Re: [PIC]: 16f628A with INTOSC adequate for 9600 serial? by Jan-Erik Soderholm .

Matt Redmond wrote : > >> As someone else has mentioned, the baud rate is > >> irrelevant, the above problem is just as bad at 300 > >> baud and 19200 baud > > Why would that be? Aren't serial bitwidths wider at lower > speeds? Just curious - trying to get an educashun. Yes they are, but the rellative error (in %) is just the same. (bit width vs. bit/baud clock error) Think about it, if you have a 1 meter measuring-tape with an (known) error of 5% (so it's actualy 1.05 meters long), you will still get an error of 5% even when measuring 10, 100 or 1000 meters. In the same way, the *absolute* error in the baudrate clock will add up and give the same *rellative* error at all baud rates. It's a whole other thing if you have "jitter" in the baud rate clock. Jitter tend to even out over time, so in that case lower baud rates might be "better" then higher. But here we are talking about a fixed, stable error in the buad rate clock. Jan-Erik. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads