ColorTemperature.ino

[Fdesign]

Hi,
I'm quite new to working with LED strips. And currently trying out the ColorTemperature.ino example.
For some reason only the first led of the strip reacts to this code and the rest remain off.
It's probably a simple explanation but i can't figure it out.

Here is the code (and yes i'm only using a small piece of my led strip with just 2 LEDS) I tried if the second led works (which it does) so that's not the problem.

Code:

#include <FastLED.h>

#define LED_PIN 7

// Information about the LED strip itself
#define NUM_LEDS 2
#define CHIPSET WS2812
#define COLOR_ORDER GRB
CRGB leds[NUM_LEDS];

#define BRIGHTNESS 128

// FastLED v2.1 provides two color-management controls:
// (1) color correction settings for each LED strip, and
// (2) master control of the overall output 'color temperature'
//
// THIS EXAMPLE demonstrates the second, "color temperature" control.
// It shows a simple rainbow animation first with one temperature profile,
// and a few seconds later, with a different temperature profile.
//
// The first pixel of the strip will show the color temperature.
//
// HELPFUL HINTS for "seeing" the effect in this demo:
// * Don't look directly at the LED pixels. Shine the LEDs aganst
// a white wall, table, or piece of paper, and look at the reflected light.
//
// * If you watch it for a bit, and then walk away, and then come back
// to it, you'll probably be able to "see" whether it's currently using
// the 'redder' or the 'bluer' temperature profile, even not counting
// the lowest 'indicator' pixel.
//
//
// FastLED provides these pre-conigured incandescent color profiles:
// Candle, Tungsten40W, Tungsten100W, Halogen, CarbonArc,
// HighNoonSun, DirectSunlight, OvercastSky, ClearBlueSky,
// FastLED provides these pre-configured gaseous-light color profiles:
// WarmFluorescent, StandardFluorescent, CoolWhiteFluorescent,
// FullSpectrumFluorescent, GrowLightFluorescent, BlackLightFluorescent,
// MercuryVapor, SodiumVapor, MetalHalide, HighPressureSodium,
// FastLED also provides an "Uncorrected temperature" profile
// UncorrectedTemperature;

#define TEMPERATURE_1 Tungsten100W
#define TEMPERATURE_2 OvercastSky

// How many seconds to show each temperature before switching
#define DISPLAYTIME 10
// How many seconds to show black between switches
#define BLACKTIME 1

void loop()
{
// draw a generic, no-name rainbow
static uint8_t starthue = 0;
fill_rainbow( leds + 5, NUM_LEDS - 5, --starthue, 20);

// Choose which 'color temperature' profile to enable.
uint8_t secs = (millis() / 1000) % (DISPLAYTIME * 2);
if( secs < DISPLAYTIME) {
FastLED.setTemperature( TEMPERATURE_1 ); // first temperature
leds[0] = TEMPERATURE_1; // show indicator pixel
} else {
FastLED.setTemperature( TEMPERATURE_2 ); // second temperature
leds[0] = TEMPERATURE_2; // show indicator pixel
}

// Black out the LEDs for a few secnds between color changes
// to let the eyes and brains adjust
if( (secs % DISPLAYTIME) < BLACKTIME) {
memset8( leds, 0, NUM_LEDS * sizeof(CRGB));
}

FastLED.show();
FastLED.delay(8);
}

void setup() {
delay( 3000 ); // power-up safety delay
// It's important to set the color correction for your LED strip here,
// so that colors can be more accurately rendered through the 'temperature' profiles
FastLED.addLeds<CHIPSET, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS).setCorrection( TypicalSMD5050 );
FastLED.setBrightness( BRIGHTNESS );
}

[PaulRB]

For some reason only the first led of the strip reacts to this code and the rest remain off.
It's probably a simple explanation but i can't figure it out.

Can you say which line of your code you think would set anything other than the first led? We can explain why it isn't, if you can't figure that out.

PS. Did you notice the smiley in your code above? That happens when you don't read the forum guide before posting. Please read that and modify your original post to fix it.

[bezelsanddisplays]

Just a brief look at the code suggests this line:
leds[0] = TEMPERATURE_1;
will light the first LED

For FastLED the number in [] is the LED number to light up.
Just a suggestion but as an diagnostic step, try changing the [0] to [1] to see if the second LED lights up.

[johnwasser]

Since NUM_LEDS is 2, this line is likely to cause problems:

fill_rainbow( leds + 5, NUM_LEDS - 5, --starthue, 20);