CLine? So lazy to go to the store lol.
I posted it elsewhere. Its common ground. L1/R1 are active high though and need inverting.
Sony trolling with the trigger buttons.
I think the reason L1/R1 are active high is because of the way the traces are routed on the plastic sheet. L1/R1 kind of get trapped from the traces the L2/R2 need since its analog. They couldn’t route the ground trace to L1/R1 without having to add extra pins and inserting extra ground traces making it crowded on the plastic sheet. So they just use the vcc that the L2/R2 use since its right there.
I just want to point out and congratulate Sony on their improvement on the DS4’s shoulder buttons. For anyone who has ever opened up a DS2 and/or DS3 they know how terrible it was putting the shoulder buttons back into place when its time to close up the pad. Fear not, for those troubling times are gone when dealing with the DS4. All four shoulder buttons stay firmly attached to the plastic frame that the button sheet lays against.
Finally. That was the one aspect I HATED about DS2 and DS3, was those damn shoulder buttons. The DS3 also took it a step further and included super shittier versions of the triggers when the DS2 buttons were not only easier to put back in, but also way better feeling to play on.