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__JEREK__
Joined: 01 Nov 2006
Posts: 5
Location: Bahia -> Brazil
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| RS232 + getc + 16F876 |
 Posted: Wed Nov 01, 2006 8:59 am |
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Hi there
I'm tring send a mensage by hyperterminal to PIC 16F876 whit crystal 4MHz by rs232.
My problem is some times the pic reset. I make a initial mensage to indicate the de PIC is working, after the program enter in a while loop to reseive a caracter and show the caracter on the screem.
But some times this show the inital mensage and the caracter pressured, showing that the pic was reseted (I think).
the code source:
| Code: | #include <16F876.h>
#fuses XT,NOWDT,NOPROTECT,NOLVP
//#fuses XT,NOLVP,NOWDT
#use delay(clock=4000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7,RESTART_WDT) // Jumpers: 8 to 11, 7 to 12
short int conta=0;
void main()
{
char teste='@';
printf("\n\r+------------------------------------------------------------------+");
printf("\n\rTeste de RS232"); // initial mensage
do {
printf("\r\nValor atual: %c\r\n",teste);
delay_ms(5);
printf("\n\rAperte uma letra: ");
teste = getc();
delay_ms(5);
printf("\r\nA letra foi %c\r\n",teste);
delay_ms(5);
} while(1);
} |
I try make a aplication whit get_string() but don't work fine, now I'm trying make whit getc().
thank you!!! |
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SherpaDoug
Joined: 07 Sep 2003
Posts: 1640
Location: Cape Cod Mass USA
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| Posted: Wed Nov 01, 2006 9:35 am |
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First see if RESTART_CAUSE will tell you why the PIC reset. RESTART_CAUSE is one of the CCS functions. Also make sure you have good power supply bypass caps close to the PIC.
_________________
The search for better is endless. Instead simply find very good and get the job done. |
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__JEREK__
Joined: 01 Nov 2006
Posts: 5
Location: Bahia -> Brazil
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| Posted: Wed Nov 01, 2006 11:35 am |
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SherpaDoug, thank you for your reply!!! I search the CCS exemplo end make the following modification in code source:
| Code: | #include <16F876.h>
#fuses XT,NOWDT,NOPROTECT,NOLVP
//#fuses XT,NOLVP,NOWDT
#use delay(clock=4000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7) // Jumpers: 8 to 11, 7 to 12
short int conta=0;
void main()
{
char teste='@';
///////////////////////////////////////////// NOVO C�DIGO DE ERRO IMPLEMENTADO
switch ( restart_cause() )
{
case WDT_TIMEOUT:
{
printf("\r\nWDT_TIMEOUT\r\n");
break;
}
case WDT_FROM_SLEEP:
{
printf("\r\nWDT_FROM_SLEEP!\r\n");
break;
}
case NORMAL_POWER_UP:
{
printf("\r\nNORMAL_POWER_UP\r\n");
break;
}
// case BROWNOUT_RESTART:
case MCLR_FROM_SLEEP:
{
printf("\r\nMCLR_FROM_SLEEP\r\n");
break;
}
}
///////////////////////////////////////////// FIM DO NOVO C�DIGO DE ERRO IMPLEMENTADO
printf("\n\r+------------------------------------------------------------------+");
printf("\n\rTeste de RS232 N003");
do {
printf("\r\nValor atual: %c\r\n",teste);
delay_ms(5);
printf("\n\rAperte uma letra: ");
teste = getc();
delay_ms(5);
printf("\r\nA letra foi %c\r\n",teste);
delay_ms(5);
} while(1);
} |
now when the pic restart the mensage code is NORMAL_POWER_UP!!! this mean that I have a trouble whith my power supply, I'm right??
thank you for your help!!! |
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SherpaDoug
Joined: 07 Sep 2003
Posts: 1640
Location: Cape Cod Mass USA
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| Posted: Wed Nov 01, 2006 12:26 pm |
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Yes, the PIC is sensing the power interrupted and is starting its program over. How is your circuit built? Do you have an oscilloscope?
_________________
The search for better is endless. Instead simply find very good and get the job done. |
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__JEREK__
Joined: 01 Nov 2006
Posts: 5
Location: Bahia -> Brazil
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| Posted: Wed Nov 01, 2006 12:38 pm |
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my circuit is a programing board, as the picture:
and I don't have oscilloscope, I think now I need make a circuit out of this borad in a protoboar, but I need buy a IC MAX232 to do this!!!
thank you for your help SherpaDoug!!! |
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