Hi - I’m a fairly experienced hobbyist and programmer, playing with Neopixels for the first time. I have a very basic setup – an own-design board with 20x SMD WS2812Bs in a single string, driven by a vanilla Uno (which otherwise works fine).
Electrically, I’ve checked that all the LEDs have power at the right pins, that there is continuity between the Arduino data pin and the first DIN, and also from each DOUT to the next DIN. I have a 470uF cap across the 5V supply. Running off USB power: Mac → Uno → LEDs.
Product ID: 0x0043
Vendor ID: 0x2341
Serial Number: 756383030373514112F0
Speed: Up to 12 Mb/sec
Manufacturer: Arduino (http://www.arduino.cc)
Location ID: 0x14200000 / 30
Current Available (mA): 500
Current Required (mA): 100
Extra Operating Current (mA): 0
But, I get nothing, rien, nichts, لا شيئ
The code is about as pared back as I can make it, borrowed from one of the examples. (NEOPIXEL and WS2812B are synonyms, right ?).