WS2812 compatible (NeoPixel) Libraries

[J.B. Kuma]

I've tested a number of libraries so far and AdaFruit's seems to be the most ready to go. Others may work with a some effort, but not out of the chute. If you have had better luck let me know.

The good news is that even though the demo includes a bunch of delays and such, the SAMD21 board I'm using was able to continue reading the SD and looping without issue.

[J.B. Kuma]

FastLED works, but may require a small tweak to the library depending on what board you are using and which board manager.

For MKRzero
FastLED\platforms\arm\d21\fastpin_arm_d21.h file and add this code as one of the platform pin mapping cases:
#elif defined(ARDUINO_SAMD_MKRZERO)
#define MAX_PIN 22
_DEFPIN_ARM( 0, 0, 22); _DEFPIN_ARM( 1, 0, 23); _DEFPIN_ARM( 2, 0, 10); _DEFPIN_ARM( 3, 0, 11);
_DEFPIN_ARM( 4, 1, 10); _DEFPIN_ARM( 5, 1, 11); _DEFPIN_ARM( 6, 0, 20); _DEFPIN_ARM( 7, 0, 21);
_DEFPIN_ARM( 8, 0, 16); _DEFPIN_ARM( 9, 0, 17); _DEFPIN_ARM( 10, 0, 19); _DEFPIN_ARM( 11, 0, 8);
_DEFPIN_ARM( 12, 0, 9); _DEFPIN_ARM( 13, 1, 23); _DEFPIN_ARM( 14, 1, 22); _DEFPIN_ARM( 15, 0, 2);
_DEFPIN_ARM( 16, 1, 2); _DEFPIN_ARM( 17, 1, 3); _DEFPIN_ARM( 18, 0, 4); _DEFPIN_ARM( 19, 0, 5);
_DEFPIN_ARM( 20, 0, 6); _DEFPIN_ARM( 21, 0, 7);
#define SPI_DATA 8
#define SPI_CLOCK 9
#define HAS_HARDWARE_PIN_SUPPORT 1

or

change the following line:
#elif defined(ARDUINO_SAMD_MKR1000) || defined(ARDUINO_SAMD_MKRZERO)

source: github.com/FastLED/FastLED/issues/414