I know they make Neopixel led 'rings'.. using WS2812B or SK6812 - based LEDs.
But do they make DotStar based led rings? (APA102C or ADA102 - based LEDs)?
Update: I see there is an APA104 led too? (differs from the APA102 because the 104's are also a 1 wire set-up? Like the Neopixels? So do the 104's have the same timing requirement as the WS28xx's? or does it take advantage of NOT needed that like the APA102's?)
My current project uses a serial based .wav/.mp3 player... and with the timing requirements of the Neopixels and the fact it disables interrupts (with mess with the serial comm.) during updating animations/patterns..etc..
So I am looking into using DotStars instead. (however I havent been able to find any?)
As an alternate solution.. I was thinking of perhaps trying to source some blank Neopixel ring PCB's... however, I dont think they will work now, seeing as the DotStar have a 6-pin pinout.. and the Neopixels only have a 4-pin pinout.
So I guess I am looking for an alternate solution or sourcing some DotStar rings?
I need to research the differences between:
WS2812(b)
WS2813
SK6812
*Neopixel leds
and
APA102
APA104
*DotStar leds.. (if the APA104's even qualify for this DotStar category...I'm leaning towards 'not' though)
Interested to hear some suggestions/thoughts.
Heck.. I dont really care about the number.. I just need an RGB, individually addressable led (ring) that doesnt have the same time requirements (disables interrupts) as the Neopixel lines of LEDs do.
I haven't seen any either. The selection of APA102-based boards available is pretty poor (hell, even strips are hard to find with the APA102TW ones, which are significantly better than the APA102C's that you see around). I think you'd need to design a board and have it fabbed for that. Or hire someone (like me) to do so.
DotStar is what Adafruit calls it's APA102 offerings.
Neopixel is what Adafruit calls it's WS2812(B) offerings.
WS2812B is improved WS2812 (original had 6 pins with two supply lines or something, B simplified that with 4)
WS2813 is improved WS2812B that again has 6 pins - with two data lines, which are connected together at one end; the second line is a "backup" so that if one of the leds is damaged, it will go to the backup data line, and the LEDs after will still work (presumably demanded by people who use them in signs and stuff - so the sign outside the cafe won't go from reading "Try our assam tea" to "Try our ass").
SK6812 is a clone of WS2812B; generally interchangible, though you can get timing that works with 6812's but not 2812's - SK6812's are available in color options other than RGB, eg, RGBW, WWA)
APA104 - looks like a a WS2812 clone?
APA102 - data and clock, so not timing critical (can also be updated much faster, if your controller can blast out data that fast). Comes in two versions, the C and TW version - C looks like 2812's and is made in china, TW has a square transparent window, heatsink pad on bottom, and a brighter red LED, and is made in taiwan.
Can I think of SK9822 as clones of the APA102C then?
(If the SK6812 are clones of the WS2812's?)
I have seen the APA102TW's.. and thought the trans window looked odd! LOL (but I didnt know those were TW's until you just enlightened me!) haha..
I think you might be right.. I may need to just 'roll my own' here..
I suppose I can just open up Eagle and whip something up.. (or just take the open source Neopixel ring schematic/brd files and alter those as a base to start from.)
should probably add the cap on board as well... (do these need a resistor on the data lines like the DIN does for the Neopixels do you know?)
Thinking about this.. I shoudl probably just order regular DotStar leds/strip to ensure it works (better).. then what I am dealing with currently.. before I go through all this trouble.. LOL
Thanks for the feedback (and background), it was truly helpful!
You can try the experimental NeoPixel drivers for SAMD21. Using DMA to drive the LEDs means interrpts do not have to be disabled. But you must switch to a SAMD Arduino and adjust for 3.3V logic levels.
SK9822 is a APA102 clone - though there are some subtle differences. It looks like they used the datasheet as a reference, rather than the actual APA102 behavior. They also don't appear to use PWM, but rather a controlled constant current source for the global dimming! IIRC there are similar differences between SK6812 and WS2812B.
I was sent an spreadsheet... but dont have it with me at work..
diameter 100mm 36leds/ring sk9822 rgb led ring now Exw price is $5.80USD per pcs
diameter 80mm 28leds/ring sk9822 rgb led ring now Exw price is $4.82USD per pcs
Is what they have/offer.. roughly $5 & $6 USD respectively..
Their dotstar STRIPS.. are only available in 10M (2-reel) batches.. at $161.00 or something..
Nice... I never found these while searching! Thanks Mike.
To update:
Store front:
Not extremely cheap:
$21.27 US Dollar for the circle
But it is definitely an alternate solution.
The link/factory listed above is much cheaper, however after some chit-chat... they claim they can only send via DHL or FEDEX.. and it costs $29.00 or so!!!!.. so while much cheaper.. the shipping KILLS IT FOR ME! (unless there is a huge bulk order or something.. that makes the shipping costs minimal)
I suppose I'll just end up designing my own one of these weekends..
I can assemble/re-flow in my basement to complete them. (I'm surprised there are no open source schematic/board files already out there!)
I guess finding a Neopixel variant would speed up the process as you only need to edit a few things.. and add some traces.
Yes it works both ways. I won a $30.00 voucher from AdaFruit in a photo competition. It cost be about a further $40.00 to buy a $30.00 bluetooth board in courier charges and taxes. They even charged me $10 for collecting the tax from me.
