max485 recieve mode problem

[amintlk]

hi all
i use max485 for rs485 communication ... it works correctly but i have little problem ... i tied RE and DE to one of microcontroller pin to control transmitt and receive mode .. and pin 1 called "RO" is for receive data over the rs485 and it's idle high and it connect to RX pin of microcontroller .. but when i switch to transmitt mode for send data "RO" pin is going to idle low until max485 switch to Receive mode again .. what can i do for hold "RO" in idle high always ???
thanks

 

[babar_ali]

Hello!!! Read the document this will help you.

http://www.ti.com/lit/an/slla272b/slla272b.pdf

Enjoy!