Class ColorSensor

ev3dev2.sensor.lego.ColorSensor

LEGO EV3 color sensor.

Declaration

class ColorSensor(Sensor)

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Documentation

Methods

▶ def __init__(self, address=None, name_pattern=SYSTEM_DEVICE_NAME_CONVENTION, ...) override
inherited doc Spin through the Linux sysfs class for the device type and find a device that matches the provided name pattern and attributes (if any).
def __init__(
self,
address=None,
name_pattern=SYSTEM_DEVICE_NAME_CONVENTION,
name_exact=False,
**kwargs,
)
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This method overrides ev3dev2.sensor.Sensor.__init__.
Parameters:
class_name: class name of the device, a subdirectory of /sys/class.
For example, 'tacho-motor'.
name_pattern: pattern that device name should match.
For example, 'sensor*' or 'motor*'. Default value: '*'.
name_exact: when True, assume that the name_pattern provided is the
exact device name and use it directly.
keyword arguments: used for matching the corresponding device
attributes. For example, address='outA', or driver_name=['lego-ev3-us', 'lego-nxt-us']. When argument value is a list, then a match against any entry of the list is enough.
Example:
d = ev3dev.Device('tacho-motor', address='outA') s = ev3dev.Device('lego-sensor', driver_name=['lego-ev3-us', 'lego-nxt-us'])
If there was no valid connected device, an error is thrown.
▷ def ambient_light_intensity(self) @property
Ambient light intensity, as a percentage (0 to 100). Light on sensor is dimly lit blue.
@property
def ambient_light_intensity(self)
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▷ def blue(self) @property
Blue component of the detected color, in the range 0-1020.
@property
def blue(self)
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▶ def calibrate_white(self)
The RGB raw values are on a scale of 0-1020 but you never see a value
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anywhere close to 1020. This function is designed to be called when the sensor is placed over a white object in order to figure out what are the maximum RGB values the robot can expect to see. We will use these maximum values to scale future raw values to a 0-255 range in rgb().
If you never call this function red_max, green_max, and blue_max will use a default value of 300. This default was selected by measuring the RGB values of a white sheet of paper in a well lit room.
Note that there are several variables that influence the maximum RGB values detected by the color sensor - the distance of the color sensor to the white object - the amount of light in the room - shadows that the robot casts on the sensor
▶ def color(self) @property
Color detected by the sensor, categorized by overall value.
@property
def color(self)
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0: No color
1: Black
2: Blue
3: Green
4: Yellow
5: Red
6: White
7: Brown
▷ def color_name(self) @property
Returns NoColor, Black, Blue, etc
@property
def color_name(self)
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▷ def green(self) @property
Green component of the detected color, in the range 0-1020.
@property
def green(self)
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▶ def hls(self) @property
HLS: Hue, Luminance, Saturation
@property
def hls(self)
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H: position in the spectrum L: color lightness S: color saturation
▶ def hsv(self) @property
HSV: Hue, Saturation, Value
@property
def hsv(self)
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H: position in the spectrum S: color saturation ("purity") V: color brightness
▷ def lab(self) @property
Return colors in Lab color space
@property
def lab(self)
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▶ def raw(self) @property
Red, green, and blue components of the detected color, as a tuple.
@property
def raw(self)
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Officially in the range 0-1020 but the values returned will never be that high. We do not yet know why the values returned are low, but pointing the color sensor at a well lit sheet of white paper will return values in the 250-400 range.
If this is an issue, check out the rgb() and calibrate_white() methods.
▷ def red(self) @property
Red component of the detected color, in the range 0-1020.
@property
def red(self)
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▷ def reflected_light_intensity(self) @property
Reflected light intensity as a percentage (0 to 100). Light on sensor is red.
@property
def reflected_light_intensity(self)
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▷ def rgb(self) @property
Same as raw() but RGB values are scaled to 0-255
@property
def rgb(self)
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Inherited methods

Methods inherited from ev3dev2.sensor.Sensor:
address, bin_data, bin_data_format, command, commands, decimals, driver_name, mode, modes, num_values, units, value
Methods inherited from ev3dev2.Device:
__lt__, __repr__, __str__, device_index, get_attr_from_set, get_attr_int, get_attr_line, get_attr_set, get_attr_string, get_cached_attr_int, get_cached_attr_set, get_cached_attr_string, set_attr_int, set_attr_raw, set_attr_string