Re: [avr-chat] UART: 9600 baud limit

[Michael Hennebry]

On Thu, 17 Apr 2008 address@hidden wrote:

> I'm working with an ATmega32 on an STK500, and also on a breadboard which
> is the eventual target. I've been struggling to get UART to work, and now
> that I did succeed, I can't get a baud of more than 9600. Now, with the
> STK500 and the software clock, I get get 38400 - 115200, but with the
> external oscillator plugged into the STK500 board I simply cannot achieve
> more than 9600.
>
> Anything more than 9600 results in garbage. Yes, I'm setting my terminal
> emulator accordingly.
>
> I *am* using an external oscillator, running at 8.0 Mhz.

Have you tried 40000 or some other factor of 8000000?
The baud rate has to be at least approximately
a factor of the oscillator frequency.
8000000/38400 and 8000000/115200, being larger than 50,
are both within 1% of an integer,
so I'm not sure that that is the problem.

-- 
Michael   address@hidden
"Those parts of the system that you can hit with a hammer (not advised)
are called Hardware;  those program instructions that you can only
curse at are called Software."