# I'm thinking of using 30/meter LEDs on the outside of my house,

I’m thinking of using 30/meter LEDs on the outside of my house, but I’d like to test brightness/coverage, etc, before buying anything. At the moment, I have a 60/meter LED strip. Is there an EASY way to get the FastLED demo reel to run on every second LED? If not, no problem, I’ll write some other code to git 'er done – just thought there might a simple line of code (that I’m unaware of) to add. Have a great and bright lit week all!

Unless you want a higher density 30 LED representation, no.

You’d have to write something to manipulate the LED placement.

Maybe define a second temp strip, so you would have something like:

// Define the array of leds
CRGB leds[NUM_LEDS];
CRGB leds_temp[NUM_LEDS/2];

Operate on the temp strip and then call a function that copies the temp values to every second LED on the 60/m strip. Then call FastLED.show().

alternatively, just put every second LED to black before calling FastLED.show

for (int i=0;i<NUM_LEDS;i+=2) leds[i]=CRGB::Black;

Thanks for the thoughts! I think I’ll just define some arrays and call up different colors at different brightnesses. That should give me enough of an idea to decide whether to move forward or not. (TRANSLATION: Get my wife’s approval).

I’ve done this before and just used something along the lines of this - it’s just testing so i didn’t worry about the hackiness. - stick it in before show()

for(int i=0;i<NUM_LEDS;i++){
if(i%2==0){
leds[i] = CRGB(0,0,0);
}
}

Replace every
leds[ SOMETHING ]
with
leds[ (SOMETHING) * 2 ]

(And make sure you adjust NUM_LEDS by half, but leave the LED array defined at full size!)

Please post pictures when you’re done. I’ve been wanting to do a house installation of digital LEDs but can’t really imagine and justify the costs for the strips lol.

Also check out (weatherproof!) pixel strings like these: http://m.aliexpress.com/item/1032319604.html

@Mark_Kriegsman Thanks! I’ll give that code a go. And thanks for the LED suggestion. I think I can just make clips for the LED strip ina tube though. The link you shared would require more construction to hold the LEDs in place and hide the wiring.

@Jared_Kotoff I hear ya! I’ll need at least 40 meters going for at least \$8/meter (on eBay) so that’s \$320 just in LEDs. Then there’s all the other wire, power sources, and the “brain” (probably Teensy 3.2).

If I decide to go ahead with the project, I’ll document the build somewhere so that it can be used as a reference.

I tried on the outside edge of the eaves, facing down, but wasn’t happy with the effect (to hidden and not enough ambient light). When I moved the strip to the inside edge, about an inch away from our stucco exterior, the strip lights up the wall nicely and then that gets reflected on the white aluminum soffit – and you can still see the individual LEDs. I just need to confirm that I (and my wife) will still like the effect with half the LED density.

@Sebastian_Stuecker I quickly plugged your code in and got exactly the results I needed. Thanks.