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switch for display a number 1,2,3 in lcd display

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suga

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hi

how to display 1,2,3 by pressing a only one switch.1st I press a switch 1 has to come.for 2 presses 2 has to come.for 3 presses 3 has to come.for display am using Lcd.
 

create a timer and check the number of press events in a particular time...

------------or------------simply
1.detect the button press by high or low level using if condition
2.wait & continiouly check press event like below and display


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if (BUTTON1 == PRESSED) 
{
char press = press + 1;  
 
 
for (i=0;i>=10;i++) 
{
delay_ms(100);
press = press + 1;    
};
 
display lcd (press);
 
};




this programme will display number of presses of button .

---------- Post added at 12:29 ---------- Previous post was at 12:27 ----------

you can modify this programme according to your compiler and micro but concept will be the same.
 
Last edited by a moderator:
thank u.please explain timer concept also..

---------- Post added at 08:20 ---------- Previous post was at 08:19 ----------

am using 8051 micro controller,keil compiler
 

you can start and stop any timer by programme in any micro.

1.start a timer when a button is pressed and increment a --- 




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if (BUTTON1 == PRESSED) 
{ 
 
// always increment this variable when button is pressed
press = press + 1;
    
 
// start timer for 1 seconed --- after one second it will fire its interrupt survice routine 
 
if (g==0) {startimer; g=2;};// now g will be zero only in timer interrupt
 
};
 
 
 
 
 
// Timer 0 overflow interrupt service routine
interrupt [TIM0_OVF] void timer0_ovf_isr(void)
{
// after one second programm will be here and now first display no. of presses of button in one second
diplay LCD (press); 
 
 
// refresh all varaible for next work
g=0;
stop timer; 
 
}




2.fire a timer interrupt in a certain time defined by u .
for example --
 
Last edited by a moderator:
am using keil software.micro controller 8051
 

Code: 
#include<reg51.h>
//LCD pins initialization
sbit button=P2^0;
void main()
{
count=0;
while(1)
{
  if (button==0)
{
   count++;
lcd_data(count+48);
while(button==0);
}

}


you add the LCD commands and data functions.


Hope This may help
 
if pressed the switch or button it will give low pulse when it gives count will b incremented and wait till the key is released .
when u released it will wait till the next time key is pressed. if u pressed again the count will b incremented by 1 i.e.2 ..like this it will go on..
You have to display the count value on lcd with adding 48 to it(To make it Ascii)
 

Hi...
This is my program...when I press the button one time 'a' has to display.when I press the same button 2 times 'b' has to display.same button is pressed 3 times 'c' has to display.its like a mobile keys.here am using 4x4 keypad and for display am using lcd.output is not coming 


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#include<reg51.h>
#define p0 P0
#define p2 P2    
sbit c1=P2^4;
sbit c2=P2^5;
sbit c3=P2^6;
sbit c4=P2^7;
sbit r1=P2^0;
sbit r2=P2^1;
sbit r3=P2^2;
sbit r4=P2^3;
 
sfr c=0x90;
sbit rs=P3^7;
sbit rw=P3^6;
sbit en=P3^5;
unsigned char position=128,i=0;
int check_again[10]={0,0,0,0,0,0,0,0,0,0};
void lcd();
void keypad();
void num_check(int a,int b) ;
 
void lcd_d( char val);
void lcd_in( char val);
 
 
 
void wait(int j)
{
long int i;
for(i=0;i<j;i++);
}
 
void lcd_in(unsigned char val)
{
c=val;
rs= 0;
rw=0;
en=1;
wait(10);
en=0;
return;
}
 
void lcd_d(unsigned char val)
{
lcd_in(0x0f);
wait(10);
c= val;
rs= 1;
rw=0;
en=1;
wait(10);
en=0;
return;
}
 
void num_check(int a,int b)  //Check function
{
int j;
for(j=0;j<10;j++)
{
   if(j!=a)
  {
   check_again[j]=0;
  }
}
if(check_again[a]==3)
check_again[a]=0;
check_again[11]=1;
check_again[12]=1;
}
 
void display(int a,int b) // Display function
{
switch(b)
{
case 1:
{
    switch(a)
        {
             case 1:{
                if(check_again[a]>1)
                i--;
                lcd_in(position+i);
                lcd_d('a');
                wait(5000);
                 // num_check(1 ,check_again[1]);
                break;
                    }
}         }
case 2:
{
     switch(a)
     {
         
            case 1:{
                if(check_again[a]>1)
                i--;
                lcd_in(position+i);
                lcd_d('b');
                 wait(5000);
                // num_check(1 ,check_again[1]);
                break;
                    }
        }
}
case 3:
{
     switch(a)
     {
         
            case 1:{
                if(check_again[a]>1)
                i--;
                lcd_in(position+i);
                lcd_d('c');
                 wait(5000);
                // num_check(1 ,check_again[1]);
                break;
                    }
        }
}
}
}
void keypad()
{
if (c4=0,c2=c3=c1=1,r4==0)
{
p0=0xf0;
display(1);
lcd_in(0x0c);
}
}
void main()
{
p2=0x0f;
lcd();
 
while(1)
{
p0=0xfe;
keypad();
 
 
wait(5000);
//p0=0xfd;
//keypad();
 
 
//wait(5000);
 
//p0=0xfb;
//keypad();
 
//wait(5000);
//p0=0xf7;
//keypad();
 
//wait(5000);
 
}
}
void lcd()
{
lcd_in(0x38);
wait(250);
lcd_in(0x0e);
wait(250);
lcd_in(0x01);
wait(250);
lcd_in(0x06);
wait(250);
lcd_in(0x86);
wait(250);
lcd_in(0x80);
wait(250);
}


---------- Post added at 08:34 ---------- Previous post was at 08:08 ----------

Now I understood ur coding.why we have to add 48
 
Last edited by a moderator:
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