Randomizer help

[zhewitt]

I am building a circuit that requires 4 inputs to be randomly set either high or low. I do not know how to make these inputs set low or high randomly and I don't want to use a microprocessor. Any help would be much appreciated

 

[Martaine2005]

I am building a circuit that requires 4 inputs to be randomly set either high or low.

That's nice.. So it goes on and off then?

I do not know how to make these inputs set low or high randomly and I don't want to use a microprocessor

How are you going to build it then?
What ideas have you got?
What research have you done?

Martin

 

[zhewitt]

I am currently just trying to have it randomize once, not repeatedly. The four inputs are actually the inputs on a bcd to decimal decoder. The research I have done is next to none, because every time I look up my issue I get results for mine craft.

 

[Martaine2005]

Lol, minecraft is a bugger!!!
Have you researched this?

Martin

 

[zhewitt]

yes that is the website I am using for wiring the bcd, my problem is not which imputs to attach to, but how to randomly make those inputs go from high to low or from low to high.

 

[GPG]

https://en.wikipedia.org/wiki/Hardware_random_number_generator

 

[Martaine2005]

You could also look up some 555 and 4017 random generators. Dice circuits for example.
Just a thought..

Martin

 

[zhewitt]

Ok thanks

 

[BobK]

I am currently just trying to have it randomize once, not repeatedly. The four inputs are actually the inputs on a bcd to decimal decoder. The research I have done is next to none, because every time I look up my issue I get results for mine craft.

If you just want it to randomize once, use a get a random number from a website (yes, they are out there), convert it to binary and use the low 4 bits to hardwire the 4 inputs.

However, I cannot see how that could possibly be of any use.

Perhaps you mean that you want it to randomize each time power is supplied?

Edit: Here is a link to a random number generator. Just entre 0 for the lower bound and 15 for the upper bound and get your one time random number:

https://www.random.org/

Bob

 

[zhewitt]

Yes that is what I mean I want it to randomize each time power is supplied

 

[BobK]

Okay, that is a little more reasonable.

But not such a simple problem.

The easiest way I can think of would be to have a counter running all the time, even when power is off and then clock in into a latch on power up. But that requires use of some power all the time.

Another thing you could try is powering a high frequency oscillator, maybe 1MHz and, on power up use a 555 in monostable mode to capture the count after a short delay. Hopefully, the variations in the delay would be enough to make the number look random.

Or, I think there are actually true random number modules that you can buy, but this might be a little costly.

Bob

 

[AnalogKid]

What is the maximum allowed time delay between power-on and the decoded decimal output being stable? Also, are the outputs allowed to change or bounce around before he stable output, even for just a few microseconds, or do they have to snap to the stable output?

ak

 

[CDRIVE]

This is a really low grade (musings) solution but an exceedingly unstable osc. should work. I built quite a few of those!

BTW, I love your Big Boy! It was the Alpha Male fire breathing Dragon of the rails!

Chris