Hi all. I thought that I’d post in ‘quasi-related’, as it’s not strictly about FastLED, yet… I’ve been running my Xmas lights off an Arduino for 2 years now using a different driver library and SPI for %v WS2801 and LPD8806, so I’m not a total newbie. However, I just purchased some all green wire WS2811 lights 12v:
I got these because the all green 100 node meant that my wife will allow them on the tree (unlike the multi coloured monstrosities of previous years!)
I’ve got a 12v to 5v convertor so I can run the Arduino Due off the same power supply. I also had to quickly learn about logic levels which I’ve been ignorant about before - so I’ve ordered a bi directional logic level converter.
Now, my problem is that the wires are all green, so I don’t know what they are!!! I contacted the supplier, who helpfully sent the following diagram.
I dutifully wired up the powers supply connector (on the right) as per the diagram, and plugged it in. Nothing happened (I’ve not got the logic level convertor yet, but I thought it was worth a shot as last year’s pixels had 5v logic running of an Arduino Due 3.3v okay)
I then noticed that the left hand connector on the image (after much mental gymnastics of orientating in my head!) has the ground/12v on opposite sides!!! (look for the groove and it’s compliment)
Does anyone have these (or a coloured version) and can help with a definitive wiring? - I don’t trust the supplier about wiring now.
Thanks! (Hopefully I’ll be able to try FastLED when this is sorted)
With these kinds of things you’re best off testing with a multimeter/continuity tester (though thinking harder about it that might not be possible without opening up the last pixel and checking the markings on the board? You might want to consider that, as you’ll probably smoke the first pixel if you pump 12V into its data line.)
In any case, the Due has its own 12V->5V regulator so you don’t need an external one. Just plug the 12V from your power supply into the Due’s barrel jack and it will work fine.
On level converters, nothing aside from the 74HCT245 will work. If it’s the Sparkfun BOB-12009 you’re waiting on, round-file it as soon as it arrives and save yourself the trouble. If you’ve clean power and a short enough run between the Due and the first pixel you’ll almost certainly be fine hooking your data line straight to the output pin.
Thanks Robert. I should have done more research first - I was too excited by the green wire. I may order some more 5v WS2801 4 wire (green), as I’m not sure these will be fast enough without SPI anyway! I do some pretty funky stuff.
Unfortunately, there’s no such thing as “definitive wiring”. You can use a multimeter/continuity testing to find the power and ground lines. Data in and data out won’t be connected directly. The question is, do these provide protection against reversing power and ground?
Or to put another way, do you feel lucky?
In some ways, you are lucky - the due can currently do multi-way parallel output if you’re using the FastLED3.1 branch which would definitely give you improvement over the WS2801 speed, though not so much the LPD8806 (at least until I unleash my 24-30 way parallel output - but that would actually require a digix to get at all the pins).
The WS2811/WS2812 are inherently just pretty slow internally-- pretty much everyone doing POV gives up on them and moves to the much-faster LPD8806 or APA102.
You could, I suppose, break up one 32-pixel bar into eight four-pixel mini-bars, and go 8X faster – at the cost of a lot of extra wiring.
For POV we still basically recommend starting with fast LED drivers: APA102 or LPD8806.
Don’t POV with ws2812 - you can’t update them more than 400 times a second without them glitching.
Lpd8806 seems to happily take up to 2500 updates a second. Jury is still out on the apa102’s - but I believe it will be at least 500. However I’ve driven the apa102’s at over 5kHz and haven’t had them glitch out.
@Robert_Atkins When I started this post, you mentioned the 74HCT245
I’ve ordered one, but looking at the datasheet, I can’t figure out how to wire it up. Unlike the one I originally ordered, there is only one voltage input. My Sparkfun clone (which you rightly said wouldn’t work - has both a 5 and 3.3v input and it’s easy to figure out how to wire up.
Can you help, please? I only am using a single data channel, and no clock.
