RS485 interface with pic microcontroller

Status
Not open for further replies.
M

M.Imran Ali

Member level 5
Joined
Sep 28, 2012
Messages
86
Helped
3
Reputation
6
Reaction score
3
Trophy points
1,298
Activity points
1,814
I want to interface RS485 with pic18f452 . But when i send data the same data is available on the receiving pin of microcontroller and a logical contention is also there? why?
 

The selected IO pin must be dedicated to the serial (RS485) communication
 
I think you should post your schematic that you done to receive anybody's help!
 

But when i send data the same data is available on the receiving pin of microcontroller and a logical contention is also there? why?
Click to expand...
What do you mean with logical contention?

I presume you are using a RS485 transceiver, it has TE (transmit enable) and /RE (not receive enable) pins that must be controlled by the µC. A popular method is to connect both pins to transmit enable, so when TE is asserted while sending, the receiver is also disabled at the same time. A pullup resistor is additionally needed at the transceiver RX output to keep the inactive high state.

In some applications, it's however wanted to receive while transmitting to check for possible collisions.
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…