[En-Nut-Discussion] RS485 Multimaster protocol

[Piotr Szlachta]

Hi

I got one :) 

It's multimaster, but has fixed frame length with 4 bytes data field.
Developed for '51, ported on Atmega128. Runs under Nut/OS.

There is one problem, source code is not documented AT ALL. All in my mind. 

I'm planning to make documentation and share code, but not soon. Next year
earliest. 

Did you think about CAN? If I today start with home-automation project I
would use CAN instead of RS485.

More about project: www.homeautomation.pl

Contact me on prive. I'll send you source code for my protocol and try to
help you with implementation if you stay sticked to RS485. 
My advise: CAN.

Regards
Piotr.

> -----Original Message-----
> From: en-nut-discussion-bounces at egnite.de [mailto:en-nut-discussion-
> bounces at egnite.de] On Behalf Of Hugo Simon
> Sent: Sunday, October 14, 2007 1:34 PM
> To: Ethernut User Chat (English)
> Subject: [En-Nut-Discussion] RS485 Multimaster protocol
> 
> Hi,
> 
> has anyone implemented a Multimaster RS485 half duplex protocol on the
> Ethernut2, complete with collision detection? I want to use it for a home
> automation system. The protocol should be run also on non-Ethernut nodes.
> The Ethernut should become a webserver/RS485 gateway which I use to
> control
> my home via a Nokia Internet Tablet.
> 
> The protocol should be able to send short packages up to 256 bytes from
> one
> node to another and from one node to all nodes (broadcast). It should
> detect
> collisions and do a retransmit then.
> 
> It would be nice if I haven't to reinvent the wheel.
> 
> Thank you
> Thorsten
> 
> 
> 
> 
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