nmeyer
Joined: 09 Jul 2004
Posts: 70
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| Timer0 set up for 18F4520 |
 Posted: Tue Nov 06, 2007 2:26 pm |
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I am trying to use the rtcc timer in my program by setting up a rtcc_isr. HOwever, something is not running correctly. When i put in code for the correct number of interrupts per second, it runs way too slow. This is the first time i have used the 18F4520, so i am wondering if i am missing something in the set up of the chip. Can anyone quickly look through this code and see if there is a noticable error? I have used this timer isr in other programs (pic16F819) and it worked fine.
Compiler PCWHD V4.06
| Code: |
#include <18F4520.h>
#device adc=10
#include <stdio.h>
#include <math.h>
#FUSES NOWDT //No Watch Dog Timer
#FUSES WDT128 //Watch Dog Timer uses 1:128 Postscale
#FUSES XT //High speed Osc (> 4mhz)
#FUSES NOPROTECT //Code not protected from reading
#FUSES NOBROWNOUT //No brownout reset
#FUSES BORV25 //Brownout reset at 2.5V
#FUSES NOPUT //No Power Up Timer
#FUSES NOCPD //No EE protection
#FUSES STVREN //Stack full/underflow will cause reset
#FUSES NODEBUG //No Debug mode for ICD
#FUSES NOLVP //No low voltage prgming, B3(PIC16) or B5(PIC18) used for I/O
#FUSES NOWRT //Program memory not write protected
#FUSES NOWRTD //Data EEPROM not write protected
#FUSES IESO //Internal External Switch Over mode enabled
#FUSES FCMEN //Fail-safe clock monitor enabled
#FUSES PBADEN //PORTB pins are configured as analog input channels on RESET
#FUSES NOWRTC //configuration not registers write protected
#FUSES NOWRTB //Boot block not write protected
#FUSES NOEBTR //Memory not protected from table reads
#FUSES NOEBTRB //Boot block not protected from table reads
#FUSES NOCPB //No Boot Block code protection
#FUSES LPT1OSC //Timer1 configured for low-power operation
#FUSES MCLR //Master Clear pin enabled
#FUSES NOXINST //Extended set extension and Indexed Addressing mode disabled
#use delay(clock=4000000,RESTART_WDT)
#use rs232(baud=19200,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8,RESTART_WDT,ERRORS)
#define INTS_PER_SECOND 1 //should be(4000000/(4X256X16))=244.14
//#include <Flex_LCD.C>
int i,step,phase1,phase2;
char reply,int_count,loop_int;
int byte1,byte2,byte3,byte4,byte5,byte6,byte7,byte8,byte9,byte10,byte11,byte12;
int byte13,byte14,byte15,byte16,byte17,byte18,byte19,byte20;
int rbyte1,rbyte2,rbyte3,rbyte4,rbyte5,rbyte6,rbyte7,rbyte8,rbyte9,rbyte10;
int rbyte11,rbyte12,rbyte13,rbyte14,rbyte15,rbyte16,rbyte17,rbyte18,rbyte19,rbyte20;
long crc_result,seconds;
int16 crc,r_crc;
int32 tempbyte,disbyte,mult;
////////////////////////////////////////////////////////////////////////////////
#int_rtcc
clock_isr()
{
if(--int_count==0) //decrement counter until 0
{
++seconds; //count up seconds
int_count=INTS_PER_SECOND; //reset counter
if (seconds>=65000)
seconds=65000;
}
}
////////////////////////////////////////////////////////////////////////////////
void main()
{
setup_counters(RTCC_INTERNAL,RTCC_DIV_16);
set_rtcc(0);
enable_interrupts(INT_RTCC);
enable_interrupts(global);
set_tris_b(0b00000000);
output_low(PIN_B5);
int_count=INTS_PER_SECOND; //used for timer
seconds=0;
while (true)
{
if (seconds<=1)
output_high(PIN_B5);
else
output_low(PIN_B5);
if (seconds>=3)
seconds=0;
}
} |
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