Great library - very handy whilst working on this WS2801 project! I'm needing a

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1

Great library - very handy whilst working on this WS2801 project!

I’m needing a function to pull the R/G/B values directly out of the leds array so I can do some math on them. I’m trying to slow “grow” a chain of pixels, and although there is a “fade” function that cranks down values, I’m trying to write one that goes up.

Simple example:
leds[0]=5,5,5
leds[1]=10,10,10

I’m trying to grow the illumination from the values in leds[0] to leds[1] in a series of predetermined intervals (spec’d or calc’d; not sure which). It’s sure be handy to have a function similar to the color setting function:
leds[i].red = 50;

but where it would return the RGB value specified.

I’ve written a function to parse values from the HEX into RGB, but they write to global variables. My C-fu isn’t strong enough to write a proper function that returns the array to the calling function.

void fadecol(long fromCol, long toCol) {
int rfromCol = (fromCol >> 16) & 0xFF; //Parse out the RGB values of the FROM color
int gfromCol = (fromCol >> 8) & 0xFF;
int bfromCol = (fromCol >> 0) & 0xFF;

byte rtoCol = (toCol >> 16) & 0xFF; //Parse out the RGB values of the TO color
byte gtoCol = (toCol >> 8) & 0xFF;
byte btoCol = (toCol >> 0) & 0xFF;

Anybody mind throwing a bone my way so I can figure out a method to do this?

(ps: The C in the pixeltype.h is impressive. Much to grok, like “return *this;” Funky…)

2

you can access the rgb values directly, e.g. leds[0].r - you can also used 32 bit RGB values, e.g. leds[0] = 0x00FFFFFFL; https://github.com/FastLED/FastLED/wiki/Pixel-reference has some other examples.

Why work in hex when you can work in RGB?

You can also do math on the RGB values e.g. leds[1] = leds[0]; leds[1].addToRGB(5);

3

But… But… I checked and… GARH!
Another case of skipping over the obvious. My apologies for wasting your time.

One other thing: Trying to use an Interrupt to trigger an animation, which works FINE outside of the ISR. If I change my delays to delayMicroseconds, there’s not good reason why fastLED shouldn’t work when called as an ISR, right?

Thanks again!

4

You really want your ISRs to be as short as possible. Instead, i’d say do something like this:

static boolean bRun = false;

// I forget what avr ISRs look like
void myISR() {
// keep it short and fast
bRun = true;
}

void loop() {
if(bRun) {
bRun = false;
// do animation and call show
} else {
// maybe not even needed
delayMicroseconds(10);
}
}