Using millis() to turn on ws2812 led for 3 seconds

[bokthestudent]

Hi im a newbie trying arduino coding, I wanted the ws2812 to be controlled by button, so if the button is pressed the ws2812 will turn on once for 3 seconds then turn off.
Thanks for your suggestions

[majhi]

bokthestudent:
Hi im a newbie trying arduino coding, I wanted the ws2812 to be controlled by button, so if the button is pressed the ws2812 will turn on once for 3 seconds then turn off.
Thanks for your suggestions

First things first, post your code so people can take a look at it and see what you're doing or not doing.

[bokthestudent]

currTime = millis();

  if (buttonState ==  HIGH ){
        ledState = ON;
        remTime=currentTime;
      }

  if (currTime - remTime >= 3000 && ledState == ON ) {
        #define BRIGHTNESS  180
         FastLED.setBrightness(BRIGHTNESS);
         fill_solid(leds[0], NUM_LEDS_PER_STRIP, CRGB::Red);
         FastLED.show();
   }

[ToddL1962]

Although it seems like a simple problem, what if the button is pressed while the LED is On? Do you want to ignore it, turn the LED off, or restart the 3 second timer? The answer to the latter question will greatly affect how this is coded.

In the meant time, here are a couple of tutorials to look at. I would start with just getting the LED to turn on for 3 seconds then add the button:

BlinkWithoutDelay

StateChangeDetection

[ToddL1962]

bokthestudent:

currTime = millis();

if (buttonState ==  HIGH ){
        ledState = ON;
        remTime=currentTime;
      }

if (currTime - remTime >= 3000 && ledState == ON ) {
     
        ledState =  ON;
        #define BRIGHTNESS  180
        FastLED.setBrightness(BRIGHTNESS);
        fill_solid(leds[0], NUM_LEDS_PER_STRIP, CRGB::Red);
        FastLED.show();
  }

That is not a complete sketch.

[majhi]

bokthestudent:
currTime = millis();

if (buttonState == HIGH ){
ledState = ON;
remTime=currentTime;
}

if (currTime - remTime >= 3000 && ledState == ON ) {
remTime = currTime;
ledState = ON;
#define BRIGHTNESS 180
FastLED.setBrightness(BRIGHTNESS);
fill_solid(leds[0], NUM_LEDS_PER_STRIP, CRGB::Red);
FastLED.show();
}

Which is only a snippet of your code. You'll need to post your ENTIRE sketch.