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Wishing You a Very Random Christmas

  • Writer: Dan Koellen AI6XG
    Dan Koellen AI6XG
  • Nov 23, 2020
  • 1 min read

Being the holiday season I decided to post this article from the December 2014 issue of Nuts & Volts magazine www.nutsvolts.com that I wrote about an outdoor Christmas Tree display I built and erect every holiday season. I had built an outdoor tree of light strings in a tree formation but was not pleased with the static display. So I built a microcontroller control box that will change the display in a random manner. At each power up, the seed for the random number generator is changed so that patterns are different for each operation.


I have posted here the article for your viewing pleasure and the C source code in GitHub. From the article and source code you can build your own version. The C program was used with an old compiler so if you compile with the current Microchip 8 bit compiler there will be errors thrown but they should be easily resolved. I also have posted here the original photos used for the article with an additional video of the 'Christmas Tree' in operation.





Eight channel light controller schematic

A view of the solid state relay (SSR) board
The microcontroller circuitry is built on a perf board

The microcontroller board mated to the SSR board


A close up view of the AC wiring

The completed assembly before installing the cover

The right figure is a drawing of the 'tree' as viewed from the top, eight sets of LED lights result in 16 legs.

The left figure is a drawing of the side view of the 'tree'. The legs are the LED light strings meeting at

the top of an 8' metal pole.




2 comentários


SCelesteaAggiea
30 de mai.

Looking down at this watch, you see so many shapes. There's a round bezel over an octagonal frame. Then the case itself is octagonal, but sort of built into a square platform. So link it sits on the wrist as link a square, but it is not a square watch. It's an octagonal watch on link a square platform built in thin, delicate layers.

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SCelesteaAggiea
30 de mai.

This marvel is made possible by the caliber MHUB1100.H3. This self-winding movement link delivers a power reserve of link some 42 hours. Each piece is complemented by a black rubber and calfskin strap featuring printed colored link stripes.

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