GetColor

Reads the current value of the HiTechnic Color sensor

Contents

Syntax

[index r g b] = GetColor(port)

[index r g b] = GetColor(port, handle)

Description

degree = GetColor(port) returns the index color value and the RGB-values of the HiTechnic Color sensor. The color index for mode=0 and mode=1 corresponds to the following table, but the color values don't be pure RGB-values. Tests give best results for RGB-colors in brackets:

%	    0 = black (0-0-0)
%	    1 = violet
%	    2 = purple
%	    3 = blue
%	    4 = green
%	    5 = lime
%	    6 = yellow
%	    7 = orange
%	    8 = red
%	    9 = crimson
%	    10 = magenta
%	    11 to 16 = pastels
%	    17 = white

The color index (0..63) for mode=2 and mode=3 will return a 6 bit color index number, which encodes red in bit 5 an 4, green in bit 3 and 2 and blue in bit. It gives good results to identify a color by one value.

The RGB-Values will be returned depending on the mode parameter mode = 0 : RGB = the current detection level for the color components red, green and blue in an range of 0 to 255 mode = 1 : RGB = the current relative detection level for the color components red, green and blue in an range of 0 to 255. The highest value of red, green and blue is set to 255 and the other components are adjusted proportionally. mode = 2 : RGB = the analog signal levels for the three color components red, green and blue with an accurancy of 10 bit (0 to 1023). mode = 3 : RGB = the current relative detection level for the color components red, green and blue in an range of 0 to 3.

The given port number specifies the connection port. The value port can be addressed by the symbolic constants SENSOR_1 , SENSOR_2, SENSOR_3 and SENSOR_4 analog to the labeling on the NXT Brick.

For more complex settings the functions NXT_LSRead and NXT_LSWrite can be used.

The last optional argument can be a valid NXT handle. If none is specified, the default handle will be used (call COM_SetDefaultNXT to set one).

Example

   OpenColor(SENSOR_4);
   [index r g b] = GetColor(SENSOR_4, 0);
   CloseSensor(SENSOR_4);

See also

OpenColor, CalibrateColor, CloseSensor, COM_ReadI2C,

Signature

Published with wg_publish; V1.0