Merge pull request #3709 from jamesmunns/james/ws2812b-note

Add note for nRF52840-dk board details
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Dario Nieuwenhuis 2025-01-02 18:27:24 +01:00 committed by GitHub
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@ -14,6 +14,16 @@ use {defmt_rtt as _, panic_probe as _};
// https://cdn-shop.adafruit.com/datasheets/WS2812B.pdf.
// This demo lights up a single LED in blue. It then proceeds
// to pulsate the LED rapidly.
//
// /!\ NOTE FOR nRF52840-DK users /!\
//
// If you're using the nRF52840-DK, the default "Vdd" power source
// will set the GPIO I/O voltage to 3.0v, using the onboard regulator.
// This can sometimes not be enough to drive the WS2812B signal if you
// are not using an external level shifter. If you set the board to "USB"
// power instead (and provide power via the "nRF USB" connector), the board
// will instead power the I/Os at 3.3v, which is often enough (but still
// out of official spec) for the WS2812Bs to work properly.
// In the following declarations, setting the high bit tells the PWM
// to reverse polarity, which is what the WS2812B expects.