I have to make a chase down a lenght of LED and have found

Richard_Grogan · February 23, 2016, 12:59am

I have to make a chase down a lenght of LED and have found this in the demo code.
void sinelon()
{
// a white dot sweeping back and forth, with fading trails
fadeToBlackBy( leds, NUM_LEDS, 30);
int pos = beatsin16(12,0,NUM_LEDS);
leds[pos] += CRGB::White;
}

Can this be made to travel in one direction only not back and forth as it currently does?
Any help apreciated

marmil · February 23, 2016, 1:47am

Here’s an example that might work for you.

github.com

marmilicious/FastLED_examples/blob/master/beat8.ino

//***************************************************************
// beat8 example.  Moves pixel position based on beat8.
//
// -Marc Miller, Jan 2016
// Updated Feb 2016 - made move speed and fade rate variables.
//***************************************************************

#include "FastLED.h"
#define LED_TYPE LPD8806
#define DATA_PIN 11
#define CLOCK_PIN 13
#define NUM_LEDS 32
#define COLOR_ORDER GRB
#define BRIGHTNESS 50
CRGB leds[NUM_LEDS];

uint8_t gHue = 0;  // Used to cycle through rainbow.
uint8_t moveSpeed = 6;  // Higher value moves pixel faster.
uint8_t fadeRate = 80;  // Use lower value to give a fading tail.

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marmil · February 23, 2016, 1:54am

Also, try out the “FirstLight” example that’s included with FastLED.

Richard_Grogan · February 23, 2016, 6:32am

Thanks Marc
I will give them a try

Erin_St_Blaine · March 13, 2017, 10:57pm

@marmil is there a way to “freeze frame” this code? I want to be able to run it for a few seconds and then have it freeze at a random moment.

marmil · March 13, 2017, 11:46pm

@Erin_St_Blaine Freeze permanently, or for awhile and then run again for a random time?

marmil · March 14, 2017, 7:51am

Here’s an experiment for you @Erin_St_Blaine
http://pastebin.com/tc4CTCCr
I’m guessing you’re either going to use this in some awesome version of musical chairs, or for a 10 foot tall digital raffle wheel.

Erin_St_Blaine · March 14, 2017, 2:47pm

heh. You’re close! I’m gonna tell fortunes. Thanks so much, I’ll play with this!!

marmil · March 14, 2017, 9:00pm

@Erin_St_Blaine My beat8_plus_random_freeze.ino example does work. But I just realized I probably made it WAY more complicated then needed. (Isn’t it funny/great/trippy when you look at something again and see a much simpler solution?) In my original beat8.ino example above, if you want it to stop moving change the moveSpeed variable to… zero! lol.

It could be suddenly changed to zero or even ramp down to zero via code after a random time. Prior to stopping the moveSpeed could also be modulated with sin8, or some sort of external sensor (yeah!). I leave it to your wonderful creative side as to how to do that.