In the simplest terms, I2C can be achieved with 2 wires, and SPI with 3 (DI and DO can be commoned up). However, the code (firmware) required to drive I2C is significantly more than with SPI. So, if you are running short on I/O, I2C is good. However, if you're short on code space, SPI is the better bet. Of course, if you micro has an I2C peripheral, you're in the pound seat. But beware, many of the PIC devices have a SLAVE I2C peripheral, so if you are implemeting MASTER I2C, you need to write the firmware anyway. regards Ian Rozowsky Engineering Manager Centurion Systems roz**@centsys.co.za ||Anti-spam - please remove the ** from the e-mail address before sending|| http://www.centsys.co.za ----- Original Message ----- From: "Colin Constant" To: Sent: 05 February, 2002 01:29 Subject: [PIC]: I2C vs SPI pointer? > Can some kind soul please point me to something online that explains I2C vs > SPI? > > LIN and CAN would be great, too, but I don't want to push my luck. :-) > > I feel like I've been going around and around at microchip.com. > > Thanks, > Colin > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email listserv@mitvma.mit.edu with SET PICList DIGEST in the body > -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu