Ignore Andy as you will be scratching your head until you realise that RS 232 is inverted. And the MAX * chips are cheap, maxim sends free samples out and all it costs you is some typing on a web page and a few days later they are at your door (IIRC you can get 8 chips at a time) Yes you can use discrete transistors to invert the signal, yes most "New" equipment accepts 5v RS 232, but older equipment will not, an old Wyse terminals etc (some ppl use them with monitor programs, some external modems (one model (number I do not recall) of netcomes will not work on new PC's without a level converter. Andy the reply I sent was correct for the question asked, and follows good engineering practices of following standards. Regards, Kat. ____________________________________________________________________________ The information contained in this email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please promptly notify the sender by reply email and then delete the email and destroy any printed copy. If you have received this email in error, you must not disclose or use this information in any way. ____________________________________________________________________________ ----- Original Message ----- From: "Andy N1YEW" To: Sent: Saturday, September 08, 2001 7:29 PM Subject: Re: [PIC]:Simple RS232 hardware > Andy Shaw wrote: > > Resent missing header! > > Hi Folks, > > I'm sure this must have been covered before but a search of piclist.com > > failed to find anything... Anyway what would you recommend as the > > simplest/minimal hardware RS232 interface for use between a PIC and a > > modern PC? This is *not* for a production product I would just like to be > > able to include a very cheap interface on a home project for occasional > > diagnostic/config use. Can I get away without using a MAX* converter? What > > are the pros/cons? What would be your suggested circuit? > > > > Thanks > > > > Andy > > Ignore Kat, and try this: > > PC: PIC: > TX ---|>|--/\/\/\------ PIC RX > | > GND-/\/\/\- > > RX---------------- PIC TX > > Works for me every time. > > andy > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu