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Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
@Kolban
I spent the bulk of the day trouble shooting my issue and think I found it ... here is the story and the then the conclusion. With so many variables in my story, I wasn't sure where to start. Was it timing with Espruino, interrupts in ESP8266, bad pixel strips, bad power, bad comprehension on my part .... so many possibilities.
What I did was broke out an Arduino and used it to drive my NeoPixel strip through an Arduino sketch which was an implementation of my JavaScript sketch but this time in C. It worked fine and all the pixels lit properly. I watched it for a long period of time. My confidence in the NeoPixel strip was now high. I captured a low level timing through a logic analyzer and saved the results. Then I went back to the ESP8266 and Espruino using the same strip. Again, same issues as before. I captured the input timings into the NeoPixels and generated by Espruino/ESP8266 and compared them against my "reference set" which I took from the Arduino. Although not identical, they were within tolerance of what I have been reading from NeoPixel theory.
Next I had an idea ... the output of one NeoPixel feeds into the input of the next. Now I decided to capture signals from the input to the first NeoPixel to the output of the next ... and ... Aha!! We got something. When the pixels started not showing correctly, I saw that the input to the first NeoPixel looked "good" but the output from the first NeoPixel was poor ... i.e. a lot of missing high signals on the DOUT line. What this was telling me was that the first NeoPixel was not forwarding its correct sequence of pulses.
Now we get to cut to the chase ... I knew that powering a NeoPixel strand from the 5V output of ESP8266 wasn't going to fly so I was using an MB-102 as a power source for the NeoPixel strand. I was delivering 5V from the MB-102s to the NeoPixels with a common ground to the ESP8266 (NodeMCU dev kit). This had been my test environment. Knowing that the Arduino was a working test environment, I took the MB-102 out of the story and powered my NeoPixels from the 5V/GND of the Arduino ... i.e. I am using the Arduino ONLY as a source of power to the NeoPixels. I obviously continue to have a common ground ....
and the result ... perfection. I have been running the strand for about 10 minutes now with it right in front of me and not a single glitch. What this is telling me is that power output of the MB-102 is not sufficient/clean enough to power the NeoPixel strand. I don't have nearly enough skills in electrical or electronics to know why ... tomorrow I'm going to start studying up on MB-102s ... and also see what I have in my box of bits for a power source that is neither MB-102 nor an Arduino ... but what I have now is an ESP8266 running Espruino driving a NeoPixel strand in exactly the fashion I had hoped for and that others had said they had achieved. I'd be really interested to hear from you what you are using to power your NeoPixels/ws2812s?