Bartosz Tomeczko varia

LED Christmas tree

I would like to present to you my LED Christmas tree. Very simple construction: Attiny2313 + 10 0805 resistors and 10 SMD LEDs.

 

 


Though Christmas 2012 have already passed, I would like to show you my LED Christmas tree;)

Whole construction is quite simple and contains only one MCU (Attiny2313), ten SMD leds and ten 0805 SMD resistors. So, as you can see, this is a SMD Christmas tree.

How those LEDs behave? Random? Pseudorandom?
Those ten LEDs blink utilizing PWM technique in a manner quite similar to (sin(x)+1)/2. Now try to imagine 10 points on this graph (between 0 and 2*pi). Values at those ten points are PWM values for every LED. And (during time) x is changed. That's how it works in short words.

Here you can see how it works:

Short look at construction is available here:

DSC_0702.JPGDSC_0695.JPGDSC_0700.JPGDSC_0696.JPGDSC_0698.JPGDSC_0701.JPGDSC_0699.JPGDSC_0697.JPG

Circuit and layout
Circuit and layout will also be available in near future;)

Source code and binary
Those will also be available later.

 


AdmirorGallery 4.5.0, author/s Vasiljevski & Kekeljevic.