I could add too, albeit a small tidbit, that you can find EEPOTs with I2C serial interface (2 wire), SPI serial interface (3 wire), and then there is a type that has two digital inputs which act as UP and DOWN controls.

Have Fun....They are very useful devices! Note that if you are designing with one they have a certain number of issues to deal with that the older mechanical pots do not have. One is voltage rating and another is isolation and third is common mode voltage rating. IE do not use an EPOT in a 100V application :-).

And there is another thing to consider in some applications, an EPOT can change its output level from one setting to another in a VERY short time. The slew rate of a mechanical pot is very slow in comparison. Some circuit applications can be unstable with the quick resistance change. If you have that the microcontroller can step the EPOT from one value to another step by step in slow manner.

Michael Karas