PIC I/O...

[syntium87]

i'm using pic16f877a and mplab to program the pic....
i got this problem..how to set one of the pic port to become input and output together..?(like set a pic port pin that can be input and output)..
can it be done??
wht should i write on the c program??? help pls...

[Brian Griffin]

i'm using pic16f877a and mplab to program the pic....
i got this problem..how to set one of the pic port to become input and output together..?(like set a pic port pin that can be input and output)..
can it be done??
wht should i write on the c program??? help pls...

You cannot make the port pin to become input and output together. But however, you can turn it into an output or an input one at the time.

Input : TRISX.RY = 1
Output: TRISX.RY = 0

(X denotes the Port, and Y denotes the pin number/bit)

Hope that helps.

[syntium87]

so,it means that i cannot set it as a bidirectional(input and output) pin port?

i just read this data from microchip website...
http://www.microchip.com/forums/tm.aspx?m=147534&mpage=1&key=PORT,PROBLEM,16F870&

chapter 9 i/o considerations --> bidirectional port


it said in can be set..but i dont know how to write the code in c..help me...

[syntium87]

sorry...wrong link...
this is the microchip website link

http://ww1.microchip.com/downloads/en/devicedoc/31009a.pdf

can such operation being used on pic16f877a?
c code???

[yonghui]

Hi,
most PIC ports are bi-directional digital input output pins, but there is no need for bidirectional at one time.
set it to input when we need it as input, and set it to output when we need it as output. we can switch it as input or output very fast.
only some port pins are unidirectional, one example is the port pin which share with master clear, MCLR pin which can only be set to digital input.

regards,
yh

[Brian Griffin]

I haven't heard of an I/O pin can become an input and an output at the same time. Normally, it's one at the time.