Connection detection?

[void_error]

Actually the problem was solved quite a while ago, see above and here. The only thing I didn't know how to do is detect which two sockets are connected together.

[SL4P]

Ok, so you're good. (Sorry I missed post #15)
Post your block schematic and we can add / comment on your plan.
What you need to be prepared for is using pins for BOTH in and out at different times - or spring for a larger pinout package.

[void_error]

Ok, so you're good. (Sorry I missed post #15)
Post your block schematic and we can add / comment on your plan.

No need to, I've tested it and it works. Already done writing the code for it. Next step is designing a PCB. Did I mention this has to be 2xAA battery powered? Using a MCP1640 to boost the voltage.

What you need to be prepared for is using pins for BOTH in and out at different times - or spring for a larger pinout package.

Easy. Used the TRIS registers to change pin direction when needed.