Random 8+ LED Flasher

How about eight 555 timer circuits. :P D from BC

Nah, you can get by with half that, just add glue logic (AND, OR, XOR, etc. combinations) to make different patterns.

I've made some "Blinkenlites" using a 74LS168(?) serial-in, parallel-out, 8 bit shift register and a quad XOR gate, wired as a pseudorandom number generator. The light pattern cascades to the right, but that isn't as noticable when you spread them out and break up the movement. There are 255 combinations, so it's got a pretty long repeat for being two chips and a clock (555, let's say ;).

Tim

-- Deep Fryer: A very philos>

I'm familiar with that technique. (MLS generator...maximum length sequence) Basically an out of order binary counter. I read an article years ago about someone who wrote a computer program just to "search" for logic tapping locations for various register lengths to produce all combinations. Improper logic results in not producing all combinations (a shorter sequence). The program had a long run time. I guess he wasn't able to do the math which I think was so intense that it was quicker to run a "hit and miss" type program. D from BC

D from BC wrote in news: snipped-for-privacy@4ax.com:

Or a micro (circuit easy, coding required)

And best of all, highly modifiable. And this application sound like one that will take many iterations to get the desired random flashing effect. Much easier to do that in code.

Don Lancaster has circuits up to, I think, 31 bits in his TTL cookbook - I wonder if he's posted any of them on line?

Don? Are they on your site somewhere? If not, would you put them up? (I lost track of the cookbook several moves ago )-; )

Thanks, Rich

How's he supposed to make book sales if he's posting the goods on here :P I have his Active Filter Cookbook I bought around 1989...One of my favorite books.. He shouldn't be allowed to get old. :) D from BC