PIC14000 has parts on chip to make a 16-bit resolution single slope A/D
I just started playing with it.
Parts are:
        Referene voltage
        Temperature sensor
        MUX (8 ext in + internal above)
        Current regulator and discharge for ext slope cap
        16-bit timer with capture register, controlled by
        analog comparator
The A/D slope current regulator is temperature sensitive, so you really
have to measure against the reference voltage often and recalibrate.
There also are two 8-bit D/A and comparators. 0.15 - 0.85 V
And a stupid zener occupies one i/o pin.

The A/D noise in 16-bit measure in my application is about 8 LSB peak-peak,
and then I have done a lot to stabilaze both supply and measured voltage,
so some sort of filtering is needed if using full resolution.

Probably you will nees some external IC to extend number of I/O.
/Morgan

At 09:41 1998-02-09 +0200, you wrote:
>I need some help on my first PIC project.  It might be slightly
>ambitious but what the heck!
>
>My application calls for 2 A/D's, a keypad interface a 5 digit
>(7-segment) LCD display and a pizzo for sound.  It is battery driven and
>battery life is an important issue.
>
>I need some guidelines as to which PIC to choose as well as info on a
>driver for the LCD.
>
>Any help will be appreciated.
>
>Louis
>
>
/  Morgan Olsson, MORGANS REGLERTEKNIK, SE-277 35 KIVIK, Sweden \
\  mrt@iname.com, ph: +46 (0)414 70741; fax +46 (0)414 70331    /