Hi, I need a bit of advice.

Tomas_Barta · May 24, 2017, 10:40am

Hi, I need a bit of advice. I am a newbie to FastLED and Arduino. I need to blink specific leds on my strip with specific frequency at the same time. E.g. while the first led is blinking 1/s, the second led 2/s. Is there any function in FastLed dealing with this? I did some research, but without any success. Thanks a lot.

FastLed 3.1.3, Arduino UNO, Win 10, leds: WS2812B

Jason_Coon · May 24, 2017, 1:56pm

Welcome! Try out beatsin8(beatsPerMinute, minimumValue, maximumValue):

led[0] = CHSV(hue, saturation, beatsin8(60, 0, 255));
led[1] = CHSV(hue, saturation, beatsin8(120, 0, 255));
…

More info:
https://plus.google.com/112916219338292742137/posts/boFjiQNiMAz

github.com

FastLED/FastLED/blob/a5ed0960b1f43feaa37f3ba88745a79be28c16bf/lib8tion.h#L811


//                    rising up again, etc..  The output of this function
//                    is suitable for feeding directly into sin8, and cos8,
//                    triwave8, quadwave8, and cubicwave8.
//       beat16( BPM ) returns a 16-bit value that cycles 'BPM' times
//                    per minute, rising from 0 to 65535, resetting to zero,
//                    rising up again, etc.  The output of this function is
//                    suitable for feeding directly into sin16 and cos16.
//       beat88( BPM88) is the same as beat16, except that the BPM88 argument
//                    MUST be in Q8.8 fixed point format, e.g. 120BPM must
//                    be specified as 120*256 = 30720.
//       beatsin8( BPM, uint8_t low, uint8_t high) returns an 8-bit value that
//                    rises and falls in a sine wave, 'BPM' times per minute,
//                    between the values of 'low' and 'high'.
//       beatsin16( BPM, uint16_t low, uint16_t high) returns a 16-bit value
//                    that rises and falls in a sine wave, 'BPM' times per
//                    minute, between the values of 'low' and 'high'.
//       beatsin88( BPM88, ...) is the same as beatsin16, except that the
//                    BPM88 argument MUST be in Q8.8 fixed point format,
//                    e.g. 120BPM must be specified as 120*256 = 30720.
//
//  BPM can be supplied two ways.  The simpler way of specifying BPM is as

Tomas_Barta · May 24, 2017, 3:29pm

Many thanks, this is suitable for examples I have provided, however I also need to blink a led for 1s (let’s say) every 5 minutes.
Therefore the code similar to:
leds[0] = CRGB::White; FastLED.show(); delay(1000);
leds[0] = CRGB::Black; FastLED.show(); delay(300000);

but indeed it doesn’t work for many more leds to be switched on at the same time, as there is delay. Ideally, I need something like:

leds[0] = some_function_that_switches_on_and_off_led(color, miliseconds, color,miliseconds);
leds[1] = some_function_that_switches_on_and_off_led(color, miliseconds, color,miliseconds);

i.e. leds[0] will blink every second for one second …and leds[90] will blink every 5 minutes for one second.

Any suggestion appreciated.
Thank you

Jason_Coon · May 24, 2017, 3:48pm

Try the EVERY_N macros:

EVERY_N_MILLIS(30) { leds[0] = CRGB::White; }
EVERY_N_SECONDS(2) { leds[0] = CRGB::White; }
EVERY_N_MINUTES(5) { leds[0] = CRGB::White; }
EVERY_N_HOURS(1) { leds[0] = CRGB::White; }

https://github.com/FastLED/FastLED/blob/master/lib8tion.h#L1082

Andrew_Tuline · May 24, 2017, 6:18pm

Jason’s got it right, and please don’t use delay statements or they will wreck your timing and render any inputs (buttons, etc) useless.

Tomas_Barta · May 25, 2017, 7:14am

Thank you guys.

I think I’m on the right way. I have tried:
EVERY_N_SECONDS(1000) { leds[0] = CRGB::White; };
FastLED.show();
but led keeps switched on and not blinking, so I changed the code to:
leds[0] = CRGB::Black;
FastLED.show();
EVERY_N_SECONDS(1) { leds[0] = CRGB::White; }
FastLED.show();

it works pretty well, but I cannot control time of led, when is switched on. It flashes every second for cca 1ms (?).
I have an idea to test millis timing using a bit dirty way:
if (millis()%1000==0){
leds[0] = CRGB::White;
FastLED.show();
}
if (millis()%3010==0) {
leds[0] = CRGB::Black;
FastLED.show();
}

it works very well. Hope this “dirty” way is OK and the code will fit to memory. I’m using 96 leds and to address each individually will consume much of memory. I have to test it.

Anyway thank you for your suggestions.

Jason_Coon · May 25, 2017, 2:27pm

Nothing at all wrong with that way, good work!