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asjad
Joined: 09 Mar 2004
Posts: 52
Location: Greater Manchester - UK
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| Test my code |
 Posted: Sun May 23, 2004 11:02 pm |
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Dear All,
I have a nasty suspicion that my programmer is not working, could someone please test my code i.e program a chip:
PCM V3.168
PIC16f874 - USING 4MHz crystal, LCD connected to port D - using ccs drivers.
I can either send the HEX file, the source file
Many thanks for responding
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asjad
Joined: 09 Mar 2004
Posts: 52
Location: Greater Manchester - UK
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| code |
| Posted: Sun May 23, 2004 11:24 pm |
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| Code: |
#if defined(__PCM__)
#include <16F874.h>
#device ICD=TRUE
#fuses XT,NOWDT,NOPROTECT,NOLVP,NOPUT,NOBROWNOUT
#use delay(clock=4000000)
#endif
#include <lcd.c>
#byte INTCON = 0x0b
int sec=0; //second
int min=0;//minute
int hrs=0; //hour
int milli=0;
int increment = 0;
int flag=0;
int data=0;
void display()
{
lcd_init();
if (flag==1)
{
lcd_gotoxy(0,1);
printf(lcd_putc,"%02U:%02U",hrs,min);
}
else
{
lcd_gotoxy(1,1);
printf(lcd_putc,"%S",data);
}
}
#int_rtcc
void clock_isr()
{
increment++;
if (increment==2)
{ milli++;
increment=0;
}
if (milli==10) // 10*100ms = 1second passed
{
sec++;
milli=0;
}
if (sec==60) // 60*1sec = minute
{
sec=0;
min++;
flag=1;
}
if (min==60)
{
min=0;
hrs++;
flag=1;
}
if ((hrs==24) || (hrs && min==0)) //24:00 - reset all variables and place 0:00
{
sec=0;
hrs=0;
flag=1;
}
if (milli < 10) //milli lower than 10 exit after incrementing milli
set_RTCC(60); //setup TMR0 to count upto 100ms
}
void main()
{
INTCON = 0xa0;
setup_counters(RTCC_INTERNAL,RTCC_DIV_256);
set_RTCC(60);
while(1)
{
if (flag)
{
display();
flag=0; // clear new data flag
}
}
}
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THANK YOU[/code]
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asjad
Joined: 09 Mar 2004
Posts: 52
Location: Greater Manchester - UK
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| Function |
| Posted: Mon May 24, 2004 12:32 am |
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The above progrsam is a simple implementation of a "Real time clock"
I have tried to programming it myself,
but unfortunalty I get unexpected results
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Mon May 24, 2004 1:38 am |
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What "unexpected results" do you get? Can you be more specific?
| Code: | | if ((hrs==24) || (hrs && min==0)) //24:00 - reset all variables and place 0:00 |
This looks suspicious; every hour (except 0:00) you will reset all variables.
Also you call Display only when flag==1, so in Display() you will only display the time. never the line with Data.
Last edited by ckielstra on Mon May 24, 2004 1:52 am; edited 1 time in total |
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asjad
Joined: 09 Mar 2004
Posts: 52
Location: Greater Manchester - UK
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| Posted: Mon May 24, 2004 1:45 am |
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After I have programmed the PIC and pressed reset it takes about
8 seconds for the program to start, when it does start the seconds go
twice as slow
I have calculated that an interrupt should occur every 49ms, my clock
increments every 2 ISR calls i.e 100ms
I have checked clock, PSU, connectivity,LCD
I have not enabled the powerup timer
Regards
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rwyoung
Joined: 12 Nov 2003
Posts: 563
Location: Lawrence, KS USA
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| Posted: Mon May 24, 2004 7:36 am |
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Why call lcd_init() each time you run display()? lcd_init() should be called once near the start of your main()
Ignore the LCD for the moment and ignore your clock variable values. You say it is running too slow? Check your crystal value, check your capacitors (or your resonator as the case may be). Is it correct? You indicate a 4MHz crystal and you have the XT fuse which is correct. Use an oscilloscope and x10 probe to check that the oscillator is running. Probe OSC2 which I believe is the "driven" pin but check the PIC data sheet to be sure. You can probe either pin but probing the non-driven pin is more likely to affect the measurement.
Use one of your I/O pins as an output and each time through your interrupt toggle the pin's state. Use an oscilloscope to check that it is running at the correct speed.
Something else to check. Turn off your interrupt and modify your main() to call display() over and over and over. Add two lines to your display() code for this test. First instruction in the subroutine should set that pin high. Last instruction before leaving the subroutine should set that pin low. Use your oscilloscope to time how fast the routine is running. Is it taking longer than the interrupt period? Alternatively you could look at the LST file and count cycles but this is faster. There is a little bit of error associated with the overhead of toggling the pin, 2 cycles if you are using fast I/O, 8 (I think) if you are using standard i/o
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Rob Young
The Screw-Up Fairy may just visit you but he has crashed on my couch for the last month! |
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