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rezaf
Joined: 12 Oct 2008
Posts: 7
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| problem with timers |
 Posted: Tue Oct 21, 2008 2:18 am |
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Hi .
I am a new C language user and work with CCS compiler. I have an
project that use Timer1 of PIC16F877A and can't use timer. Please help
me to solve my program's problem.
My project:
When program start if pin B4 have input, it will go to s2. In s2 y (is a
Counter) increment and Timer1 start to timing, and save in timer
variable when y=10, the answer of formula s=(10.0/timer); and send
to RS232 port.
But the timer don't start or give random numbers and the answer of formula get wrong.
Thanks for helping me.
my program :
| Code: |
#include <16F877A.h>
#device adc=8
#bit sync = 0.0
#bit BRGH = 1.1
#bit spen = 1.2
#bit txen = 1.3
#bit T1CON = 0.
#bit TMR1ON = 0x0000.0
#bit TMR1CS = 0x0000.1
#FUSES NOWDT //No Watch Dog Timer
#FUSES HS //High speed Osc (> 4mhz)
#FUSES NOPUT //No Power Up Timer
#FUSES NOPROTECT //Code not protected from reading
#FUSES BROWNOUT //Reset when brownout detected
#FUSES LVP //Low Voltage Programming on B3(PIC16) or B5(PIC18)
#FUSES NOCPD //No EE protection
#FUSES NOWRT //Program memory not write protected
#FUSES NODEBUG //No Debug mode for ICD
#use delay(clock=11059200)
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8,stream=Host PC,enable=PIN_B0)
#include <string.h>
#include <stdarg.h>
long int x,a,z,d;
Long int y;
float s;
int32 timer;
void main()
{
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_psp(PSP_DISABLED);
setup_spi(FALSE);
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
setup_timer_1(T1_INTERNAL|T1_DIV_BY_8);
setup_timer_2(T2_DISABLED,0,1);
setup_comparator(NC_NC_NC_NC);
setup_vref(FALSE);
SET_TRIS_B(0x04);
s:{
if ( input(PIN_B4) )
goto s2;
else
goto main;
}
s2:{
do {
if ( input(PIN_B4) )
y=y+1;
if (y==1)
set_timer1(0);
timer==get_timer1();
if (y==10)
s=(10.0/timer);
printf(" s : %f m/s \n\r" ,s);
if (y==11)
y=0;
if (y==0)
timer = 0;
goto main;
} while (true);
}
}
} |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Oct 21, 2008 12:11 pm |
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Nobody wants to look at code that has goto's in it. You need to re-write
your code in the normal C style, without goto's and labels. |
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ECACE
Joined: 24 Jul 2006
Posts: 94
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| Posted: Tue Oct 21, 2008 12:43 pm |
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rezaf,
I'm not sure exactly what is supposed to be happening with y. Like PCM said, you need to learn to put it in normal C style. You have written in more like BASIC. I had a break just now, so I reformatted your code to something closer to normal C style. Now, I will be the first to admit, I am by no means an expert at C, and there are a ton of people here that are 1000% better at C than I am, but it does get you closer to what you want.
I would suggest you pick up Nigel Gardner's PICmicro MCU C 'An Introduction to Programming the Microchip PIC in CCS C'.
Here is your code reformatted. It still needs work with what happens with Y. I just did not fully understand what you wanted to do there.
I have also commented out some things that you shouldn't have set.
One big thing is turning off that LVP...unless your design really calls for it.
Again, I am by no means an expert programmer, in fact I would put myself in a beginner/intermediate level. I also may not be able to answer too many questions, I just had a break right now and had the time. I don't get too many breaks like this...sorry.
Good Luck
| Code: | #include <16F877A.h>
#device adc=8
//#bit sync = 0.0 //Not sure why these were being set,
//#bit BRGH = 1.1 //The #use rs232 will take care of all this
//#bit spen = 1.2
//#bit txen = 1.3
//#bit T1CON = 0. //You don't need to set these either,
//#bit TMR1ON = 0x0000.0 //Setup Timer1 will take care of all this
//#bit TMR1CS = 0x0000.1
#FUSES NOWDT //No Watch Dog Timer
#FUSES HS //High speed Osc (> 4mhz)
#FUSES NOPUT //No Power Up Timer
#FUSES NOPROTECT //Code not protected from reading
#FUSES BROWNOUT //Reset when brownout detected
//#FUSES LVP //Low Voltage Programming on B3(PIC16) or B5(PIC18)
#FUSES NOCPD //No EE protection
#FUSES NOWRT //Program memory not write protected
#FUSES NODEBUG //No Debug mode for ICD
#use delay(clock=11059200)
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8,stream=Host PC,enable=PIN_B0)
#include <string.h>
#include <stdarg.h>
//Variable deffinitions
long int x,a,z,d;
long int y;
float s;
int32 timer;
//Function prototypes of the functions at the end. We can define them here
//so it will compile main(), then actually define the functions after main()
void Setup_Perifs();
void s2();
//Main of program will consist of first setting up the periferals,
//then sitting in a loop at the bottom, checking B4. If B4 goes
//high, then it will execute s2, otherwise it just keeps checking B4
void main()
{
Setup_Perifs();
While(TRUE)
{
if(input(PIN_B4)) //If Pin B4 goes high, then
s2(); //Execute s2, otherwise
} //Keep checking Pin B4.
}
//Functions that are get used in main()
//We can now define them and add some meat to them
//With them down here, they are not locked into main,
//and can be more easily called/modified/coppied.
void s2()
{ //We only got here if pin B4 went high
y++; //So increment Y
set_timer1(0); //Clear timer1
while (!input(PIN_B4))
{
; //Just sit here till pin B4 is released
}
//Only way out of the above loop is if B4 is released
timer==get_timer1(); //Now copy the value inside of timer1
if (y==10) //If y equeals 10, then...
{
s=(10.0/timer); //s will equal 10 divided my what was in timer 1
printf(" s : %f m/s \n\r" ,s); //print out S
}
if (y==11) //If y is equal to 11, then make y equal to 0
y=0; //
} //Now that this routine is done, it will go back to main()
//Setup Periferals of processor
void setup_Perifs()
{
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_psp(PSP_DISABLED);
setup_spi(FALSE);
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
setup_timer_1(T1_INTERNAL|T1_DIV_BY_8);
setup_timer_2(T2_DISABLED,0,1);
setup_comparator(NC_NC_NC_NC);
setup_vref(FALSE);
SET_TRIS_B(0x04);
} |
_________________
A HW Engineer 'trying' to do SW !!! Run!!! |
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John P
Joined: 17 Sep 2003
Posts: 331
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| Posted: Wed Oct 22, 2008 2:01 am |
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Surely
SET_TRIS_B(0x04);
and
input(PIN_B4)
are mismatched?
The SET_TRIS_B command is equivalent to SET_TRIS_B(0b00000100), which sets pin B2 as an input, and all others as outputs.
Beware Bit 4 being taken as the same as a byte with value 0x4! |
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rezaf
Joined: 12 Oct 2008
Posts: 7
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| Hi ECACE |
| Posted: Sat Oct 25, 2008 1:21 am |
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Hi ECACE,
very thanks for your answer, but your code too don't work and the timer variable is always zero.I don't know where of code are wrong. |
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