Currently (and for the next few weeks), I don’t have access to my gears… So to occupy myself a bit I try to design new modules.
For one of them, I need a random source of bits, and I found this circuit (upper part):
Did any of you ever tried this one (or has a better alternative)? It’s quite difficult to simulate randomness…
Also, what are your thoughts on the oscillator circuit? I tried to simulate it too, but no success. I don’t know if it’s from the circuit itself or because the simulator just can’t…
Oh I hadn’t thought about that! But it seems that I would get a biased value, no? (I really don’t know, true random is hard!)
I don’t have much space left, so the circuit should have a small footprint. But yeah actually, just a clocked ADC and no need for the sample and hold, that could fit!
Not really, unless you want to go the quantum randomness level (like a Geiger Counter), this will probably suffice.
When you add the clock and adc this shouldnt add much.
This design is a hardware random number generator, it uses stochastic processes that are unpredictable, and generally considered random.
Other ways include using a transducer to convert physical phenomena into an electrical signal (like a sensor), then using an amplifier to raise the amplitude of those fluctuations to a measurable level. You could prolly do this with a moisture sensor or LDR and it would work fine.
The only time i would recommend a software solution is if its easier (already using a microcontroller) or if you need to be able to use seeds (looks like the link you provided does implement seeds, so you wont be able to do that here).
You could use the innards of a smoke detector to give you some radioactive decay. I’m not mad enough to want to do that though. I’d look for a decent PRNG implemented on AVR (the 8-bit chip they use for Arduino.) It should be easily good enough for synth. The well named ATtiny85 chip has 8 legs and can run on a low voltage source and will spit out randomish numbers until the crack of doom.
After making this module I found out that David Cockerell and Peter Zinovieff had pretty much done the same thing sometime around 1965. They were generating random voltages for musical purposes using a geiger counter and a glowing radioactive wristwatch!
this is getting pretty hard core ! radiation , laser beams and playing with traffic . wait till we start jumping out of planes and dancing on the rims of volcanoes .
