----- Original Message ----- From: "Tom" To: Sent: Monday, June 23, 2003 5:50 PM Subject: [PIC]: simplest USB add on to existing design > Problem: > The formerly ubiquitous RS232 serial ports on PC's has become > "un-ubiquitous" replaced by the now even more ubiquitous USB port. > > We have many products that used 232 to talk to PC's; what is the easiest > way to modify them for USB operation? And by modify, I mean production > wise, not just one or two. > > What I'm wondering about is putting a USB adapter chip on my circuit board > (no dongles or external adapters). Where a PIC used to go through > something like a MAX232 level shifter to the board edge, I now want to put > something perhaps like the FTDI245BM chip. Or a Microchip part. Or a > Cypress part. Or ? > > Is it possible to just buy a chip solution and put it on the board such > that I talk to it via my serial data lines so my PIC code is for the most > part unaltered? Yes, completely unaltered if you want. > And furthermore, is it possible to do so without needing > to write PC-side drivers or know about descriptors or other USB stuff? For > many of my applications, data rate equivalents of around 9600 to 115,200 > will do fine. And for some, very low amounts of data; maybe 10 to > 100Kbytes total at a connection. Bit-bucket apps. Yes, with no trouble. > I'm guessing this has been addressed by a large-ish subset of PIC'sters by > now. Thanks for any ideas here. > > Tom M. The FTDI RS232 chip is your friend here. Bob Ammerman RAm System -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.