Colors for 32 X 32 RGB led martix board

Hello im using an 32 X 32 rbg led board with my arudino uno and my question is, is there a way to get different colors other than red,green,blue,white and like purple.... is there like any way to get grey or brown?

this is the code i use now to get different colors:

matrix.drawPixel(7, 13, matrix.Color333(7, 0, 0));

-Thanks

We can only answer that question if we know exactly what sort of RGB matrix you have. You need one that allows not only on / off control but also brightness control.

Hi, what kind of matrix, which code, which library?

Do the leds have their own controller or is it just a plain matrix?

In case you can already address single pixels a color circle would be a place to start.

Here a chart with values for r, g and b.

Saturation and brightness control are the next steps. (shifting a color towards white or black)

Grey is mixed by equal small amounts of r, g and b (assuming you have a white balanced display).

For brown have a look here.

Good luck!

For brown have a look here.

Note I have found it impossible to get a brown from an RGB LED, and I have tried many systems including a pot for each of the colours. Maybe it is the sort of LED I have.

Note I have found it impossible to get a brown from an RGB LED

It is hard but not impossible. The main problem appears to be the fine alignment of the balance of the 3 colors.

8 bit resolution per channel is usually not enough for that. Or you just get one brown tone which turnes red when dimming down.

So a solution is to run your own software PWM or a dithering to increase the color space. If you apply that the the lowest quarter of the brightness it is enough - there is the biggest difference between the linear build in PWM of the led controller and the logarithmical light perception of the human eye.

Also some colors only show up properly hehind a diffusor / reflector.

I wasted hours starring directly into leds until I realized that the color a wanted was on the white wall reflected and looked exactely as it should...

Since that I'm a fan of translum materials for diffusion.

oh sry im using a 32 X 32 RGB led Matrix made by adafruit. and the librarys are #include <Adafruit_GFX.h> // Core graphics library
#include <RGBmatrixPanel.h>

also here is a little bit of my code if it helps:

#define CLK 8
#define OE 9
#define LAT 10
#define A A0
#define B A1
#define C A2
#define D A3

RGBmatrixPanel matrix(A, B, C, D, CLK, LAT, OE, false);

void setup(){
matrix.begin();

}

void loop() {

//matrix.fillRect(0, 0, 32, 32, matrix.Color333(0, 7, 7));

matrix.drawLine(0, 0, 31, 0, matrix.Color333(7, 7, 7));
matrix.drawLine(0, 1, 31, 1, matrix.Color333(7, 7, 7));
matrix.drawLine(0, 2, 14, 2, matrix.Color333(7, 7, 7));
matrix.drawLine(18, 2, 31, 2, matrix.Color333(7, 7, 7));

}

Helmuth - I was using 12 bits PWM and viewing the results through a styrene diffuser.

oh sry im using a 32 X 32 RGB led Matrix made by adafruit.

Which one, link please.

Ok, so basically you have only 4 bits per channel.

I recommend to get a Teensy and the SmartMatrix Shield which allows you to drive that matrix at 24 or even 36 bit color depth.

Louis has written a fancy binary code modulation for that matrix. Link.

FastLED supports that shield+matrix, too.

Are you using an AVR or an ARM processor?

@Grumpy_Mike: He means this product.
What was the precise problem with the color blending? No brown at all or too much drift towards one color?

@Mike: Sharp uses in TV Displays additional yellow subpixels for better brown, gold and skin tones.

edit: The surrounding matters too. Look at one of the brown squares for a while. Then focus on the other one.

In order to don’t influence you, I am not going to tell, what my brain does with the picture.

Do you know what I mean?

Ok, so basically you have only 4 bits per channel.

No I was driving each colour with 12 bits from a TLC5940.

Sharp uses in TV Displays additional yellow subpixels for better brown, gold and skin tones.

Yes I tried having a separate yellow LED as well as the RGB one.

The surrounding matters too.

Yes I know that as well.

I have been doing electronics since the 1960's.

Ok, so basically you have only 4 bits per channel.

No I was driving each colour with 12 bits from a TLC5940.

Sorry, I meant tharealdeal15 using the adafruit lib with that remark.

I have been doing electronics since the 1960’s.

Hey, my suggestions were not meant to be an offence Mike!
Basically your posts supported me a lot while stepping into the Arduino and electronics world. I started just 3 years ago and I read 1000s of your postings while I noticed, that you really know what you are talking about. And I like your humor and grumpiness! So at this point: Thanks for all you share here, Mike.

Back to the topic: You say you found it impossible, to get brown out of a RGB led. I say it is difficult. If I post RGB values I perceive as brown it has no meaning because we have different leds. If I post a photo of one of my setups we start talking about color calibration of cameras and monitors. So what can we do?

So what can we do?

Well you can tell me if you have actually got a convincing brown from an LED and if so what was the part number and I will see it I can reproduce it. :slight_smile:

Lets see if this is convincing:

Software: FastLED, 24 bit color, dithering on.

leds[i]  = CRGB( 139, 69, 8);
leds[i] %= 30;                         // scales down to 30/255

Hardware:

WS2812B behind a plexiglass diffusor

Result:

Both pictures were taken in the same room with the same available light, all auto corrections off, whitebalance locked.

LED light:

A sample from LEE Filters:

Thanks indeed this is brown. :slight_smile:

However my problem is that I want to make brown with the led and also other colours, in fact the colours of the resistor colour code, so having a brown gell is not an option.

Black is a problem that I solved by using a diffuse dark filter but it is all a bit unsatisfactory. I think my only soloution is to use an LCD colour display.

Sorry I seem to have hijacked this thread.

Sorry for my bad english but what means "brown gell"?

If I had to use LEDs to visualize resistor codes I would severe dim the plain colors for the same perceived intensity of all colors.

The best black I know comes from OLEDs. :sunglasses:

New thread about black and colors?

Gell is the short word for gellitiene filter, even though they are not made of that anymore it is the term used in theatre lighting ( I used to do that as well :slight_smile: )

Yes I am still waiting for the black LED.