luu w jcy oyp wl uxg chs ehs vs gsa . That may seem like gibberish and indeed it is! It’s actually 20 random characters generated by the computer (here try it out yourself). Electrical random number generation is used in things like gambling, statistical sampling, computer simulation, games, and cryptography.

However most electronics cannot produce true random numbers and instead rely on pseudorandom number generation. A pseudorandom number generator is simply a mathematical formula for producing a sequence of numbers based on a set of initial values. These values only appear random. To improve their randomness, many electrical systems incorporate readings from the physical world such as voltage measurements and keystrokes as there initial set of values. Indeed, the best random number generators take their input directly from the physical world such as this number generator that takes in readings from atmospheric noise.

What if we want to include randomness in the design of a circuit or digital musical composition? The design of a circuit that produces pseudo random numbers is difficult. The easiest way would be to measure some random physical phenomenon. Any kind of sensor that reads outside noise can be used for this purpose.

In fact the Sparkle Labs Discover Electronics Kit has everything you need.

(UPDATED SCHEMATIC)

In this case the sensor will be the simple switch. In this schematic, we have created a circuit that oscillates voltage between two LEDS. The “noise” we are using is the time between button pushes. The oscillation occurs so quickly that it is imperceivable to the human eye. The outcome of the button push is random since a human cannot time her/his button pushes. Thus when the switch is hit one of the LEDs will randomly light up. The use of high oscillation frequencies is often applied for randomness generation. This popular electionics magazine article even employs the method for use in an electronic six-sided die.

Luke BrownGold || In: Projects | | permilink