UART communication without UART port

[prabhukaran3]

Dear Friends,

Greetings..!
Currently I am working with PIC16F877A controller.. I already used UART port (RX,Tx pins for Max232(Rs232 Communication). Still i need to add Max485 connection for long range communication.. Without RX and Tx how can I connect.. But i am damn sure its possible... Because i am having a circuit board in hand. Which consist of RS232 and RS485.. It is connected ( RX and Tx for RS485 ) with B port...I think B0,B1... Is there any suggestion regarding that.. I need Pin detail regarding this query. And more if we do so and so, is it possible to communicate through RS485,RS232???

Kindly help me... Thanks in advance

 

[andre_luis]

If you are using CCS C compiler, the serial communication API already performs the handshake of non-legacy USART ports.
Just setup a different port that the built in ones.

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[prabhukaran3]

Dear Andre_teprom

I am a hardware designer.. Don't know very deep about Compiling process and Software coding.. So kindly send what are all the pins needed to connect RS485 other than UART pins... And need reason for selecting those Pins...

 

[nandhu015]

Search for the term soft uart in google.

Normally you can use any free io for this purpose. If your micro is busy doing something else you need interrupt pins.

I advice you to use UART port for rs485 and soft uart for your communication.

Hope this helps

 

[gizdawg]

I'm using CodeWarrior IDE, and the built-in True-Time simulator for my design. I'm trying to get a message across the UART functionality, but since its a simulator, the code will continue to loop until a TX/RX is passed. How do I emulate this?? Thanks.

 

[andre_luis]

You must choose some OUT pin to work as TX and an IN pint to work as RX, but this one must have avaliable Interrupt-on-change feature.
If I remember correctly, at PIC16F877, port B comply with this requirement.


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