> > Hi, I wonder what is the fastest reliable speed for RS232 com.
> > that is common for pic projects?
> >
> > I need to 'talk' to a PIC18F458 (@20MHz) as fast as possible and
> > reliable. Hoping to avoid handshake lines. Much of the data will be
> > sent/recived to the canbus at the same time.
> >
> > Would be greateful for serial com. code examples in Microchip C18


> I've done 115,200 baud reliably on a 18F452 with a 18.43Mhz crystal
> using HiTech PICC, all interrupt driven.
>
> One thing to check is the accuracy of the frequency division for the
> UART generator.   I figured I could do 115K baud reliable with a 20Mhz
> crystal (about 3% error), but the EE in charge wanted to have an "exact"
> frequency division for baud rate accuracy.
>
> Also, is your data "bursty" or continuous?  If it's continuous, your
limitation
> may be processing speed and not the reliability of the RS232 link.
>
> A checksum byte and an ACK byte are very useful in your comm protocol,
> to make sure you receive valid data and the sender knows it.

Hi
The data is 3 to 5 bytes max in a 'burst' and very little has to be done to the
data. Basically just send/read from the CANbus or write/read Port A-E.
So 115200 baud would be approx max. - that speed is most likely okey
for my purpose.

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