Hi all, I'm working to create a lamp.

Harm_Aarts · July 29, 2017, 12:23pm

Hi all,

I’m working to create a lamp. This lamp consists of 30 1w LEDs. When turning a knob (pot) the lights flick on/off. Fully open all 30 LEDs would be one. I’ve tried with DMX and had limited success. Then a friend pointed out Fastled to me which seems almost what I want.
But I’m not interested in the RGB or strip capabilities. I just want to control 30 dimmable 12v LEDs.
The APA102 seems best but it is always integrated with a RGB LED. Is the a separate controller I can buy?
The WS2811 seems good but I worry about the flickering.

Thanks in advance!
Harm

Amanda_Walker · July 29, 2017, 2:10pm

There are white-only APA102 packages (example: http://www.ledlightinghut.com/apa102-white-digital-intelligent-led-strip.html).

Harm_Aarts · July 29, 2017, 2:49pm

Those I found but I don’t they put out enough lumens for my purpose. Fully lit the 30 lamps should be rather bright.
Also, the package isn’t as aesthetically pleasing.

marmil · July 29, 2017, 6:39pm

@Harm_Aarts Did you see this example?

github.com

FastLED/FastLED/blob/master/examples/AnalogOutput/AnalogOutput.ino

#include <FastLED.h>

// Example showing how to use FastLED color functions
// even when you're NOT using a "pixel-addressible" smart LED strip.
//
// This example is designed to control an "analog" RGB LED strip
// (or a single RGB LED) being driven by Arduino PWM output pins.
// So this code never calls FastLED.addLEDs() or FastLED.show().
//
// This example illustrates one way you can use just the portions 
// of FastLED that you need.  In this case, this code uses just the
// fast HSV color conversion code.
// 
// In this example, the RGB values are output on three separate
// 'analog' PWM pins, one for red, one for green, and one for blue.
 
#define REDPIN   5
#define GREENPIN 6
#define BLUEPIN  3

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You’ll need to use a power transistor in your setup similar to this.

Jeremy_Spencer · July 29, 2017, 10:14pm

These are the only separate controllers that I know of. They’re RGB but you could put different sets of white LEDs on each channel. You can also daisy chain them.
http://www.ebay.co.uk/itm/272682254000

marmil · July 29, 2017, 10:32pm

Actually now that you mention those @Jeremy_Spencer , it reminded me that I used some of these DMX voltage controllers a long time ago to control simple 12V strips and they worked fine. (Although I think the D+ and D- labels might have been reversed.)

@Harm_Aarts , if you want to control with DMX instead of an Arduino based controller, give something like that a try. You can find them on Ebay or Amazon too. Just be aware of how many Amps each channel can output and split your LED strips up as need.