Can the color sensor detect orange?

[Roy Toren]

Hi,

I need to detect the color orange, and the color mode does not recognise it, it reads orange as red which is problematic.
Is there a way to change it.

Thank you,

[Tcm0]

You can try to go by reflected light or the RGB mode (http://www.monobrick.dk/MonoBrickFirmwareDocumentation/class_mono_brick_firmware_1_1_sensors_1_1_r_g_b_color.html).

[Anders Søborg]

Hi

The page Max is referring to is the NXT color sensor. The EV3 color documentation can be found here

/Anders

[Tcm0]

Sorry, didn’t know that the NXT had RGB mode. In that case the reflected light or the RGB mode (if it’s avaible for the EV3 color sensor) should be your choice.

[Roy Toren]

I have already tried th reflected light in the color sensor example, it didnt work.

As for the RGB do I need a different sensor for that?
I have these two:

• This reply was modified 10 years, 3 months ago by Roy Toren.

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[Roy Toren]

The other sensor is this one:
(cant upload more then 512 KB :|)

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[Jacek S]

Hi,

Any progress? I trying to solve the same problem using the ev3 sensor.
I know it is possible with the new lego firmware 1.06H. Sensor can be switched into RGB mode.

Question for Anders: Which version of lego firmware is the base for the monobrick firmware?

Thanks,
Jacek

[Anders Søborg]

Hi

I will have a look at the raw data from the sensor to see if it has RGB values (to be honest I can’t remember if this is the case), but as you already point out it might not be available since our image is based on an older version of the LeJos image. But do you actually need the RGB values? the raw value should be good enough. You can see more here

/Anders

[Jacek S]

Hi,

I need RGB values to convert to HSV. This is the way that colors can be determined easily.
I have made modification to the firmware, and it is working for me. Now I can easily detect orange and other colors.

I added support for uart.mode4 to EV3ColorSensor.cs:

       
  public RGBColor ReadRGB()
  {
      if (uartMode != UARTMode.Mode4) Mode = ColorMode.RGB;
      byte[] rawBytes = ReadBytes(6);
      return new RGBColor(rawBytes[0], rawBytes[2], rawBytes[4]);
  }

[Anders Søborg]

Hi there

Amazing – could you please add a pull request (so you can get credit) so this can be part of the next release. Thanks

/Anders

[Jacek S]

Ok I will add. Thanks

[Auctor137]

Hello Jacek,

could you please tell me how to detect orange with your solution ?
I’m using a EV3 Colorsensor.

I’ve tried a bit with the code you have posted and checked the library page

but i don’t know how to write the code properly.

auctor

[Auctor137]

Hi everybody,

I’m a litte bit confused.. the new EV3 Colorsensor is not able to read RGB ? Why would LEGO do that?
I’ve tried this Code out of the new Tutorial from Max Mustermann, but with the EV3 Sensor it doesn’t work.
Red 0
Green 0
Blue 0
all the time.

using System;
using System.Threading;
using MonoBrickFirmware.Sensors;
using MonoBrickFirmware.Movement;
using MonoBrickFirmware.Display;
using MonoBrickFirmware.UserInput;

namespace farbsensor
{
    class farbsensor
    {
        static void Main(string[] args)
        {
            EV3ColorSensor farbsens = new EV3ColorSensor(SensorPort.In1);
            
            bool abfrage = true;
            string rotwert, gruenwert, blauwert;

            RGBColor RGBFarben = new RGBColor(0, 0, 0);
            ButtonEvents buts = new ButtonEvents();

            buts.EscapePressed += () => 
            { abfrage = false; };

            while (abfrage == true)
            {
                rotwert = Convert.ToString(RGBFarben.Red);
                LcdConsole.WriteLine("Rot :" + rotwert);

                gruenwert = Convert.ToString(RGBFarben.Green);
                LcdConsole.WriteLine("Gruen :" + gruenwert);

                blauwert = Convert.ToString(RGBFarben.Blue);
                LcdConsole.WriteLine("Blau :" + blauwert);
                Thread.Sleep(2000);
            }
            LcdConsole.WriteLine("###############");
            LcdConsole.WriteLine("PROGRAMMENDE...");
            Thread.Sleep(3000);

        }
    }
}

#EDIT
I forgot
RGBFarben = farbsens.ReadRGBColor();
infront of the “while-loop”, but farbsens does not have the function ReadRGBColor(), how can i do it?

• This reply was modified 10 years ago by Auctor137.
• This reply was modified 10 years ago by Auctor137.

[Jacek S]

Hi Auctor,

You need to compile firmware lib from the master branch. Because I added this functionality a week ago.
Then this should work:

            EV3ColorSensor colorSensor = new EV3ColorSensor(SensorPort.In2);
            RGBColor rgbColor = colorSensor.ReadRGB();
            Color color = Color.FromArgb(rgbColor.Red, rgbColor.Green, rgbColor.Blue);
            var hue = (int) color.GetHue();
            var bright = (int) (color.GetBrightness()*100);

Then look: http://en.wikipedia.org/wiki/Hue

[Auctor137]

Hi Jacek,

thanks, looking forward to use this!
But I really don’t know what to do, I’m not a a professional programmer..

Could you tell me how to compile the firmwarelib from the master branch and use your solution?

I’m using Visual Studio 2012 C# with Windows 7

• This reply was modified 10 years ago by Auctor137.

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