XTALL with serial connection ?
- Is there already a firmware for the pic 12f683 which allows connecting a
serial rs232 line instead of the dip-switch ?
There is an example of a "bitbang" 9600baud rs232 firmware on the
microchip page. From experiments with AVR's i know that a rx-only level
conversion rs232/cmos can be very simple if the firmware is able to read
an inverted rs232 signal.