Which PIC is right for me?

[yjacket]

Thanks for all the responses to my previous question.

I have a circuit that basically has 5 inputs, which have to
be periodically polled and the on/off nature recorded to
a serial eeprom.

Currently, I am using a 16F628A, but I am wondering
whether it would be possible to downgrade to an 8 pin
device.

I use 2 lines to connect to the serial eeprom.

Since 5 + 2 is greater than the # of I/O lines on an 8 pin
device, is it easy to make one pin bidirectional? I am
thinking that one pin could do double duty, but since
all I did was cut and paste the code to interface to the
serial eeprom from a website, I'm not quie sure how to do it
exactly.

Thank you.

 

[Nigel Goodwin]

If you really want to move to an 8 pin device, you could do it very simply using a 12F675. This has internal analogue to digital converters, you could use the 5 buttons to switch different value resistors feeding a single analogue input pin, and two digital pins for the EEPROM.

This would only use three of the available pins.