Title: {EnTrY} 74xxRNG / Cat Toy
Post by: t0mpr1c3 on October 15, 2012, 05:16:42 am
Post by: t0mpr1c3 on October 15, 2012, 05:16:42 am
I made a true random number generator using just a shift register and a hex inverter -- and what would ordinarily be a few design no-no's. The idea was to induce oscillation in the shift register by clocking it with a very slow rise time. Leaving off the bypass caps helped make it even more vulnerable to supply line noise.
I wouldn't use this RNG for choosing lottery winners, but it was good enough to make a daft cat toy with the addition of a servo-mounted laser pointer and one additional logic chip.
http://www.youtube.com/watch?v=ykJssSpndnU (http://www.youtube.com/watch?v=ykJssSpndnU)
Much more detail at http://smokedprojects.blogspot.com/2012 ... t-toy.html (http://smokedprojects.blogspot.com/2012/10/hacky-random-number-generator-cat-toy.html)
I wouldn't use this RNG for choosing lottery winners, but it was good enough to make a daft cat toy with the addition of a servo-mounted laser pointer and one additional logic chip.
http://www.youtube.com/watch?v=ykJssSpndnU (http://www.youtube.com/watch?v=ykJssSpndnU)
Much more detail at http://smokedprojects.blogspot.com/2012 ... t-toy.html (http://smokedprojects.blogspot.com/2012/10/hacky-random-number-generator-cat-toy.html)