Faulty NeoPixel RGB LED? Green channel erratic behavior

The behavior of the RGB LED in the CubeCell V2.2 seems to be faulty. I observed that calling the show() function turns the green part of the LED on, although the value of the getPixelColor(0) doesn’t reflect it.

To show this, I modified the RGB example:

#include “CubeCell_NeoPixel.h”

CubeCell_NeoPixel pixels(1, RGB, NEO_GRB + NEO_KHZ800);

void setup() {

  // put your setup code here, to run once:

  pinMode(Vext,OUTPUT);

  digitalWrite(Vext,LOW); //SET POWER

  pixels.begin(); // INITIALIZE NeoPixel strip object (REQUIRED)

  pixels.clear(); // Set all pixel colors to 'off'

}

uint8_t i=0;

void loop() {

  // put your main code here, to run repeatedly:

    pixels.setPixelColor(0, pixels.Color(1, 0, 0));

    pixels.show();   // Send the updated pixel colors to the hardware.

    delay(100); // Pause before next pass through loop

    pixels.setPixelColor(0, pixels.Color(0, 1, 0));

    pixels.show();   // Send the updated pixel colors to the hardware.

    delay(100); // Pause before next pass through loop

    pixels.setPixelColor(0, pixels.Color(0, 0, 1));

    pixels.show();   // Send the updated pixel colors to the hardware.

    delay(100); // Pause before next pass through loop

    i+=10;

}

This should cycle the channels at a low brightness. However, green flashes can be observed:

https://www.youtube.com/watch?v=1UpJDWJ2uMM

I tested this in two different devices (same revision), and seems consistent. It also happens when I set the color to 0.

This is a bummer, since I need the RGB for my specific application, and this board seemed to be very promising.

Edit:
Found http://community.heltec.cn/t/htcc-ab01-v2-color-problem/13476/7 , which seems to indicate it’s a widespread problem.

When I had the same problem, Heltec suggested me the following:

This issue has been fixed in Github. You can try installing the development environment through Git. For environmental updates, Heltec prioritize pushing updates to Github, and usually update the environment in the library manager when there are important updates. Heltec recommend using Git.
https://docs.heltec.org/en/node/asr650x/htcc_am02/quick_start.html#via-git

Was you able to fix the problem? I am using the latest github version but the problem with the erratic green RGB Led is still present thats very annoying.

I got 2 brand new HTCC-AB01 V2.2 boards. It has the same RGB LED problem as you described. I did some test and determined that the root cause seems to be the Green LED turn on randomly during the show( ) or clear( ) function call. The Red and Blude LED work fine. But when Green LED turns on randomly during these calls, it affect the RED or Blue color or cannot turn off RGB LED (i.e. the Green LED turn on when calling clear( ) or setpixels to (0, 0, 0) )
Hope Heltec can fix this problem soon.

I have 20 version 2.2 boards. On 10 boards the Neopixel LED looks a little different than on the other boards. On these boards there is a problem with the green LED. I think the problem is related to the fact that there are different batches of version 2.2. Is there a solution for this?

This bug was fixed with version 1.6.
Alternative you can copy the file asr_NeoPixel.c to the Version 1.5

Thank you very mutch!