Hey everybody, just getting into this whole hardware engineering thing as a
hobby.  I have one quick question that I couldn't find the answer to
anywhere.  Here's the scenario:  I have a computer sending data to a thermal
printer over an RS-232 serial line (think retail POS.)

Is it possible to probe the Tx line (from the computer) and "sniff" the
serial data without disturbing the connection between the computer and
printer? I am using the newer 8 and 14 pin pics.  Here's a simple schematic:

        -->   01000110101010 (data) -->
[COMPUTER] Tx +------+--------+ Rx [PRINTER]
                     |
                     |
                     +
                   [PIC] - 01000110101010 (data)

As I said, I'm just getting into this, so I'm not exactly sure which way to
do this (if at all possible.) Would I simply use a regular digital input,
analog input, analog w/ comparator (I need to find out what a comparator
is.)  Also, will I need to use some sort of amplifier to make sure the
signal between the computer and printer is unaffected?  Thanks,


-- Jeff

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body