How to generate pseudo random numbers on 8-bit micor?

[electrojit]

I want to gerate random number without using any inbuilt functions, so please tell me any simple algorithm if possible as early as possible.

Thank you in advance!

 

[jocom]

ey,
i think u can get some useful stuff from
h**p://en.wikipedia.org/wiki/PRNG
but each PRNG will repeat itself after a undefined number of iterations
it depends on your algorithm how many iterations are acceptable
i donno where u wanna use it for. but if it isnt allowed to repeat itself within a few million iterations u gotta write a good algorithm. if ur fine with repetence in 100 iterations u can use simpler algorithms

jocom

 

[SuperUser]

https://www.pjrc.com/tech/8051/rand.html

 

[IanP]

Try this one:
**broken link removed**

Regards,
IanP

 

[white_shadow]

There is no truly random number. In addition since you don't want to use a built in function such as RAND(), I suggest you write your own. It can be rather simple such as taking an argument such as my_rand(x) = x + 1. In addition you can seed your random number with a clock, a method in which RAND() is used, such as implement my_rand(clock + 1).

 

[jocom]

There is no truly random number.

I do not agree. There are methods to get real random numbers. Though not with an algorithm. An example:
The time between the decay of Krypton-atoms. Measure it and u got a random number.
There are installations that produce random-numbers this way.
jocom

 

[rfguy1]

I have generated Pseudo Noise using a PIC 12c672 .Basically is having arrays . You can tap the array and exor it with a value. The sequence will repeat atfer some time, but looking it into an spectrum analizer it was enough for my purposes (apply this noise to a laser) .

 

[x_zoli]

Hi,

you can obtain a true random number using the noise of a zener diode. Just bias the zener using a resistor and amplify the AC component of the signal then compare it with a treshold voltage to obtain the logic value.

Best Regards