I need example code ( blink led ) for 12f675 with int. osc

[lychek]

Hi every body,
I'm a new user in PIC. i want to start with PIC12f675 and i try to write the program for only blink the led with internal oscillator. but cannot work.
If any body has an this example please send to me.
thank

[Guest]

Why don't you start with the mid range PIC, there are plenty of forum for
the mid-range PIC in here so it will help you better understand the PIC
with more examples that people has posted here.

[Mark]

Better idea, why not post your code so people can tell you where you went wrong.

[lychek]

Hi,
This is source code that i try to compile and test with PIC12f675

#include <12F675.h>
#device ADC=10
#fuses INTRC_IO,NOWDT,NOPUT,NOPROTECT,NOCPD,NOMCLR
#use delay(clock=4000000)
#define GP0 PIN_A0
#define GP1 PIN_A1
#define GP2 PIN_A2
#define GP3 PIN_A3
#define GP4 PIN_A4
#define GP5 PIN_A5

void init()
{
set_tris_a( 0b11100001 ); // set GP0 output, all other inputs
setup_comparator( NC_NC_NC_NC ); // disable comparators
setup_adc_ports( NO_ANALOGS ); // disable analog inputs
setup_adc( ADC_OFF ); // disable A2D
}
main()
{
init();
output_low( GP2 ); // set low
output_low( GP3 ); // set low
output_low( GP4 ); // set low
while ( TRUE ) // blink LED
{
output_high( GP1 ); // turn LED on
delay_ms( 250 ); // wait 250ms
output_low( GP1 ); // turn LED off
delay_ms( 250 ); // wait 250ms
}
}

No error when i compile this code with ccs, but when i test with ic PIC 12f675 no signal at pin GP1.Could you tell me what wrong with this source code ?
Could you explain me how to set internal oscillator and for 4Mhz exactly ?
thank you
lychek

[Paolino]

In my opinion, if GP0 is the blinking output your code should be:

set_tris_a( 0b11110 ); // set GP0 output, all other inputs

Try like this and let us know.

Paolo.

[lychek]

Hi

i set set_tris_a( 0b11111110 ); // set GP0 input, all other outputs

and i try to blink the led at pin GP1 and GP2 GP3 GP4 is to low. After i test it the result is wrong ( GP1 is not blink and GP3 is High.

i try to change the set_tris_a( 0b11000001 ); // set GP0 output, all other inputs like u told me and the result is the same( GP0 is not blink)

Do you have an other idea or code example for blink the led with use intenal oscillator?

Thank you

KEO Lychek

[Guest]

"set_tris_a( 0b11111110 ); // set GP0 input, all other outputs "

set_tris_a(........GP4, GP3, GP2, GP1, GP0)
and 1 = input
0 = output

if you want GP0 as intput and all others output

set_tris_a( 0b00000001 );

[languer]

Your original code looked fine (your comments were off though). One thing to note is that GP3 is only an input so you can not use it as an output. The following modification should blink your LED on GP1 (modified from your code):

[lychek]

Hi,
I try to compile this code but it doesn't work. but when i delete intrc_io and compile again, it is working.
the code is:

#include <12F675.h>
#device ADC=10
#fuses NOWDT,NOPUT,NOPROTECT,NOCPD,NOMCLR
#use delay(clock=4000000)
#define GP0 PIN_A0
#define GP1 PIN_A1
#define GP2 PIN_A2
#define GP3 PIN_A3
#define GP4 PIN_A4
#define GP5 PIN_A5

void init()
{
set_tris_a( 0b11111101 ); // set GP1 output, all other inputs
setup_comparator( NC_NC_NC_NC ); // disable comparators
setup_adc_ports( NO_ANALOGS ); // disable analog inputs
setup_adc( ADC_OFF ); // disable A2D
}
main()
{
init();
while ( TRUE ) // blink LED
{
output_high( GP1 ); // turn LED on
delay_ms( 250 ); // wait 250ms
output_low( GP1 ); // turn LED off
delay_ms( 250 ); // wait 250ms
}
}

Compiler that i use is PCWH Compiler
IDE version 3.43
PCB version 3.204
PCM version 3.204
PCH version 3.204

After i compile this code, i use icprog to tranfer to ic and i change the oscillator to INTOSC GP4 manually the result is working properly.

When i set the fuse like that #fuses INTRC_IO,NOWDT,NOPUT,NOPROTECT,NOCPD,NOMCLR and then i open icprog the oscillator is set to INTOSC GP4 automatically, the result doesn't work.

Do you know this problem? is from compiler?
Thank you very much

[languer]

Maybe the internal oscillator calibration is lost. Can you read this back from ICPROG?

You could modify the code as follows and see if it works. If it does, the oscillator calibration is most likely lost.

[lychek]

Hi,
I can read the code from ic using icprog.
I try to test ur code that u give me, the led doesn't blink. it's still have problem. How to calibrate the internal oscillator?
Thank

[Mark]

Check the last location and see if it is a retlw instruction. If not, then it is gone. The programmer protects this last location and won't allow you to program it. I have fooled the programmers in the past by specifying a chip that has more memory and then putting a value in there at the correct memory location.

[Guest]

[Mark]

[Guest]