Use two pins for TX. One for RS232 ground and one for the RS232 RD (the TX
signal). Ground high and TX low for mark, Ground low, TX high for space.
(thanks to Steve Walz)

See:
http://204.210.50.240/techref/default.asp?url=io\serial\ttl-rs232.htm

---
James Newton mailto:jamesnewton@geocities.com 1-619-652-0593
http://techref.homepage.com The Technical Details Site.
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-----Original Message-----
From: pic microcontroller discussion list
[mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Tony Nixon
Sent: Tuesday, January 18, 2000 18:21
To: PICLIST@MITVMA.MIT.EDU
Subject: serial port


Is it worth dispensing with the 232 chips for PIC to serial port
connections?

I've seen countless simple interfaces that must work, or they wouldn't
be around.

I can see the RX working OK if it's inverted with a tranny, but does the
TX work after inversion when it can only be pulled down to 0 volts.

--
Best regards

Tony

http://www.picnpoke.com
mailto:sales@picnpoke.com