Neopixel christmas lights

What are you developing?
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zoomx
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Re: Neopixel christmas lights

Post by zoomx » Wed Jan 11, 2017 10:44 am

racemaniac wrote: Also, not sure if it's mentioned on this forum already, but neopixels actually need about 3.7-3.8V to fully turn on all colors. Above that voltage you don't see any difference. The rest is just dissipated as heat by the voltage control on the pixel.
:shock:
Never heard about this.
The Adafuit PDF Datasheet
https://cdn-shop.adafruit.com/datasheets/WS2812.pdf
says 6-7V (instead of 5!!!)
but this one
https://www.parallax.com/sites/default/ ... asheet.pdf
says +3.5~+5.3
but they are different chips so your're right for WS2812B, the first one is WS2812 without B.
Reading here
https://acrobotic.com/datasheets/WS2812B_VS_WS2812.pdf
WS2812 has four pins instead WS2812B has six pins so you can distinguish them. I believe that I have only WS2812B but I have to check.

I like very much these LEDs!

racemaniac
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Re: Neopixel christmas lights

Post by racemaniac » Wed Jan 11, 2017 10:57 am

zoomx wrote:
racemaniac wrote: Also, not sure if it's mentioned on this forum already, but neopixels actually need about 3.7-3.8V to fully turn on all colors. Above that voltage you don't see any difference. The rest is just dissipated as heat by the voltage control on the pixel.
:shock:
Never heard about this.
The Adafuit PDF Datasheet
https://cdn-shop.adafruit.com/datasheets/WS2812.pdf
says 6-7V (instead of 5!!!)
but this one
https://www.parallax.com/sites/default/ ... asheet.pdf
says +3.5~+5.3
but they are different chips so your're right for WS2812B, the first one is WS2812 without B.
Reading here
https://acrobotic.com/datasheets/WS2812B_VS_WS2812.pdf
WS2812 has four pins instead WS2812B has six pins so you can distinguish them. I believe that I have only WS2812B but I have to check.

I like very much these LEDs!
I also only ahve ws2812B, i indeed can't be sure how the others respond. the 2812b is also what you find most these days.

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RogerClark
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Re: Neopixel christmas lights

Post by RogerClark » Wed Jan 11, 2017 7:26 pm

Looking on the AliExpress listings, its hard to be sure which driver IC they are using.

Some vendors list both the B and non B versions in the description. I doubt they know what device is on the items they are selling, even if they list a specific IC.

I presume they all work in the same way, i.e as a bit shift register

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Rick Kimball
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Re: Neopixel christmas lights

Post by Rick Kimball » Wed Jan 11, 2017 7:44 pm

racemaniac wrote:I may be a bit late for this, but for the season i programmed some nice neopixel patterns to use as christmas lights :)...
Did you post the stm32 code you are using and I missed it?
-rick

racemaniac
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Re: Neopixel christmas lights

Post by racemaniac » Wed Jan 11, 2017 8:04 pm

Rick Kimball wrote:
racemaniac wrote:I may be a bit late for this, but for the season i programmed some nice neopixel patterns to use as christmas lights :)...
Did you post the stm32 code you are using and I missed it?
haven't posted it yet
If you want to use it, here it is: http://users.telenet.be/racemaniac/Neopixel%20Xmas.zip
I hope it'll just work, i've used my spi dma library in it (since i'm now used to it). I don't think it relies on changes i made to the core locally, but not entirely sure.
If it doesn't work, just replace the SPI part :). I'm using the MOSI of SPI1 to generate the neopixel signal :). encoding 1 neopixel bit to 3 spi bits :).

And there's probably a bit of dutch here and there in the file :). It was a request of the girlfriend, and we also worked a bit on it together (learning here some programming & electronics basic ^^).

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Rick Kimball
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Re: Neopixel christmas lights

Post by Rick Kimball » Wed Jan 11, 2017 8:24 pm

thanks!
-rick

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zoomx
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Location: Mt.Etna, Italy

Re: Neopixel christmas lights

Post by zoomx » Thu Jan 12, 2017 8:46 am

RogerClark wrote:Looking on the AliExpress listings, its hard to be sure which driver IC they are using.
I believe that if the power source is rated as 5V they sell the B version. Maybe the older version is not selled any more or is difficult to find. But there is still a possibility so we have to check the power voltage.

@racemaniac,
thanks for sharing!

racemaniac
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Re: Neopixel christmas lights

Post by racemaniac » Mon Jan 16, 2017 5:42 pm

Ok, after an appeal the video is back on youtube XD

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