{"id":1568,"date":"2015-01-08T00:37:02","date_gmt":"2015-01-07T23:37:02","guid":{"rendered":"http:\/\/majek.mamy.to\/?p=1568"},"modified":"2015-02-09T01:07:49","modified_gmt":"2015-02-09T00:07:49","slug":"christmas-tree-lamps-with-arduino-and-ws2811-leds","status":"publish","type":"post","link":"https:\/\/majek.sh\/en\/christmas-tree-lamps-with-arduino-and-ws2811-leds\/","title":{"rendered":"Christmas tree lamps with Arduino and WS2811 leds :-)"},"content":{"rendered":"

Somewhere at the beginning of November I discovered RGB LEDs with embedded controller: WS2812 and others. Idea was so cool for me that I had to own one to play with it \ud83d\ude42
\nThese chips became so common, that there are even put inside LEDs, like on this WS2812 diode:<\/p>\n

\"WS2812<\/a><\/p>\n

Considering time of the year, it was obvious to me to make whole string of lamps for Christmas tree. Then I found on Aliexpress ready made chains of such LEDs. \ud83d\ude42
\nSo, my LEDs aren’t with chips inside, but with small PCBs sealed with some kind of hard silicone – maybe not so elegant as chip integrated inside LED, but cheaper – which counts if you buy 50 of them :-):<\/p>\n

\"WS2811<\/a><\/p>\n

Day before Christmas I still haven’t done anything with these light, so it was last chance to do something useful with it.<\/p>\n

Connecting everything was quite easy as there are only 3 components: 5V power supply, Arduino Pro Mini board and LED chain.<\/p>\n

Programming protocol for WS2811 was more challenging – generated waveform must be very accurate, with some time intervals taking only 8 cpu Atmega328 clocks (at 16MHz). So, I chose assembler to do it (as usual \ud83d\ude42 ).
\nTo be more hardcore, it was 3am when I started debugging \ud83d\ude42 Honestly, without my new oscilloscope, finding these 3 mistakes I’ve made, could’ve took hours. Especially that Chinese guy who sells these LEDs described them as ‘we sent WS2811. Or we may sent UCS1903’<\/em> – two different possible chips (!) with two different protocols and no one knows which version I’ve got.
\nLuckily for me. it was WS2811, so first guess and code worked.<\/p>\n

I added few simple routines to move light across whole chain of LEDs and put everything on Christmas tree.<\/p>\n

All code for this ‘one night project’ you could find on my Github page: https:\/\/github.com\/majekw\/wsled<\/a><\/p>\n

This is how it looks like on my Christmas tree:
\n