WS2812B issues

Sat 2018.08.11
Hello @AdaMan82,

From #6 above

re: 'I've used the resistor wrong' 'Does that make sense?'

If your wiring matches your diagram, you have connected as @Gordon indicated in #5

Are you programming the Pico using power from a USB cable, then removing that cable then connecting the auxiliary battery supply?

per #2

I disagree with the output that @allObjects indicates, but agree with the tactic. Try:

require("neopixel").write(B15, [0,0,0]);

which should be no color or off instead of

require("neopixel").write(B15, [255,0,0]); // turn first LED Red

which should be Red on

ref below 'Software' heading: http://www.espruino.com/WS2811

Then maybe try a different pin as allObjects suggested, both in software and hardware pin and pullup change

ref image: http://www.espruino.com/Pico
SPI2 B15
SPI1 A7
SPI3 B3

Note to check with Gordon to see if just changing the pin designation
for MOSI SPIn is sufficient with new 'neopixel' module as the work I
did two years ago used old documentation e.g. SPI2.setup({baud:3200000, mosi:B15});

But, I'm puzzled.

re #1: 'but they should power one LED'

re #6: 'The whole thing still lights up'
re #4: 'all LEDs light up'
re #1: 'but I can't get it to do anything other light up completely.'

Are you using just one Neopixel segment physically separated from the rest, rather than the entire strip as the image provided suggests? and, . . . . How many Neopixels are in the strip?

I'm sure you were aware that with the strip, the data line is daisy-chained between each individual Neopixel and that a data stream need be sent to that strip.

Have you tried 3 x RGB triplets:

require("neopixel").write(B15, [255,0,0, 0,255,0, 0,0,255]); // turn first 3 LEDs, Red, Green, and Blue

ref below 'Software' heading: http://www.espruino.com/WS2811

Other things to try:

1. Which tutorial are you using? Please include link and heading
   reference so that we may follow your thoughts
   
2. Include the entire code block you are sending the Pico as a code section (see 'Formatting Help' in link below reply dialog next to
   cancel or 'code' button next to 'preview' before submitting)
   
3. Provide a snap shot of the hardware so others may triple check the wiring