[En-Nut-Discussion] How to add an RS485 interface to ethernut1.3D

Harald Kipp harald.kipp at egnite.de
Tue Aug 2 20:17:07 CEST 2005


Hello Bryan,

If this board is equipped with an ATmega128, then I suggest to
use the second UART for RS485. PD2 and PD3 are available at the
expansion port, so you can wire a simple add-on board with
an RS485 driver like the SP483. This is for half duplex only,
so you need another port pin to switch the direction. PD4 or
PD5 are good candidates.

If you're not familiar with RS485 communication, use Google
and start reading. Specially half duplex is quite tricky.
Fortunately the Nut/OS driver doesn't require a baud rate
dependant delay to switch direction, most desktop computers
do.

Harald

At 13:50 02.08.2005 +0800, you wrote:
>Hello everyone:
>       These days I am working on a ethernut 1.3D board. The embedded 
> programming world is new to me. Is there any possibility to add an RS485 
> interface to the board(as ethernut 2)? I'm not familiar with serial 
> communication and just want to make an easy implementation of  the basic 
> RS485 input and output function. Is there anybody to help me? 
> Thanks!_______________________________________________




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