Not sure if this has been covered previously, and I'm not inclined to wade through 500-odd posts this morning, but those contributors referring to an avionics/electronics bay may not all be aware that the A320 has two such compartments separate in the forward fuselage. (Their official names escape me at the moment.)
1) A small bay or compartment accessed just forward of the nose L/G bay (hence roughly beneath the cockpit), accessed by a small plug-type oval hatch in the bottom of the fuselage ;
2) A larger electronics bay/compartment between the nose L/G bay and the forward hold. So it is beneath the forward passenger cabin.
(1) Contains, among other things, the two main batteries, LGCIUs and SEC 3.
(2) Contains, among many other things, the remaining FCCs,
Right now I can't remember where the WHCs are located.