Led ws2812 with switch

[philipp1987]

Hi, everyone.
I'm still in the early stages of learning to program. However, I am slowly despairing of myself and am asking you for advice.

how do I make the led not react to the specified value but slowly (500ms) dim up? i have an rgb ws2812 adafruit on the arduino uno r3...

this is the current programming

int switchState = 0;                                                                            //zwischenspeicher schalter
#include <Adafruit_NeoPixel.h>
#define PIN 6                                                                               // led daten anschluss        
#define NUMPIXELS 12                                                                           // anzahl led pixels          
Adafruit_NeoPixel pixels = Adafruit_NeoPixel (NUMPIXELS , PIN , NEO_GRB + NEO_KHZ800);       

 
void setup() {
  pinMode (2,INPUT);                                                                          // schalter eingang
  pixels.begin();                                                                             //initialisierung led
  pixels.show();                                                                              //ausschalten aller leds
  
  
}

void loop() {                                                                                 // 0-255         rot,,grün,,blau
switchState = digitalRead (2);
if (switchState == LOW){                                                                      // der schalter ist aus
  pixels.setPixelColor(1,pixels.Color(0,0,0));
  pixels.show();
}

else{
  pixels.setPixelColor(1,pixels.Color(0,0,255));
  pixels.show();
  delay(4000);
}}

[DVDdoug]

I've never used NeoPixels or the library, but...

You have to "step it up". Each color has a brightness level between zero and 256 so you can count-up from zero a little slower than 2ms per step (although you may not want it to be linear (1)).
The Fade Example may help to explain but it won't work as-is with NeoPixels.

With only 12 NeoPixels you may be OK using delay() or delayMicros() but it takes time to write the NeoPixels so a millis() timer (like the Blink Without Delay Example) may work better than a regular delay().

(1) A linear fade doesn't look linear because 10-count from 10-to-20 is a bigger percentage change than 245-to-255. In fact you probably won't notice the difference between 245 & 255. But with a fast 500ms fade that shouldn't be an issue.

[kolaha]

#include <Adafruit_NeoPixel.h>
#define PIN 6                                                                               // led daten anschluss        
#define NUMPIXELS 12                                                                           // anzahl led pixels          
Adafruit_NeoPixel pixels = Adafruit_NeoPixel (NUMPIXELS , PIN , NEO_GRB + NEO_KHZ800);


void setup() {
  pinMode (2, INPUT_PULLUP);                                                                         // schalter eingang
  pixels.begin();                                                                             //initialisierung led
  pixels.show();                                                                              //ausschalten aller leds
}

void loop() {                                                                                 // 0-255         rot,,grün,,blau
  if (digitalRead (2) == LOW) {                                                                     // der schalter ist aus
    for (byte i = 250; i > 0; i -= 5) {
      pixels.setPixelColor(1, pixels.Color(0, 0, i));
      pixels.show();
      delay(2);
    }
  }

  else {
    pixels.setPixelColor(1, pixels.Color(0, 0, 255));
    pixels.show();
    delay(4000);
  }
}

[philipp1987]

Hello kolaha
thanks for the reply... with the attached program, the led flickers until i press the switch. what am I doing wrong?

[kolaha]

describe what behavior of system do you expecting.
example:

LED are off 
I press and release the button 
LED are slowly lights up to maximum in time of 500ms
I press and release the button 
LED goes off immediately 
go to start

[sterretje]

How is your button wired? Between V_cc and pin 2 or between GND and pin 2?

[philipp1987]

[philipp1987]

the switch is pressed, the led dims up (500ms) and goes out after 4000ms

then start again...

at the moment it always flickers until it is pressed. switches on without dimming and goes off after (4000).

[kolaha]

#include <Adafruit_NeoPixel.h>
#define PIN 6                                                                               // led daten anschluss        
#define NUMPIXELS 12                                                                           // anzahl led pixels          
Adafruit_NeoPixel pixels(NUMPIXELS , PIN , NEO_GRB + NEO_KHZ800);

void setup() {
  pinMode (2, INPUT_PULLUP);                                                                         // schalter eingang
  pixels.begin();                                                                             //initialisierung led
  pixels.show();                                                                              //ausschalten aller leds
}

void loop() {                                                                                 // 0-255         rot,,grün,,blau
  if (digitalRead (2) == HIGH) {                                                                     // der schalter ist aus
    for (byte i = 0; i <250; i += 5) {
      pixels.setPixelColor(1, pixels.Color(0, 0, i));
      pixels.show();
      delay(2);
    }
    delay(4000);
    pixels.clear();
    pixels.show();
  }
}

[philipp1987]

Thank you very much...
It goes perfekt.