AVR-Chat

> On 5/30/07, dlc <dlc@frii.com> wrote:
>> I've gotten 9600 baud to work well with the internal 1MHz oscillators of
>> the Tiny11.  You can handle quite a bit of slop reading serial data if
>> your baud rate is low enough.
>
> Unfortunately, clock speed error is proportional, so 5% error is 5%
> error in baud rate, no matter what baud rate you pick.  But, as the
> baud rates get higher, the granularity of the steps in the UBRR
> setting get proportionally larger (ie: 20 vs 21 is smaller error than
> 3 vs 2)

  There is no hardware UART in these small chips, I bit bang my serial
there and that seems to be more tolerant of bit slip and stretch.  Being
in software gives me the option of very high granularity.  The hardware
UARTS are not as tolerant of error.  That is probably the difference.

DLC
--
Dennis Clark