numbers using floating voltages

Special_K

Looking for a program I have seen before. It was code for the BS 2 that was a random number generator, it used the floating voltages of the unused pins to and a more (truer) random number response.

Tracy Allen

You can tie an RC circuit to the pin, and use the RCTIME command. The least significant bits will be somewhat random and can be used to add real randomness to the Stamp's RANDOM operator. The bits are most random when the time constant is long and when you use poor components and expecially if you use poor wiring practices, Say, loop a long wire around and around, so that it will pick up AC hum and switching noise that adds to the capacitor voltage.

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Tracy Allen
www.emesystems.com

Special_K

Do you have a link to this circuit or code.

Tracy Allen

Special_K said...
Do you have a link to this circuit or code.

It is just an RC circuit, like this one attached that has a time contant of RC=.1 second. The values are not critical so long as they have an RC value between 10 milliseconds and the RCtime maximum. The wiring is shown as curves to indicate that you should do it with long wires, wrapped around the edge of your circuit board & CPU for example. You could also include something like a reverse biased LED (cathode to the pin, p0 and anode to Vss) and that would make the circuit light sensitive as well. Here is code:

chance_pin Pin 0
lottery VAR word
result VAR word

DO
   HIGH chance_pin
   RCTIME chance_pin, 1, result
   RANDOM lottery   ' psuedorandom
   lottery=lottery+result   ' plus real radomizer
   DEBUG DEC lottery
LOOP

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Tracy Allen
www.emesystems.com