Request for help in C coding

[H]

Hi, i m Helen.

Need some help in my project.

I need to design a circuit with coding which voltage as input to tell the pic16f877a to record the time. Then 3 timing is record and calculation will be do after that.

In the simulation i can run the code correctly. However, in pratical i can't get what i want.


The code below:

#include <16F877A.h>
#device ADC=10
#device icd=true
#fuses NOWDT,HS, PUT, NOPROTECT, BROWNOUT, NOLVP, NOCPD, NOWRT, NODEBUG
#use delay(clock=20000000)
#include <STDLIB.H>
#include <math.h>
#include <lcd.c>

#define Full 500 //in mili litre

#define INTS_PER_SECOND 76 // (20000000/(4*256*256))

BYTE seconds; // A running seconds counter
BYTE int_count; // Number of interrupts left before a second has elapsed


#int_rtcc // This function is called every time
void clock_isr() { // the RTCC (timer0) overflows (255->0).
// For this program this is apx 76 times
if(--int_count==0) { // per second.
++seconds;
int_count=INTS_PER_SECOND;
}
}

void main(){

float input_num;
float conv_num;
int i;
BYTE T1;
BYTE T3;
BYTE T4;
BYTE Time_full;
float Cap_per_Sec;
BYTE Total_time;
float Total_capacity;


port_b_pullups(TRUE);
set_tris_b(0xFF);

setup_adc_ports(RA0_RA1_ANALOG_RA3_REF);//AN0);
setup_adc(ADC_CLOCK_INTERNAL);
set_adc_channel(0);

setup_psp(PSP_DISABLED);
setup_spi(FALSE);

int_count=INTS_PER_SECOND;
set_timer0(0);
setup_counters( RTCC_INTERNAL, RTCC_DIV_256 | RTCC_8_BIT);
enable_interrupts(INT_RTCC);
enable_interrupts(GLOBAL);

lcd_init();

i=3;
T1=0;
T3=0;
T4=0;

do {

input_num=Read_ADC();
conv_num=input_num/204.599;

if (conv_num<1.5 && conv_num>1.0 && T1==0){
T1=seconds;
i=i-1;
printf(lcd_putc,"%u", T1);
}

if (conv_num<3.0 && conv_num>2.5 && T3==0){
T3=seconds;
i=i-1;
printf(lcd_putc," %u", T3);
}

if (conv_num<4.5 && conv_num>4.0 && T4==0){
T4=seconds;
i=i-1;
printf(lcd_putc," %u Cap:\n", T4);
}

}while(i>0);

// printf(lcd_putc,"%u %u %u\n", T1, T3, T4);
Time_full=T4-T3;
Cap_per_Sec=Full/Time_full;
Total_time=T4-T1;
Total_capacity=Cap_per_Sec*Total_time/1000;
printf(lcd_putc,"%1.4f liter", Total_capacity);

}

Can anyone solve this problem or give some advise, please.

Thank You.


Sincerely,
Helen
[/code]

[Matro]

First, notice that your code is not endless. So if i <= 0 then your program will exit and the PIC will stop.
My second advise is : indent and comment your code (in english).
That is definitely "unreadable" for us, but maybe for you too...

To debug this program you can comment everything except the first part of the main and test it. If it works fine, uncomment the second part and test again. And so on...

Matro.

[Wayne_]

You included the /code tag but forgot the first code tag

Anyway, do you get any results ?

[ckielstra]

You forgot to set she seconds variable to zero at program start.

[Ttelmah]

Also, read the data sheet about ADC clocks.
ADC_CLOCK_INTERNAL, should _not_ be used on this chip, above 1MHz, unless the processor is put to sleep for the conversion. It is in the notes under table 11-1. You need to be using the /32 ADC clock instead. Generally simulators, won't realise that this is wrong, and will give good results, but on the real chip, it results in really wayward ADC readings.

Best Wishes

[Guest]

[Guest]

[Matro]

The variable called "seconds" is never initialized.

in your first post, you place a "[/code]" at the end but forgot to place the "[code]" tag at the beginning.

Matro.

[tyhon]

you can post circuit?

[Humberto]

[Guest]

Hi!

I still dealling with the same problem. I trying to post the circuit on but I till finding the way to do so.
However, I test the coding part by part. Till the same situation where the timing till display zero. Even I write in most simple coding already.