Isn't the so-called EIA/RS 232 in the MCS51 series really an RS/422 because it is only a 5 volt function and not the bipolar EIA/RS232 requirement? I think this is why the MAX232 or other external part is required. Is the only difference between RS/232 and RS/422 the level shifting? Is the protocol the same? Rich ----- Original Message ----- From: "Douglas Wood" To: "Microcontroller discussion list - Public." Sent: Saturday, February 25, 2006 2:08 PM Subject: Re: [EE] microcontroller with built-in RS-485? > I've not ever seen a micro with RS-anything built into the micro itself. I > wouldn't want one, either. If the RS-485 (or RS-422/232/etc.) part of the > circuit got fried, you'd have to replace the entire micro, not just the > much > less expensive transceiver chip. > > ----- Original Message ----- > From: "Jesse Lackey" > To: "pic microcontroller discussion list" > Sent: Saturday, February 25, 2006 10:56 AM > Subject: [EE] microcontroller with built-in RS-485? > > >> Hello all, I often have designs that need rs-485 with some relatively >> simple microcontroller code, and it is always been a two-chip solution: >> 75176 (or equivalent with improvements) and a PIC of some sort. >> >> Does anyone know of a microcontroller with a built-in RS-485 >> transceiver? Ideally it would have a UART (pretty much a necessity, but >> not absolutely required), 16 pins or less, and a decent C compiler >> available from the vendor or 3rd party that doesn't cost a kilobuck. >> Freeware versions limited to say 4K codespace are acceptable. >> >> I haven't done an exhaustive search but I've never seen rs-485 built-in >> to a micro, which is a bit surprising in a way. >> >> Anyway, love to hear anyone's experiences. >> Thanks- >> Jesse >> >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist > > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist