1. monkey141

    monkey141 New Elf

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    I was wondering if anyone knows or has tested whether or not the 6803 pixels (mine are from Ray Wu's Store) would still work with either a large gap in between two pixels or a large gap in between the controller and the pixels. I am thinking probably a maximum of 25 feet. The reason I ask is because I am planning on using them in various different places in the yard and I am wondering if I should by a controller for each item or can I just use cables to bridge the gaps.

    Thanks,
    Mike
     
  2. chrisl1976

    chrisl1976 Apprentice Elf

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    we were looking into some 5 meter extensions, but that was about the max between pixels. I'm not sure what the max total length is for the signal wire.
     
  3. dmoore

    dmoore Senior Elf

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    There are clearly a lot of unknowns this year as to what are the outer limits of these devices, their quality and sourcing. Next year should shake out many of these issues. Until then, often the best way is to order some and perform the testing and if possible, post your results so we can all learn.
     
  4. riri7707

    riri7707 Full Time Elf

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    What can i say, from my experience actually on such similar chips:

    Max Length between pixels : 6 meters
    Max length between controllers and first pixel :6/7 meters.

    In general, the more inconvenient is this length between controller and first pixel.
    Means controller needs to be in waterproof cabinet too.

    But between pixels, normally the chip request data/clock in and out. the outputs are boosted and needs in general a resistor in each line (data/clock) for reflexion issues and impedance. Most of the manufacturers don't put these resistors and at end, when you see the show you have failures on sync or not synchronous effects on some pixels randomly.

    The last issue is the power voltage and intensity requested on the string...

    Most of the manufactured pixels will fail after some time, because the PCBs are not build to support so much intensity. so it's necessary to inject power voltage again each xxx part of the string to balance the power and intensity current charge.

    Seems easy, but not so much than that as there are rules to apply and respect; and datasheets are not so good explained than that.

    I learned a lot myself, buying different kind of pixels, making reverse engineering and a lot of breadboard experiences, and i choose one, and impose myself the challenge to develop mine but more robust who can live some years.

    But for sure, this is the future of Christmas lightning.

    Cheers... Henri
     
  5. dmoore

    dmoore Senior Elf

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    I suspect that in the coming years over at places like DIYC, there will be lots more focus on the pixel side than the controller side since everyone's needs are so different (spacing, LED count, physical size, wire guage, etc) and, if what Henri is saying is correct - even quality of electrical design. It looks like Henri is just ahead of the curve this year.
     
  6. OP
    OP
    monkey141

    monkey141 New Elf

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    Thanks guys, I appreciate the help. I ordered two different kinds, the larger 30mm circles and the smaller m5 size. I am not crazy about the quality of either like you have suggested, but I think I am going to give a go at the 30mm circles, and I am trying to plan everything out now. I will be sure to post back with what I end up with. I had started out earlier this year, building my own as well and then abandoned it when I found out about some of these, but clearly the quality (and long term stability) can be questioned.

    Mike
     
  7. dmoore

    dmoore Senior Elf

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    Maybe some enterprising person will make a trip out to Shenzhen, visit with a few factories and have them produce a container or two of these pixels (modules, nodes, strip) and sell them to us with some mark-up....hmmmm... who could that be? I'm sure my 2012 that everyone and their brother will be selling them like they sell 100ct strings of LEDs today.
     
  8. chrisl1976

    chrisl1976 Apprentice Elf

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  9. JonB256

    JonB256 Full Time Elf

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    Henri, you brought up an interesting point about impedence matching. I'm not sure what the desired input or output impedence is for the 6308 chip on the the Data or Clock lines. Adding the right resistance might improve the allowable distance between pixels. The impedence after the last pixel probably isn't of much concern since its Data Out and Clock Out lines don't go anywhere.

    Power injection is an interesting concept, though. I don't have any really long pixel strings to test with, but it seems like if you could make a new 5vdc and Ground connection at every 40th pixel or so, you could go all the way out to 170 pixels without overloading anything. If you did it more often than that, you could use smaller gauge wire. I remember reading that the 42pixel length on 5vdc lines is partially amperage/power related. Power injection fixes that.
     
  10. riri7707

    riri7707 Full Time Elf

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    JohnB256 and dmoore...
    What i can say today, this technology is very new today of course... So many chips and modules from $0.50 to $1.50 makes big trouble in ours minds as Ray always put a new one every 15 days....

    Thanks to Ray, because we will never hear about this simply but maybe by long research over the net...

    Now, we cannot play with 50 modules , but we need more than 400 units to really build someting interesting and our bullet suffers about for sure :-[

    As China offers clones and copy of patented products with new named... Makes somewhere sense to use these clones, even if some "official" sellers, present in our forums claims about patent and duties for Phillips or others brand original names... Buying these devices is legal, or seems legal as customs checks in most of the cases the imports.

    Now this is a real fact, chineese manufacturers is like a poker party: no real serious tests, unfinished products, too cheap to be enough good on time, etc...


    But to manufacture good PCBs, can match if you impose your rules for testing, etc...

    I'm quite lucky as i found a real partner who doesn't want to produce "sheet devices" and helps me a lot on this even for components.

    So going back to the strings, take care because if you'll loose $400 bucks after few moths or only one season can be very crappy...

    So this pixel technology is very new, and thanks to Dmoore, we can benefit of his testing and feedback...

    From my side, i choose WS2801... Why? Simply because my friend in CHINA visit the factory and give me feedback with non documented features, like the possibility to use 3 SMD 5050 without addtional components (not documented on datasheet who limits the current ot 50 ma and 3 SMD consumes 60 ma :); factory provide 10 units for burn tests free... Factory is hearing feedbacks from burn tests.. Somewhere somethnig positive.

    Today i'm looking to avoid the 6 meters lengt from controller to first pixel and ONUMEN technical stuff are also looking for that for their controllers...
    So somewhere is something relevant to have such communication with base...
    The suite : Hope to improve the actual specs of the product...
    I'm quite confident from my side.
    I also take the risk to produce 2000 units (expected 3000), but i want to be on time for this year... Ok, i will have spare PCBs for those who wants to enter in the loop :)
    But for sure, Phil is working hard for the new controller based on this technology and Ed is yet providing devices for multi DMX universe requested by pixel LED modules.
    Now the real war is :wich module protocol, how many LED onboard, lumens per module, LSP or VIXEN compatible, HOW CHEAP IS IT?
    Real Brainstormning
    Cheers...Henri
     
  11. riri7707

    riri7707 Full Time Elf

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    Another point where i can share some experience...
    I'm working as external provider to Eiffel tower where they have more than 230 000 flashing lights (real strobes).
    So the technology is not LED but real discharge bulbs...

    I had the chance to inspect one, and the most important on concept is the quality PCB, electrical wires for time durability and waterproof (here we an go from 40 degrees to - 20°C during the year some times...

    From single Flash Bulb, the most relevant here is the cap (pyramid) reflector who increases the brightness by a factor of 5/6... and the professional case (anti-UV), no humidity, no condensation inside...

    So our pixel LED, needs somewhere to be built for external weather conditions: Australia, US, Europe, Canada, etc... Means to take care about different climatic situation...

    Moon Light... Seems crazy but this light is very dangerous (take a look on outside tables and wood chairs) at end due to this spectral ligths, the enclosures suffers a lot.


    Pixel lights and Pixels controllers as i said is really the future...

    Nobody takes care about $1 per module ( seems cheaper ), but at end : direct to trash after few months of use.
    You just need to read the posts about waterproof failures, 4 wires multicolor, non protected by an envelop, poor quality cooper inside 'you can check: a lot of plastic cable for a very fine conductor wire inside...

    For moment, what can i say: take care before buying pixel LED. Ask for Datasheet, regulations (UV/CE/RUV/RoSh/etc...)

    There is no magical way here, you will always pay for really what you guet.

    After this is your bullet contents...

    Cheers, Henri
     
  12. neilric99

    neilric99 Full Time Elf

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    Henri, one of the issues that hear about here all the time is that the Chinese will label whatever specs they feel is the best, they are not really held accountable to the consequences of not adhereing to what they have printed. So as always, buyer beware when buying from China, unless you have personally been there and verified yourself what you are getting and that you are qualified to inspect against the standards that you require.
     
  13. mrpackethead

    mrpackethead Full Time Elf

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    Im not chinese, but i'm going to stick up for them a little bit. "Some chinese" will label and claim whatever specs they think that you want to hear. I'd suggest that if the same market conditions exisited in the US, Australia or NZ, where no one cared about labelling and claims the same human badness would come out.. They have a differnet set of "rules" and there are people who just take advantage of it.

    The best one i've heard is that "IP" ratings are different in china.. And " it is IP68 as long as you don't' get it wet "..

    However i have to fully aggree with Neil, that you need to spend lots of time ( and money ) in making sure that you get what you need. For me that means going to china multiple times, working in the factory with the chinese, to get the process right, end to end.. I now enjoy a very strong relationship with our factory partner, and we are having very few problems. But it was no easy road.
     
  14. OP
    OP
    monkey141

    monkey141 New Elf

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  15. dmoore

    dmoore Senior Elf

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