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10F202 I/O problem

 
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SveinR



Joined: 04 Aug 2005
Posts: 9

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10F202 I/O problem
PostPosted: Thu Aug 04, 2005 3:39 pm     Reply with quote

Hi!

I'm just playing around with the !0F202, and I cant get det GP2(B2) pin to act as an output, only as an input.. I have made an silly easy code to only blink with some leds to test this..

"
#include "10F202.H"
//#fuses NOBROWNOUT,NOMCLR,NOWDT,NOPROTECT,NOPUT
// Skal benytte 4MHz kystall.
#use delay (clock=4000000)

PORT_B_PULLUPS(TRUE);


void main(void) {

while (TRUE) {

// BLITZ BLÅ LYS

output_bit( PIN_b0, 1);
output_bit( PIN_b1, 0);
output_bit( PIN_b2, 1);

delay_ms (50);

output_bit( PIN_b0, 0);
output_bit( PIN_b1, 1);
output_bit( PIN_b2, 1);


delay_ms (50);


}
}//Slutt main()

"

Using CCS v 3.212

Regards
Svein
PCM programmer



Joined: 06 Sep 2003
Posts: 21708

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PostPosted: Thu Aug 04, 2005 8:16 pm     Reply with quote

I don't have the PCB compiler, so I can't check the ASM code,
but it's possible that CCS doesn't initialize the OPTION register
properly. Upon power-up reset, the OPTION register is initialized
to all 1's. This will make GP2 into an input. It overrides the
normal TRIS.

To fix this problem, you need to set the T0CS bit in the OPTION
register = 0. This requires ASM code. CCS has a macro for this,
as shown below.

Try adding the following code to your program and see if it works.
I've also set it to enable the pullups, because you showed that
you wanted to do that in your post.
Code:

#define set_options(value)   {#ASM         \
                              MOVLW  value \
                              OPTION       \
                              #ENDASM}

//==============================
void main()
{
// Enable GP2 for i/o, and enable weak pullups.
set_options(0b10011111);   


while(1);
}
SveinR



Joined: 04 Aug 2005
Posts: 9

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PostPosted: Fri Aug 05, 2005 5:25 am     Reply with quote

Okey!! I will try this when I get home from work. THANKS Very Happy

But in that TRIS register, do it control the other pins? And do you set the GP0 an GP1 also as output??

Why wont the SET_TRIS_B comand work?

Regards
SveinR



Joined: 04 Aug 2005
Posts: 9

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PostPosted: Sat Aug 06, 2005 5:06 am     Reply with quote

It works!!! THANKS A LOT Very Happy
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