Twinkling Lights using two 556 timers

Thread Starter

mtonge

Joined Apr 19, 2016
92
I did a breadboard of Wendy’s circuit from the schematic provided in Chapter 8: From Four, Twenty (allaboutcircuits.com). I had printed it out and would stare at it periodically trying to figure which LEDs would light and when. Looking at the schematic, the circuit was boggling my mind. There seemed to be a lot of redundant connections. Yesterday I tried to reason it out thinking that, with four timers, there are sixteen possible combinations of on/off states. This didn’t help me at all (mind boggle). I wanted to breadboard this circuit, but wasn’t sure about how to make the connections. I noticed that, other than the four pairs of LEDs connected directly to the timer outputs, there are six pairs interconnected between them. This is just like a fully meshed network I had seen in my Cisco classes ( n(n-1)/2 ). The (incandescent) light in my head came on (must upgrade to LEDs). Still, putting it on a breadboard was a bit of a puzzle. I had to use the resistor values that I have on hand for the R/C timing components, but it works nicely. I liked Wendy’s idea of putting this in a light panel, and had this in mind for a project. At WallyMart I found some translucent, plastic shelf liner with square patterning for the light diffuser. Amazing what you can find when you’re looking for something else.

Here is a link to my YouTube video of the board in action:

P1010500.JPG

TwinklingLights_schem.PNG
 
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Thread Starter

mtonge

Joined Apr 19, 2016
92
Continuing on with the Twinkling Lights project, I completed the proto-board of the breadboard circuit. Soldering 40 wires to the board was not easy (spaghetti fest). I made a moc-up of the light box with the diffuser material.
P1010530.JPG
Here is a link to the light box in action:
 

Thread Starter

mtonge

Joined Apr 19, 2016
92
One Year Later... I have continued working on the Twinkling Lights project, and slowly making progress. I spent some time learning to use Eagle CAD software to design PCBs. I now have my first PCB prototype of Twinkling Lights completed. This version runs 12 Leds using three 555 timers. Take a look at the video.
 
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