I recently got some of those CJMCU-8*8
labeled LED RGB Matrix boards.
According to what is printed on the boards, they are opposed to be built
up on WS2812B
RGB "Neopixel" LEDs. Connecting the matrix to an Arduino however,
I had no luck at all on my first attempt. Later I found that these PCBs were
totally misleadingly labeled:
DIN
andDOUT
labels are exchanged (!)- the board uses
WS2812
LEDs, which use the WS2811 driver IC (but is labeled asWS2812B
)
Front | Back |
---|---|
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Knowing that, I could get the board up and running using the FastLED library without problem. See the Demo sketch for an example. The sketch assumes the CJMCU board is connected to pin D9 of an Arduino.
Since the WS2812 (which is an WS2811 driver IC packaged with a LED) and the WS2812B use the same protocol, the difference in type make no difference in interfacing the LEDs with e.g. the FastLED library.
The WS2812 uses a 6 pin package. So if your LEDs have 6 pins instead of 4, then chances are your PCB is populated with WS2812 LEDs.