AVR-Chat

----- Original Message ----- 
From: "magzky02" <magzky02@yahoo.com>
To: <AVR-Chat@yahoogroups.com>
Sent: Wednesday, February 28, 2007 7:49 AM
Subject: [AVR-Chat] When boyscouts say one for all, all for one


>
> hello guys,
>
> i have a system that has 1 master microcontroller that communicates to
> 18 slave microcontrollers. I am going to use a USART in UART mode.
> Since the master is using only one UART, there are control lines so
> that the communication b/n slave and master is one at time to avoid
> corruption. My question is that is this method reliable? When one
> slave controller transmit (toggling the lines high and low), hows does
> other slave controller affect the data? will they hold the line high?
> Any idea?
>
> consulted mr google and seems rs485 is one solution.

It was the Three Musketeers!

RS-485 is one way. You could also daisy-chain the slaves and use the UARTs, 
with each slave passing the message onto the next. You will need some sort 
of addressing system; when the correct slave identifies the message, it 
performs the desired action otherwise it passes it on to the next slave.

Leon
--
Leon Heller
Amateur radio call-sign G1HSM
Yaesu FT-817ND transceiver
Suzuki SV1000S motorcycle
leon355@btinternet.com
http://www.geocities.com/leon_heller