how can I turn on LEDs,

Sheena_Variasi · January 28, 2019, 9:41pm

how can I turn on LEDs, if i want to turn on led 1 and 5 simultaneously?
some have the code?

marmil · January 29, 2019, 4:50am

This would make them different colors, but light up at the same time.
leds[1] = CRGB(0,255,0);
leds[5] = CHSV(0,255,255);
FastLED.show();

Or this would also work and would make them both the same color.
leds[1] = leds[5] = CRGB(0,0,255);
FastLED.show();

The display of the pixels does not change until you call FastLED.show(). Make all your updates, and then call show to display all those updates at the same time.

Sheena_Variasi · January 29, 2019, 6:03am

work sir, thank you.

the last question,
is there another way to blink the led besides this code?

leds[0] = CRGB(0,255,0);
leds[1] = CRGB(0,255,0);
leds[2] = CRGB(0,255,0);
leds[3] = CRGB(0,255,0);
leds[4] = CRGB(0,255,0);
leds[5] = CRGB(0,255,0);
FastLED.show();
FastLED.clear();
delay(50);
FastLED.show();
delay(50);

marmil · January 29, 2019, 6:11am

Since you have a continuous range there [0-5], you can work that into a for loop. Have a look at the FastLED Cylon example for some ideas.

github.com

FastLED/FastLED/blob/master/examples/Cylon/Cylon.ino

#include <FastLED.h>

// How many leds in your strip?
#define NUM_LEDS 64 

// For led chips like Neopixels, which have a data line, ground, and power, you just
// need to define DATA_PIN.  For led chipsets that are SPI based (four wires - data, clock,
// ground, and power), like the LPD8806, define both DATA_PIN and CLOCK_PIN
#define DATA_PIN 2
#define CLOCK_PIN 13

// Define the array of leds
CRGB leds[NUM_LEDS];

void setup() { 
	Serial.begin(57600);
	Serial.println("resetting");
	LEDS.addLeds<WS2812,DATA_PIN,RGB>(leds,NUM_LEDS);
	LEDS.setBrightness(84);
}

This file has been truncated. show original

Sheena_Variasi · January 29, 2019, 6:19am

i want the leds turn on same time but the leds has flashing effect like police light strobe.

Michel_G_Khoury · January 29, 2019, 7:04am

What Marc meant is that you can use same code for loop than on the Cylon example. In particular this part :
for(int i = 4; i >= 0; i–) {
leds[i] = CHSV(0, 255, 255);
}
FastLED.show();

4 because you want 5 LEDs. And show() out of the loop because you want them all at the same time.

Andrew_Tuline · January 29, 2019, 3:47pm

Here’s a way to blink all 5 LED’s at once without any ‘delay’, ‘for’ or ‘if’ statements:

void loop () {
uint8_t j = (millis()/500) % 2; // bool works as well.
fill_solid(leds, 5, CHSV(0, 255, j*255));
FastLED.show();
} // loop()

Your loop will run at FULL speed.

Oh, and if you want to alternate between red and blue:

fill_solid(leds, 5, CHSV(j*160, 255, 255));

Sheena_Variasi · January 29, 2019, 9:59pm

@Andrew_Tuline thanks sir, i will try this.