Interfacing WS2812B addressable LED to Wemos D1 mini
It is standard for CMOS that anything above 0.7VCC is considered a logical high and anything below 0.3VCC is a logical low. So if your WS2818B runs at 5V you will need a signal of at least 0.7 * 5 = 3.5v to be able to address it with a consistent logical high. Now in practice things might just work (even if your logical high is 3.3v) but I wouldn't call it &quot;safe for production&quot;. The Wemos has a logical high of 3.3v regardless of how it is powered, so you will need to either step up the logical level of the Wemos through some external circuitry or (which is easier) diminish the supply voltage of the RGB strip to a VCC such that 0.7VCC &lt; 3.3v. A simple compromise is to run both at 3.5v which is cutting close to the max rating of the Wemos and the min rating of the strip. Alternatively (as dandavis suggests) power both at 5v but put a diode in between the supply voltage and the WS2812B. This will drop the supply voltage of the WS2812B to 4.4v for a regular diode and now a logical level of 3.3v is enough since 0.7*4.4 = 3.08 &lt; 3.3v.