Well, after 3 winters, finally giving up on the outdoor Christmas lights.

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(allanGEE) #1

Well, after 3 winters, finally giving up on the outdoor Christmas lights. FastLED worked flawlessly and easily, but the cheap WS2812B’s couldn’t hold up to a climate with up to +40 Celsius in summer to as low as -40 Celsius in winter. And I can’t justify the cost of 50 meters of high quality LEDs just for seasonal lights.

Have to say though, it was a lot of fun working on the project, and learned a lot, so no regrets.

Couple of questions.

I’d like to re-purpose all the cheap WS2812B’s for indoor projects. Some of those would be far more compact if I took the LED component off the strip.
1) Can the LEDs work properly without the little surface mount resistors that are also on the strip?
2) Has anyone removed the LEDs from the strips “en masse” succesfully? I’m going to try a heatgun on the BACK side of the strip (to avoid melting any plastic), but wondering if anyone has tried anything else.

Thanks again for all the support and answers I received during the outdoor light project. I want to emphasize again – FastLED and the FastLED community were/are awesome! It was the cheapskate (me) buying the components that was the problem. :slight_smile:

(Jeremy Spencer) #2

You’ll find out almost impossible to remove the LEDs and resolder them onto a new board without damaging them. Worth a try though :wink:

(JP Roy) #3

Hi Allen, I would agree with @Jeremy_Spencer . I have not tried to completely strip a strip (uhh…) of its ws2812b devices but tried to just replace a few leds and it was a real pain as I did not have to right tools. I only have an old but very functional 60W pencil type soldering iron. You would need a real surface mount desoldering tool I guess.

Re-soldering them is another big problem, where/how would you resolder them ??

As for that resistor, all my strips are 10mm wide and 60 LEDs / meter and they do not have them. The ws2812b datasheet I have from worldsemi does not even have them resistor in their ‘typical application circuit’ drawing either. Unless you have the older ws2812 with 6 pins per device or you have a 12V strip variety (never used them so I do not know but guess a resistor may be necessary there). That resistor if it Is used between data-out of one device to data-in of another, I think you can do without it.

Care to detail how you plan to re-use those ws2812b devices exactly ?

(pheoxs) #4

SK6812’s can be had for like 4 cents a piece so I don’t think it’d be worth trying to strip the strips. Also those aren’t resistors on the strip, they’re capacitors.

(allanGEE) #5

@JP_Roy to sure what I would use them for. Possibly a grid layout of some sort? Just thought that popping them off the strip would let me arrange them tighter than the 150/meter spacing on the strip. I’m sure I can find a lot of things to do with them still on the strip… just exploring options.

SEMI-RELATED UPDATE: Don’t buy the GE Color Effects G-28 Christmas lights as a temporary replacement or fix for outdoor lights. The box says you can connect up to 7 strings. What it doesn’t tell you is that the strings don’t synchronize (no shared data line). I’ll be in the return line at Costco this week. :slight_smile:

(JP Roy) #6

@allanGEE I’m guessing you meant 30/meter strips or 150/5meter. They would be great for outside where people look from a distance as opposed to something inside and smaller where that amount of pixel spacing could be too much indeed !

I have tried with fresh (not previously soldered ) WS2812b devices in the tightest flat 2D grid possible where the DO (data-out) pin of a device would actually contact the DI (Data-in) of the adjacent device. Any number of devices could be daisy chained like that diagonally forming a straight line.

To form a 2D matrix you would create another diagonal device line like above but reverse it’s direction such that you have the VCC pads physically contacting AND the GND pads physically contacting. ETC…ETC… That would be the absolute tightest grid you can achieve with the WS2812b and creates a pitch of 5,4mm between devices.

Sounds nice in theory but actually assembling that thing was impossible (at least to me… :wink:

(Mr Happy) #7

what kind of strips are you using? I’ve been using the cheap silicone jacketed ws8211 outsid inside of aluminum channel for about two years with zero issues as a permanent installation. I think there might be something wrong with your setup causing high current in rush or ground loops destroying your leds.

(allanGEE) #8

@Mr_Happy WS2812B’s. Prior to the first installation outdoors, I had a big chunk of the system running for about a month in the basement. No issues. Caps are in place to help with any surges or drops – which there probably aren’t since I have frequent power connections – and ground loops were carefully avoided.

No problems until the temperature dips. My best guess is faulty or bare minimum assembly procedures that weaken until breaking with contraction/expansion. I bought the cheapest I could find on eBay (which always come with the possibility of buying from someone who bought “seconds” or rejected product to re-sell).

Could very well be that if I bought from a reputable source that the problems would be eliminated – but after all this time I have new LED squirrels to chase.