int32_t i = (x * NEOPIXEL_HEIGHT) + y; // vertical strip start from left top // int32_t i = (x * NEOPIXEL_HEIGHT) + ((x % 2) ? y : (NEOPIXEL_HEIGHT - y - 1 ...
On (at least) an arduino nano, i.e. atmega328p ... Using any version of the FastLED library, every minicore version >= 3.1.x fails to illuminate leds using the FastLED library. It compiles ok, just ...