Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

COM and USB port protocols

Status
Not open for further replies.
I'm hoping someone can help me!

I know that a COM port on a PC uses RS232 protocol to communicate with external devices etc. But what does USB use? Is it the same as RS232, or does it have a different protocol? If so, does anyone know what it is? Thanks.

Any info will be appreciated.
 
the usb is a million times more complicated than RS232... Don't have any real helpful info for ya... but it's not anywhere near as simple and elegant as RS232. a whole lot faster, though, of course.
 
USB uses.... I guess USB.

However, you can buy converters to plug into the USB which will give 1 (or more) RS232 ports. Also converters from USB to parallel (Printer).

JimB
 
USB uses an encoding technique called NRZI, it's serial just like COM... only, different format, works at different voltage levels a different way, etc...


usb.org is a good place to find stuff, alot of it is mumbo jumbo advertising type of things... but you can find the full data sheet specs for USB on there if you look hard enough.
 
If you look on the Microchip website they have an application note for their USB capable PIC's (the 16C745) - this shows what's required at both the PC and PIC sides.

As already suggested, it's a LOT! more complicated than RS232.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top