----- Original Message ----- From: "Alan B. Pearce" To: "Microcontroller discussion list - Public." Sent: Friday, May 13, 2005 11:22 AM Subject: Re: [PIC] RS232, USART, and COM > >Why does pc com port use RS232, is there a standard that requires this. > > Yes, the RS232 standard. This is a standard originally set up for computer > equipment to talk to modem equipment, and has become the defacto voltage > interface specification for serial interfaces that connect outside computer > cabinets. There are other standards, but this is the generally the > commonest. Yes, you are right, tnx. > > >On the other hand, why do the pics use uart without rs232, is this > >a pic problem which will make it more complex to connect to pc? > > So does the UART inside a PC. There are other chips that do the conversion > to RS232 voltage levels, just like using a MAX232 with a PIC. > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > > > -- > No virus found in this incoming message. > Checked by AVG Anti-Virus. > Version: 7.0.308 / Virus Database: 266.11.9 - Release Date: 12/05/2005 > > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist