addressable.wiki

APA102

SPI RGB · APA Electronic · apa102

Channels
RGB
Bits / channel
8
Supply
4.5–5.5 V
PWM
20 kHz
Backup data
no
Packages
1

The main SPI-driven alternative to the WS2812 family. Two wires instead of one, in exchange for timing that does not matter, very high PWM frequency, and a per-LED 5-bit global brightness field. The right choice when the processor is busy or a camera is pointed at it.

Refresh & flicker

~20 kHz PWM, high enough to be invisible to cameras, which is why these are the default choice for persistence-of-vision and film work. Note that reducing global brightness superimposes a much lower-frequency PWM, which can reintroduce visible flicker.

Timing

SourceT0HT0LT1HT1LPeriodRateReset±
datasheet — — — — — — — —
Because the clock is explicit, timing is not critical and interrupts cannot corrupt a frame - the single biggest practical advantage over the WS2812 family.

Clones & compatibility

“Compatible” is never stated bare here — each relationship carries how strong the claim is, and what bites if you assume too much.

  • near clone SK9822

    Frequently sold as interchangeable and usually works, but the SK9822 implements global brightness as a real current source rather than superimposed PWM, runs a lower PWM frequency, updates non-staggered, and differs in end-frame handling. Not reliably drop-in. source ↗

  • drop in of this APA102C

    A cost-reduced APA102 sold under a near-identical name. Driven identically; the difference is manufacturing, not protocol.

  • drop in of this APA107

    Driven identically to the APA102 by every library. Marketed as a higher-refresh successor.

  • near clone of this HD107S

    Driven with the APA102 protocol by every library, and generally treated as a faster APA102. The caveat is that the specifications are vendor claims rather than a verifiable manufacturer datasheet, and the HD107S, APA107 and APA102 are frequently conflated in listings.

  • protocol compatible of this HD108

    Same SPI framing concept, but each pixel carries 16 bits per channel, so an APA102 driver will not produce correct output without explicit HD108 support.

  • near clone of this SK9822

    Widely sold as an APA102 equivalent and usually works, but it is not a drop-in. Global brightness is a controlled current source rather than superimposed PWM, so it does not flicker when dimmed. PWM is 4.7 kHz against 20 kHz. The update is non-staggered, and end-frame handling differs - a driver that relies on the APA102's end-frame behaviour can misbehave.

Library support

FastLED
APA102 ↗
Adafruit_DotStar
DOTSTAR_BGR
WLED
APA102

Sold by Adafruit as “DotStar”.

Parts using this protocol

Dating evidence

Evidence, not a release date. A library commit proves the part existed by that date and says nothing about how long before.

  • 2014-08-27 first documented cpldcpu, 'APA102 aka Superled' - the first detailed public analysis of the part ↗ day
  • 2014-11-30 first documented cpldcpu, 'Understanding the APA102 Superled' - full protocol and PWM teardown ↗ day
  • 2013-05-30 first library support FastLED — first commit introducing APA102 ↗ day
  • 2019-05-01 first library support WLED — first commit introducing APA102 ↗ day