AVR-Chat

I think if you look at their specifications you'll see that both are 
essentially the same as far as communication mechanism goes in that 
they're both designed for separate transmit and receive line pairs.  
National Semiconductor has a good application note, AN-759, that 
compares the 2.

Perhaps Leon meant that RS-485 can be one way.  It is used that way in 
some applications.


REB



Tim Mitchell wrote:

>Leon wrote:
>  
>
>>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. 
>>    
>>
>
>No, RS485 is not one-way, each node can transmit or receive. You are
>thinking of RS422 which has separate inputs and outputs.
>
>
>  
>