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Can Timer0 use for random number generator?

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gordon the light

gordon the light

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Hi, Sorry if I posted in the wrong thread.

I tried to use Timer0 to generate 2 random numbers, using PIC18f4520 and c18 compiler in c language. But is not working. Please help me.

Here is my program. 

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#include<p18f4520.h>
#include <stdlib.h>
    
void ISR (void); 
char i,start; 
 
#pragma code L_vector=0x18void L_vector(void){_asm goto ISR _endasm} 
 
#pragma code#pragma interruptlow ISR 
void ISR(void) 
{if(INTCONbits.TMR0IF){ 
TMR0H=0xC2;TMR0L=0xF7;i=rand();start=(i+TMR0H)%8;j=rand();end=(j+TMR0L)%8;}} 
 
void main(void){ 
 
 INTCONbits.GIEH=0;RCONbits.IPEN=1;INTCON2bits.TMR0IP=0;TMR0H=0xC2;TMR0L=0xF7;T0CON=0b100000101;INTCON=0b11100000;
 
 
while(1);}
 
Last edited by a moderator:

Possibly, but the number may be cyclic because the timer will update at a regular rate and will always have the same start value. In other words, you may get something which looks random but gives the same pattern sequence after each processor reset. If you are finding a truly random sequence I would suspect it is because 'i' and 'start' are not initialized.

What is it actually producing?

Brian.
 

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