sgtom's Feed - Programmer's Heaven

Help with C programming

Mon, 21 Mar 2011 10:45:42 -0700

Posted a 'new message on the C and C++ forum.

Dear All,

I would like the times to be sent to accumulator register when i press stop button.

how do i go about writting a code in C for that?

I just need the times to be stored in some register and move it to the SBUF register so we can send the times serially.

Please help.

Kindly find my original code below:

#include<reg51.h>
#define msec 1
unsigned int sec1,sec2;
int sec1_1,sec1_2,sec2_1,sec2_2;

unsigned int digi_val[10]={0x40,0xF9,0x24,0x30,0x19,0x12,0x02,0xF8,0x00,0x1 0};
sbit dig_ctrl_1=P1^0; // Declare the control pins of seven segments
sbit dig_ctrl_2=P1^1;
sbit dig_ctrl_3=P1^2;
sbit dig_ctrl_4=P1^3;
sbit start_pin = P1^4; // Start pin to start the watch.
sbit stop_pin = P1^5; // Stop pin to stop the watch.
sbit reset_pin = P1^6; // Reset pin to reset the watch.
int s,t;

void mplex_delay(unsigned int time) // Function to provide a time delay of approximatelty one second using Timer 1
{
int i,j;
for (i=0;i<=time;i++)
for(j=0;j<=50;j++);
}

void digi_out(unsigned int current_num)
{
P2=digi_val[current_num];
mplex_delay(msec);
}

void display(unsigned int dig1,unsigned int dig2) // Function to display the digits on seven segmnet. For more details refer seven segment multiplexing.
{
sec1_2=dig1%10;
sec1_1=dig1/10;
sec2_2=dig2%10;
sec2_1=dig2/10;
TMOD=0x01; //Enable Timer 0
TL0=0xFF;
TH0=0xDB;
TR0=1; // Triger Timer 0
while(TF0==0)
{
dig_ctrl_1 = 1;
dig_ctrl_2 = dig_ctrl_3 = dig_ctrl_4 = 0;
digi_out(sec1_1);
dig_ctrl_2 = 1;
dig_ctrl_1 = dig_ctrl_3 = dig_ctrl_4 = 0;
digi_out(sec1_2);
dig_ctrl_3 = 1;
dig_ctrl_2 = dig_ctrl_1 = dig_ctrl_4 = 0;
digi_out(sec2_1);
dig_ctrl_4 = 1;
dig_ctrl_2 = dig_ctrl_3 = dig_ctrl_1 = 0;
digi_out(sec2_2);
}

TR0=0;
TF0=0;
}

void main()
{
while(1)
{
start: // Segment to start the stop watch
start_pin = 1;
stop_pin = 1;
reset_pin = 1;
dig_ctrl_1 = 0;
dig_ctrl_2 = 0;
dig_ctrl_3 = 0;
dig_ctrl_4 = 0;
P2 = 0xFF;
s = t = 0;
while(start_pin == 1)// Check if start pin is pressed
{
display(0,0);
}

stopwatch: // Segment to stop the watch
for (sec1=s;sec1<=99;sec1++)
{
if (stop_pin == 0 ) //Check if stop pin is pressed
break;
for (sec2=t;sec2<=99; sec2++)
{
if (stop_pin == 0 ) //Check if stop pin is pressed
break;
t=0;
display(sec1,sec2);
}
}
stop_pin = 1;
s = sec1;
t = sec2;

while ( start_pin != 0 && reset_pin != 0 ) //Check if start pin or reset pins are not pressed
{
display(sec1,sec2);
}

if (start_pin == 0) //Check if start pin is pressed
{
goto stopwatch;
}
else
{
if (reset_pin == 0 ) //Check if reset pin is pressed
{
s = t = 0;
goto start;
}
}
}
}

Re: Have a code in C for stopwatch design but have a few problems

Tue, 15 Mar 2011 08:08:38 -0700

Posted a 'reply on the C and C++ forum.

Don't use it. It's not good

Have a code in C for stopwatch design but have a few problems

Sun, 13 Mar 2011 03:37:13 -0700

Posted a 'new message on the C and C++ forum.

URGENT HELP REQUIRED PLZ!

Dear Guys,

The code I have (plz find below) gives me an aprox extra of one second when I press the stop button. eg instead of 0025 it'll display 0125 or. Always an etrxa second added.

Also how do I alter it so that I have the displayed time
"sec" "mili" "mili" "mili" instead of present "sec" "sec" "mili" "mili"

The time is not accurate. It lags when compared to a regular stopwatch.

I need this to be as accurate as possible.

Your time and help is greatly appreciated.

Best regards.

//Program to make a stopwatch

#include<reg51.h>
#define msec 1
unsigned int sec1,sec2;
int sec1_1,sec1_2,sec2_1,sec2_2;

unsigned int digi_val[10]={0x40,0xF9,0x24,0x30,0x19,0x12,0x02,0xF8,0x00,0x10};
sbit dig_ctrl_1=P1^0; // Declare the control pins of seven segments
sbit dig_ctrl_2=P1^1;
sbit dig_ctrl_3=P1^2;
sbit dig_ctrl_4=P1^3;
sbit start_pin = P1^4; // Start pin to start the watch.
sbit stop_pin = P1^5; // Stop pin to stop the watch.
sbit reset_pin = P1^6; // Reset pin to reset the watch.
int s,t;

void mplex_delay(unsigned int time) // Function to provide a time delay of approximatelty one second using Timer 1
{
int i,j;
for (i=0;i<=time;i++)
for(j=0;j<=50;j++);
}

void digi_out(unsigned int current_num)
{
P2=digi_val[current_num];
mplex_delay(msec);
}

void display(unsigned int dig1,unsigned int dig2) // Function to display the digits on seven segmnet. For more details refer seven segment multiplexing.
{
sec1_2=dig1%10;
sec1_1=dig1/10;
sec2_2=dig2%10;
sec2_1=dig2/10;
TMOD=0x01; //Enable Timer 0
TL0=0xFF;
TH0=0xDB;
TR0=1; // Triger Timer 0
while(TF0==0)
{
dig_ctrl_1 = 1;
dig_ctrl_2 = dig_ctrl_3 = dig_ctrl_4 = 0;
digi_out(sec1_1);
dig_ctrl_2 = 1;
dig_ctrl_1 = dig_ctrl_3 = dig_ctrl_4 = 0;
digi_out(sec1_2);
dig_ctrl_3 = 1;
dig_ctrl_2 = dig_ctrl_1 = dig_ctrl_4 = 0;
digi_out(sec2_1);
dig_ctrl_4 = 1;
dig_ctrl_2 = dig_ctrl_3 = dig_ctrl_1 = 0;
digi_out(sec2_2);
}

TR0=0;
TF0=0;
}

void main()
{
while(1)
{
start: // Segment to start the stop watch
start_pin = 1;
stop_pin = 1;
reset_pin = 1;
dig_ctrl_1 = 0;
dig_ctrl_2 = 0;
dig_ctrl_3 = 0;
dig_ctrl_4 = 0;
P2 = 0xFF;
s = t = 0;
while(start_pin == 1)// Check if start pin is pressed
{
display(0,0);
}

stopwatch: // Segment to stop the watch
for (sec1=s;sec1<=99;sec1++)
{
if (stop_pin == 0 ) //Check if stop pin is pressed
break;
for (sec2=t;sec2<=99; sec2++)
{
if (stop_pin == 0 ) //Check if stop pin is pressed
break;
t=0;
display(sec1,sec2);
}
}
stop_pin = 1;
s = sec1;
t = sec2;

while ( start_pin != 0 && reset_pin != 0 ) //Check if start pin or reset pins are not pressed
{
display(sec1,sec2);
}

if (start_pin == 0) //Check if start pin is pressed
{
goto stopwatch;
}
else
{
if (reset_pin == 0 ) //Check if reset pin is pressed
{
s = t = 0;
goto start;
}
}
}
}