Quote Originally Posted by karenhornby View Post
Whats the best pic that will do the following:
compatible with a DS18B20 for temperature measurement
It's not the PIC that fullfills the requirements for being compatible with the DS18B20...it's the keyboard operator.

4 input pins (simple high or low inputs)
4 output pins (simple high or low outputs through transistor switch to operate relay)
6 Pins for an LCD (4 bit mode)
gonna be working with an 8Mhz resonator because no crucial timings involved.
http://www.microchip.com/ParamChartS...g=en&pageId=74

A 16F628A handles everything but the 8Mhz (has 4Mhz internal)
Once you need an 8Mhz internal and small, as in 18 pin package,
http://www.microchip.com/ParamChartS...g=en&pageId=74
2 pins power/ground, internal 8Mhz, 14 I/O + a pin for the DS18B20...
18F1220/1230/1320/1330...
No pins wasted...small package...

It's all in the parametric search pages at www.microchip.com