Computer Interfacing
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rs485 schematic

i am collecting data form microcontroller atmega16 to hyperterminal via rs485.


       Computer Interfacing Forum Index -> RS422 and RS485
Author Message

Apr 10, 2010 8:44 am

i am reciving garbage value at hyper terminal .......therefore i need the proper pin configuration of rs 485. it would be better if some one can explain about RE ,DE,RO,DI....thanx.
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Joined: 16 Jul 2013
Posts: 1
Location: Belgium

Jul 16, 2013 12:51 pm

An excellent datasheet is on doc <.> chipfind <.> ru /pdf/sipex/sp485ecn.pdf
With the external RS-485 wires being A(+) and B(-),
the internal signals for a device using this connection (such as your Atmega), are typically four-fold :
RO = RecvOut : what the RS-485 chip has decoded from the external line, this is being offered to the user
DI = DriveIn : what the user wants to send onto the external line, being input to the RS-485 chip
RE = RecvEnable : whether the user wants to "listen" to the traffic on the RS-485 line
DE = DriveEnable : whether the user wants to "speak" on the RS-485 line, injecting traffic

If your connections were wrong, your hyperterminal would be plain dead. I rather suspect that you have improper communication settings : a wrong guess about the baudrate (9600, 19200, 38400, 57600 bps) - the presence of a parity bit (Even, Odd, or None) - the number of Stop bits (1 or 2).

Hyperterminal allows you to play with these settings.

Sep 23, 2013 10:38 am

lol u r such nerds

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