I found a super easy way using the MAX233 chip. You just run a wire from the TX on the 628 to the TTL input on the MAX233, and run the +/-10V output to an RS232 port. The MAX233 is a pretty cheap level translator (free samples at www.maxim-ic.com) and comes in an easy to use 20-pin DIP. Of the 20 pins, I usually only connect about 4, the rest are for advanced users I guess. Plus the 233 has built in charge pump capacitors, so it doesn't need any external components to do its job. In all it probably takes up less board space than anything I could cobble together, and it supplies true RS232 +/- 10v. Oh and did I mention the free samples? ----- Original Message ----- From: "Mark Mynsted" To: Sent: Friday, April 16, 2004 12:05 AM Subject: [EE:]TTL to/ From rs232 for 16F628 circuit > I am new to this and want to be able to connect my circuit to my pc to > provide nice informaiton for debugging etc. The 16F628 has a AUSART but > I need to alter the voltage. > I found the following here at piclist: > http://www.piclist.com/techref/io/serial/ttl-rs232.htm > > TTL To/From rs232 > http://www.botkin.org/dale/rs232_interface.htm > > This looks great, but has anybody else used this? I thought that > MOSFETs were really sensitive to ESD. I really like the low cost, few > parts, and no electrolitics. (In case I want to later embed in potting > resin.) > > Also I could not find the exact MOSFETs he shows. Locally I can get NTE > semiconductors from FRYs (at high cost) but I am not sure if their > NTE491 is really the same. Is it close enough to work? > http://www.nteinc.com/specs/400to499/NTE491.html > > (I may get these from Dale's site but I would rather get the parts now, > and not use paypal.) > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads