Adafruit_Neopixel Library Fill() Function

Projects Programming
1

I'm trying to use the Adafruit_Neopixel fill() function to light two separate segments of the Neopixel strip. It looks like I'm doing something wrong with the color input. The first line should fill the pixels from 1 -10 with Red. The second line should fill the pixels from 20 to the end (129) with blue.

The second fill command is working but not the first. Can someone tell me the correct syntax?

#include <Adafruit_NeoPixel.h>

#define LED_COUNT 129
#define LED_PIN A4

Adafruit_NeoPixel strip(LED_COUNT, LED_PIN, NEO_GRB + NEO_KHZ800);
void setup() {
  strip.begin();
}

void loop() {
  strip.fill((255, 0, 0), 1, 10);
  strip.fill((0, 0, 255), 20);
  strip.show();   // Send the updated pixel colors to the hardware.
}

I see the documentation for the fill() function at https://learn.adafruit.com/adafruit-neo ... ibrary-use. It's not clear on how to input the color. I think because the syntax of the color input on the first is wrong, its interpreting it as no color or blank.

2

Further down the page is this example to get a colour value:

uint32_t magenta = strip.Color(255, 0, 255);

Try that and use it in the fill.

3

Thank you!!!! Couldn't figure that out.

4

You can't build complex arguments to subroutines like that in C/C++
It doesn't result in an error, because (255, 0, 0) is a valid C statement invoking the "comma" operator (which is ... obscure and to be avoided) that evaluates to 0.