On Sat, Jun 26, 2004 at 03:10:02PM -0700, Bob Axtell wrote:
> Kyrre Aalerud wrote:
> >Hehe.
> >If only I could get my LV ICSP to work I could test the loader...
> >
> >BTW: If you have a system where you will be using a RS232 connection, why
> >not use that as the bootloader ?
> >Saves all the other pinns for regular I/O :)  (That's why I made mine USART
> >based.)
> >
>
> The main advantage of the UART method is that in the application itself,
>  the RS232 has to be used anyway, to perform the objective of the
> product. Having the UART already setup for periodic updates makes
> Kyrre's scheme more attractive, to me.

See my other post. This presumes that the application's RS232 target and the
development RS232 target are the same. Fine for datalogging for example. But
if the the application wants to use the USART for MIDI, or a modem, or a
RS232 LCD panel, or to drive a IR/laser wireless interface, or to use an
XPORT ethernet to get connectivity, then the bootloader will be in conflict
with the applications use of the USART.

With a soft bitbanged interface, the USART can be dedicated to the application
as opposed to having to share it. You also get a free debugging serial port
for the application too.

Just a couple of pennies for the pot.

BAJ

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