Seven Step Sequencer


Using a LED/LDR pair to form inverting Photonic logic gates. The entire Boolean logic set handled by resistors and diodes! Who'd'a thunk

Dr. CockroachDr. Cockroach 08/03/2019 at 23:493 Comments

The three phase Astable is now a seven step sequencer. When wired in order 1,2,3,4,5,6,7 the firing order is 1,6,4,2,7,5,3 then returns to 1 so it steps by 5. The sequence does repeat. This can be the sequencer and clock combined for IO2 the Inside Out Light Logic computer. No other clock will be needed.

Here is a good display of the sequencer in action and I realized that I now have a solid clock and sequencer in a single circuit. This will be used for the Light Logic computer project this winter.

I ran out of ideas other than adding a starter switch to the panel. On power up the loop freezes so I have to ground one input in order to unbalance the loop. Then I got the scope out and then the music fits the display.

That is a trace of cell one followed by cell six.

After I looked at the output traces, I wanted to see if I could sharpen them up a bit. so I added a Light Logic non-inverting buffer gate to the output of cell number one and the next video clip shows a big improvement. The lower trace is output number one and the top trace is the same output run through the buffer.


Dr. Cockroach wrote 08/04/2019 at 17:33 point

I can try to filter the output a bit but no transistors in keeping with the whole idea of Light Logic. Yes, glowing wires would be cool and I did think about trying to use fiber optics in a design someday :-)

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Xasin wrote 08/04/2019 at 17:11 point

Looking good! 
The clock looks a bit like it's not very symmetrical, which at these speeds won't matter, but ... What about the overlap between signals?
I could imagine it might be a problem to have the CPU try and do two things at once because the clock outputs were simultaneously on. Though a small filter to get cleaner pulses should help.

Apart from that - this is REALLY reminiscent of the good 'ol days of Redstone Torch logic in Minecraft. Too bad the wires don't glow when they're on, but the LEDs are pretty close!

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Dr. Cockroach wrote 08/04/2019 at 17:27 point

I scoped out the 7 outputs and believe it or not, no overlap as of this morning. If there ends up being...There is the issue of the tolerance of the caps and CdS cells so each led might flash a bit longer or shorter but they each key the next so should not be a problem at the speeds I expect :-)

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