Help me

[Hung]

Hi there.

 I want to design the project IR  .

That is mean inftrared data transmisstion with the PIC microcontrller.

 so i saw some projects  and i saw the code, but i dont understand 

 

the  value of clock . i mean how many. the value of Crystal . 3Mhz, 4Mhz….so on. please help me.

 

 the code:

#include<p18f452.h>

#pragma config OSC=HSPLL, WDT=OFF,BOR=OFF,PWRT=ON

voidputch(char byte)

{

while (!PIR1bits.TXIF);

TXREG = byte;

}

chargetch(void)

{

while (!PIR1bits.RCIF);

return RCREG;

}

voidwait800us(void)

{

int x = 610;

while(x–);

}

voidmain(void)

{

//initializevariables

charinput, whichBit,temp, total;

//initializeserial registers

TXSTAbits.TXEN = 1;

RCSTAbits.SPEN = 1;

RCSTAbits.CREN = 1;

SPBRG = 0x40;

//Setup PORTB

INTCON2bits.RBPU= 0;

TRISB = 0x0F;

PORTB = 0;

//Setup Timer2

T2CON = 0x79; //PRE= 4 POST= 16

PR2 = 187;

putch(‘R’);

putch(‘x’);

putch(0x0D);

putch(0x0A);

while(1)

{

while(!PORTBbits.RB0);

T2CONbits.TMR2ON= 1;

whichBit= 0;

total= 0;

while(whichBit<

{

while(!PIR1bits.TMR2IF);

PR2 = 125;

PIR1bits.TMR2IF= 0;

if(PORTBbits.RB0== 0)

{

temp= 1 << whichBit;

total += temp;

}

whichBit++;

}

putch(total);

T2CONbits.TMR2ON= 0;

PR2 = 187;

}

}

[AJISH ALFRED]

Hi Hung,

The code is written for a particular hardware. Unless you post the circuit diagram or block diagram it would be difficult for some one to help you with it.

[Hung]

 

this is circuit. please help me. i simulated in the proteus but it did not work. so i think that i dont know  exactly the the  value of clock . 

 

please answer me as soon as possible.

 

 

 

 

wysiwyg_imageupload:9424:

[AJISH ALFRED]

Hi Hung,

You can use 4Mhz crystal. Try to do real hardware other than wasting your time in a simulation software, especially when you are doing wireless data transmission circuits.

[Hung]

Thank you so much. thanks for your help. 

[AJISH ALFRED]

You are welcome Hung. Please feel free to post your further queries.

[Author]

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