Hello People I'm having great trouble trying to use a potentiometer to control the brightness

Christopher_Bennett · August 1, 2015, 9:06pm

Hello People

I’m having great trouble trying to use a potentiometer to control the brightness of my WS2811 LED Strips with an Arduino Uno.

My main problem is that the LED strip I am using is White only, not RGB. All I want to do is use them for lighting in my room and to be able to control the brightness with the potentiometer. Nothing I do seems to work, probably because it is relaying RGB information. This is the code I have been using without Success: https://gist.github.com/hsiboy/11545fd0241ab60b567d
I just removed the Colour and Speed Part.
The potentiometer is working, as i have tested it sending data through the serial connected to A0, so the problem doesn’t lie there.

Hopefully someone can help me!
Thanks

William_Blanton · August 1, 2015, 9:10pm

Maybe try setting leds[i] = CHSV(mappedHue, 255, 255);

All to the mappedHue.

William_Blanton · August 1, 2015, 9:12pm

255,255,255 is bright white 128,128,128 is half bright

Christopher_Bennett · August 1, 2015, 10:32pm

Thanks for the Reply
Do you mean map the colour pin to the same as the brightness pin meaning it will change all three 255,255,255 values up and down?
I have tried this, but instead of brightness I just get different rates of flickering.
But if I just use a basic code, setting just the colour of the LED, and I input 255,255,255 it is bright white, and if I input 128,128,128, its half as bright, like you said. I just can’t find away to automate this with the Potentiometer!

Daniel_Garcia · August 1, 2015, 11:23pm

You just need something like what’s in here, I suspect:

gist.github.com

https://gist.github.com/focalintent/10d12198d5b1c1d69144

gistfile1.md

```C++
void loop() {
  int mappedValue = map(analogRead(brightnessInPin), 0, 1023, 0, 255);

  // set the brightness 
  FastLED.setBrightness(constrain(mappedValue, MIN_BRIGHTNESS, MAX_BRIGHTNESS));

  FastLED.showColor(CRGB::White);
}
```

just read the potentiometer to get your brightness value, call FastLED.setBrightness with that value, then just show the color white on all your strips.