James Corbin wrote:
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Not really an 8052 question necessarily, but I'm wondering what options are available for expanding the I/O ports on a small pinned microcontroller. I'm rather new to embedded development.

If you only need a few extra I/Os, just use a controller with more than the standard 32 I/O pins. You can get the T89C51RD2 in a version with 48 I/Os. You can get chips with up to 64 I/Os from Cygnal and Infineon (Siemens) and perhaps others.

All the examples I see use the 8255, but isn't there a cheaper solution? Possibly built from logic or something?

Don't mention the 8255 here - some people don't like it ;-)

If you need extra inputs or outputs you can use shift registers or 573/574 latches and 244/541 buffers connected to an external memory bus.

Best regards,

Mikkel C. Simonsen