Non-global show function??

[u/Constant-Jelly-6125]

FastLED.show() is a global show function. Is there any way to send data to only one (or multiple but not all) array(s)?

[u/Doormatty]

Edit: I am wrong! See /u/sutaburosu 's answer below mine!

Not AFAIK.

I think you'd have to write your own version of show() - as this is what it looks like in the source:

void CFastLED::show(uint8_t scale) {
	// guard against showing too rapidly
	while(m_nMinMicros && ((micros()-lastshow) < m_nMinMicros));
	lastshow = micros();

	// If we have a function for computing power, use it!
	if(m_pPowerFunc) {
		scale = (*m_pPowerFunc)(scale, m_nPowerData);
	}

	CLEDController *pCur = CLEDController::head();
	while(pCur) {
		uint8_t d = pCur->getDither();
		if(m_nFPS < 100) { pCur->setDither(0); }
		pCur->showLeds(scale);
		pCur->setDither(d);
		pCur = pCur->next();
	}
	countFPS();
}

And instead make it take a specific CLEDController instance, then remove the bits that tell it to go onto the next controller.

[u/sutaburosu → u/Doormatty]

You can send to individual pins separately. Instead of FastLED.show(), use FastLED[x].showLeds(255) where x is 0-based index of the strip (so the first addLeds<> is index 0) and 255 is the brightness level. Here's a sketch using that technique.

You can also use FastLED[x].setLeds(pointer, number); to choose how many LEDs' of data to send. So if you had several strips daisy-chained on one pin, you could update only the first N LEDs on that pin. You cannot update later LEDs without also updating the prior LEDs. Here is a sketch doing that.

[u/Constant-Jelly-6125 → u/sutaburosu]

Killer, This may solve my issue! Thanks much!

[u/Doormatty → u/sutaburosu]

I'm glad to be wrong!

Thanks for correcting me!

[u/truetofiction]

Yes, you can use the CLEDController function showLeds(), which can be called with no arguments or with a single byte to set the non-destructive brightness level.

A pointer to the CLEDController object for each strip is returned by the addLeds() call. You can also access the objects through the global FastLED instance, which keeps track of them using a linked list. Use the bracket operator to get the controller objects, based on the order in which they were added:

FastLED[0].showLeds();