AVR-Chat

magzky02 wrote:
> I am using a micocontroller to communicate with 18 other 
> microcontrollers via rs489. Using the IC MAX3088, and a 100 ohm 
> resistor across A and B.. Since there are 19 MAX3088, there are also 
> 19 100 ohm in parallel. IS there something wrong with this?

Yes, for a RS485 bus, you usually have one 120 ohm termination resistor
on each end, not on each transceiver. You should also think about
biasing the bus lines in order to have a defined state when no
transmitter is active.

Look at some of the available RS485 application notes.

AS