New WS2812B RGB LED

New WS2812B RGB LED

The WS2812B RGB LED has been revised with new silicon (date codes from 2017), and an unannounced change that is breaking current code has happened: the reset time has gone from 50 microseconds to 300 microseconds according to the datasheet.  There is a visible difference between the parts:

The difference between the old and the new controller IC is apparent: the old one is rectangular whereas the new variant is square.

Here is a page from the updated datasheet:

So in order to get these to work the new minimum reset time is 300 microseconds, check your code!