pic16f877a input output configuring problem

[Bob Parihar]

i am working on PIC16F877A using mikroc compiler and iam facing a problem in knowing the input output configuration of this micro controller.
My task is simple i am monitring the status of a pin at RC1 by making that pin input using TRISC=1(actually i make the whole port input) and by monitring that pin i want that whenever the pin goes high it should on the lED at Pin RB1

here is my code



sbit b at RB1_bit; // to control led at this pin
sbit a at RC1_bit; // to monitor the push button( i connected on end to the vcc and second end to the pin)
void main() {
TRISB=0;
TRISC=1;
while(1)
{

if(a==1)
{
b=1;
}
else
b=0;
}
}

actually iam getting what i want.. but iam confused because when i press the button a yellow light is shown at that pin when iam using simulator that is PROTEUS 7.
why it is yellow? it should be RED(for logic 1).. by default it is BLUE(for logic 0)

 

[Ian Rogers]

Yellow means logic contention.. Can you show the circuit as drawn in ISIS..

 

[Pommie]

I am guessing that RC1 is bit 1 and not bit 0. Try RC0.

Mike.

 

[Bob Parihar]

I am guessing that RC1 is bit 1 and not bit 0. Try RC0.

Mike.

i have tried PORTB, C and D
and same i expect from port A and E

 

[Pommie]

I don't think you understood my point. You are using bit 1 (RC1) of port C but TRISC=1 makes bit 0 an input not bit 1 as you need.

Mike.

 

[Ian Rogers]

Good spot Mike.... TRISC is only making RC0 an input...

Missed that!!!

 

[Bob Parihar]

I don't think you understood my point. You are using bit 1 (RC1) of port C but TRISC=1 makes bit 0 an input not bit 1 as you need.

Mike.

what i did in my code is..
TRISC=1; // making the whole C port as input( am i right?)
TRISB=0; // making the whole B port as output( am i right?)
now where is the problem?

 

[Ian Rogers]

what i did in my code is..
TRISC=1; // making the whole C port as input( am i right?)
TRISB=0; // making the whole B port as output( am i right?)
now where is the problem?

TRISC=1; // equals 00000001 You need TRISC = 255... All pins