Brian Kraut wrote:

> Don't know how it will work on 3V, but at 5V you can connect a Pic output
> directly to a 232 input, no resistors needed.  You can connect a 232 output to
 a
> PIC input pin through a 22K resistor.
>
> A computer 232 port will read without doing anything to the RTS, CTS, etc.
> lines, but to get it to transmit you need to connect some lines together, but
I
> don't remember which ones off the top of my head.  Can someone help me out?
>

The short answer is:

Connect RTS to CTS (Request to Send to Clear to Send)
DSR to DTR (Data Set Ready to Data Terminal Ready)
You might also need to connect DCD (Data Carrier Detect) to an asserted pin.

The PC will be a DTE, so it will assert DTR - connect DSR/DTR/DCD

Minimal interface is 3 wires: TxD, RxD and GND.  This is how I have my cable to
the RS-232 interfaced PICs I use..

Hope this helps.
/Kevin