Hi All. I have a LED strip(WS2801) of 50 LED's.

Wayne_van · October 28, 2015, 5:41am

Hi All.
I have a LED strip(WS2801) of 50 LED’s. I am searching for a code which light up a LED at the beginning of the strip and sends it down to the end, once it reaches the end it must stay “ON” then send the next dot (Fill up the strip) once full switch them off. (I am using an Arduino MEGA 2560).

Thanks in advance for your help.

Mark_Kriegsman · October 28, 2015, 9:44am

Hi! What code do you have so far? How far have you gotten with this?

And do you have an idea of what you want to happen once the lights are “full”? switch them off and then what? Wait for a button push? Or just start again?

Sebastian_Stuecker · October 28, 2015, 2:46pm

I put together a trivial example which just restarts once filled.

http://pastebin.com/F0pJwhPu

Possible improvements:

rotating hue
let something fancy happen in the filled part
add a faiding tail to the moving pixel
multiple pixel, sent from the start randomly or with fixed spacing
pixel starting at more than one position (e.g. from 2 sides
reverse direction
etc. etc

Thomas_Runge · October 28, 2015, 3:10pm

It would be easier if you could provide a full working example, so volunteers could just copy and paste and get it running. Some comments in your source wouldn’t hurt either.

Sebastian_Stuecker · October 28, 2015, 3:34pm

sure - here you go

http://pastebin.com/Cg7Q1NAt

Sebastian_Stuecker · October 28, 2015, 5:17pm

An extended version with bugfixes, rotating color and a fading tail.

http://pastebin.com/atSp12Ai

Wayne_van · October 28, 2015, 11:21pm

Thank you all so much! its just perfect.

marmil · October 28, 2015, 11:25pm

Here’s a version I made:

github.com

marmilicious/FastLED_examples/blob/master/fill_up_strip.ino

// fill_up_strip
// Moving pixels "fill" up strip, then clear and start again.
// The "filling" effect can be visually adjusted and slowed down near end.
// Has not been tested with a large number of pixels.
//
// Marc Miller,  Oct 2015
//---------------------------------------------------------------

#include "FastLED.h"
#define LED_TYPE LPD8806
#define DATA_PIN 11
#define CLOCK_PIN 13
#define NUM_LEDS 32
#define COLOR_ORDER GRB
#define MASTER_BRIGHTNESS 255
CRGB leds[NUM_LEDS];
float delta;
uint8_t count = 0;
uint8_t hue = random8();         // Pick a random color.
uint8_t sat = random8(160,255);  // Pick a random saturation in range.

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I experimented with a way to slow the filling effect down at the very end by using a delay that exponentially increases. The delay values that control this slowing can be tweaked based on the number of pixels in your strip and what looks good to you visually. But I’m not really sure if it will work for a large NUM_LEDS as I only tested with 32 pixels.

Wayne_van · October 30, 2015, 2:24am

Thanks again for all you help. Got a whole lot more than i expected!