Hi, can anyone point me in the right direction.

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1

Hi, can anyone point me in the right direction. I am trying to turn on and off a WS2812b LED from a button.
My code compiles OK, but when i upload it the LED is red and when i push the button it goes green.
I would like the LED to be off and when i push the button it goes Red and stays red when i release the button.

Here is the code

#include <FastLED.h>
#define NUM_LEDS 1
#define DATA_PIN 7
const int keyPin = 12; //the number of the key pin
const int ledPin = 7;//the number of the led pin
CRGB leds[NUM_LEDS];
void setup()
{
pinMode(keyPin,INPUT);//initialize the key pin as input
pinMode(ledPin,OUTPUT);//initialize the led pin as output
delay(2000);
// FastLED.addLeds<WS2811, DATA_PIN, RGB>(leds, NUM_LEDS);
FastLED.addLeds<WS2812B, DATA_PIN, GRB>(leds, NUM_LEDS);
}
void loop()
{
if(digitalRead(keyPin) ==HIGH )
{
digitalWrite(ledPin,HIGH);//turn on the led
}
else
{
digitalWrite(ledPin,LOW);//turn off the led
}
//fill_solid(leds, NUM_LEDS, CRGB::Red);
for (int i = 0; i < NUM_LEDS; i++) {
leds[i] = CRGB::Red;

FastLED.show();
delay(30);
}
}

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2

Hi, welcome to working with “smart” pixels.

the led is a “smart” led, and it expects to receive instructions from the FastLED library, not just an on or off (high or low).

when you press the button, your code does this:

digitalWrite(ledPin,HIGH);//turn on the led

You want your code to send a change colour instruction.

Check the blink demo included with the library.

Come back if you’re still stuck after that.

3

Thanks. I’ll work with this this week. I’ll let you know how i get on.

4

Ross, you might need to store the on/off state also. Have a look at this example to combine with the example Stuart mentioned.
[Edit: corrected link]
http://arduino.cc/en/Tutorial/ButtonStateChange

The button might work fine, or you might find that the it works erratically/inconsistently, in which case you might need to also look into debouncing.

5

@Ross_Malyon if you want, you can use my button code as well:

Here you can see how to use it:

I think it is really helpful, because if you hold down the pushbutton inside a loop - and you want to “toggle” it can flash on and off really fast.

6

@Jurgen_Skrotzky Thanks, but i really struggling to get my head around your button code. I wish they had some workshops here to help me develop a deeper understanding of code.

7

@Stuart_Taylor
Nearly there! Using Matthias Hertel’s One Button Master. I am going to try his two button master beacuse i want to try and call say eight different ‘cues’. Thanks :slight_smile:

8

Great news! Dont forget to #showoffyourwork when its done.

9

I will, Don’t worry. Planning some beach parties and will be using various LED objects.