I come here with what most probably is a very basic usage question.

Leo_Bettinelli · March 31, 2016, 5:58pm

I come here with what most probably is a very basic usage question. I am still dealing with the basics…

How do I handle the following code in order to have each of the 5 pixels cycling at a different speed?

#include “FastLED.h”
#define NUM_LEDS 5
CRGB leds[NUM_LEDS];

void setup() {
FastLED.addLeds<UCS2903, 49>(leds, NUM_LEDS);
}

void loop() {
static uint8_t hue = 0;
FastLED.showColor(CHSV(hue++, 255, 255));
delay(100);
}

Jarrod_Wagner · March 31, 2016, 7:56pm

Define an array with the determined speeds you’d like the LEDs to change to and an array to hold what they’re currently at.

Then make a loop that increments the current leds color and then sets that color using something like leds[i]=CHSV(currentcolor[i],255,255);

marmil · April 2, 2016, 4:46am

Leo, if it’s just 5 pixels (and if I understand what you’re wanting to do) I might try out using five hue variables (hue1, hue2, etc) and also five EVERY_N_MILLISECONDS setups, one for each pixel.
I’m curious what you come up with.

Leo_Bettinelli · April 2, 2016, 11:03am

so far I have this

#include “FastLED.h”
#define NUM_LEDS 5
CRGB leds[NUM_LEDS];

static uint8_t hue1 = 0;
static uint8_t hue2 = 72;
static uint8_t hue3 = 144;
static uint8_t hue4 = 216;
static uint8_t hue5 = 288;

void setup() {
FastLED.addLeds<UCS2903, 49>(leds, NUM_LEDS);
}

void loop() {
leds[0] = (CHSV(hue1++, 255, 255));
leds[1] = (CHSV(hue2++, 255, 255));
leds[2] = (CHSV(hue3++, 255, 255));
leds[3] = (CHSV(hue4++, 255, 255));
leds[4] = (CHSV(hue5++, 255, 255));
FastLED.show();
delay(100);
}

I am using “static uint8_t” because I saw it in use, not because I understand what it does

would you be so kind to guide me with “EVERY_N_MILLISECONDS”?

danke!

marmil · April 2, 2016, 2:50pm

I don’t think you need to use static uint8_t, just unit8_t.
Here’s an example of using EVERY_N_MILLISECONDS:

github.com

marmilicious/FastLED_examples/blob/master/beat8.ino

//***************************************************************
// beat8 example.  Moves pixel position based on beat8.
//
// -Marc Miller, Jan 2016
// Updated Feb 2016 - made move speed and fade rate variables.
//***************************************************************

#include "FastLED.h"
#define LED_TYPE LPD8806
#define DATA_PIN 11
#define CLOCK_PIN 13
#define NUM_LEDS 32
#define COLOR_ORDER GRB
#define BRIGHTNESS 50
CRGB leds[NUM_LEDS];

uint8_t gHue = 0;  // Used to cycle through rainbow.
uint8_t moveSpeed = 6;  // Higher value moves pixel faster.
uint8_t fadeRate = 80;  // Use lower value to give a fading tail.

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Here’s another that uses EVERY_N_SECONDS, which works the same except you give it a number of seconds instead of milliseconds:

github.com

marmilicious/FastLED_examples/blob/master/CRGBSet_example.ino

// Marc Miller, Jan 2016

#include "FastLED.h"
#define NUM_LEDS 32

//CRGB leds[NUM_LEDS];  // Not using this.  Using CRGBArray instead.
CRGBArray<NUM_LEDS> leds;

CRGBSet partA(leds(6,9));  // Define custom pixel range with a name.
CRGBSet partB(leds(22,25));  // Define custom pixel range with a name.

CHSV colorOne(0,222,255);  // Define a custom color.
CHSV colorTwo(82,222,255);  // Define a custom color.

//---------------------------------------------------------------
void setup() { 
  FastLED.addLeds<LPD8806, 11, 13, GRB>(leds, NUM_LEDS);
  FastLED.setBrightness(255);
}

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Leo_Bettinelli · April 2, 2016, 3:18pm

what do you think? I have it running like this:

#include “FastLED.h”
#define NUM_LEDS 5
CRGB leds[NUM_LEDS];

uint8_t hue0 = 0;
uint8_t hue1 = 72;
uint8_t hue2 = 144;
uint8_t hue3 = 216;
uint8_t hue4 = 288;

void setup() {
delay(3000);
FastLED.addLeds<UCS2903, 49>(leds, NUM_LEDS);
}

void loop() {
led0();
led1();
led2();
led3();
led4();
FastLED.show();
}

void led0() {
EVERY_N_MILLISECONDS(10)
leds[0] = (CHSV(hue0++, 255, 255));
}

void led1() {
EVERY_N_MILLISECONDS(100)
leds[1] = (CHSV(hue1++, 255, 255));
}

void led2() {
EVERY_N_MILLISECONDS(200)
leds[2] = (CHSV(hue2++, 255, 255));
}

void led3() {
EVERY_N_MILLISECONDS(500)
leds[3] = (CHSV(hue3++, 255, 255));
}

void led4() {
EVERY_N_MILLISECONDS(1000)
leds[4] = (CHSV(hue4++, 255, 255));
}

marmil · April 2, 2016, 3:32pm

I think the EVERY_N_MILLISECONDS lines need to be inside the main loop. (I think @Mark_Kriegsman said that.) Also note the use of braces { } around the code that will run every N milliseconds. But otherwise, yes, I think you got it.

Kelvin_Mead · April 9, 2016, 11:51am

ack… EVERY_N_MILLISECONDS is built into fastled to replace (help) with the currentmillis()-previousmillis()?

dammit… ive been wasting a lot of time getting my projects to run if i can just use this!

marmil · April 9, 2016, 9:59pm

Ack, my brain must have slipped the other day. Obviously using EVERY_N* works fine outside of the main loop and in a subroutine, as I did that in my first example provided above. (It must have been something else I remember Mark saying needed to be inside the main loop.) Did you get it all working @Leo_Bettinelli ? I would still suggest the use of the braces though, so for your example:
void led0() {
EVERY_N_MILLISECONDS(10) { // <–don’t forget these braces
leds[0] = (CHSV(hue0++, 255, 255));
} // <–every_n closing brace
}

@Kelvin_Mead , yes the addition of EVERY_N* to FastLED is wonderful. It definitely simplifies the code, and also makes it much more readable.

Leo_Bettinelli · April 10, 2016, 10:32am

ey marc!

it obviously work outside of the main loop because it was already working for me when you mentioned that it needs to be inside of the loop.

I take your advice on braces!

super thank you!