The Colour Sensor block gets data from the Colour Sensor. You can measure the colour or intensity of light and get a Numeric output. You can also compare sensor data to an input value and get a Logic (True or False) output.

See Using the Colour Sensor for more information about how the Colour Sensor works, the different modes, the data provided, and programming examples.

Tips and Tricks

The Colour Sensor block outputs data with a Data Wire See Using the Colour Sensor for other ways to use the Colour Sensor that don’t require a data wire.

Choose the Sensor Port and Mode

Port Selector

Mode Selector

Inputs

Outputs

Use the Port Selector on the top of the block to make sure that the sensor port number (1, 2, 3, or 4) matches the port on the EV3 Brick that the Colour Sensor is connected to.

Use the Mode Selector to select the mode for the block. The Inputs and Outputs available will change depending on the mode.

Measure - Colour

The Measure – Colour mode outputs the detected colour number in Colour.

Measure – Reflected Light Intensity

The Measure – Reflected Light Intensity mode outputs the light intensity in Measured Value.

See programming example 5 in Using the Colour Sensor.

Measure – Ambient Light Intensity

The Measure – Ambient Light Intensity mode outputs the light intensity in Measured Value.

Compare – Colour

In the Compare – Colour mode, you can select one or more colours in the Set of Colours. The Compare Result output will be True if the detected colour matches any of the selected colours. The detected colour is output to Measured Value.

Compare – Light Intensity

The Compare – Reflected Light Intensity and Compare – Ambient Light Intensity modes compare the detected light intensity to the Threshold Value using the selected Compare Type. The True/False result is output in Compare Result, and the detected light intensity is output in Measured Value.

Example 1

This program turns the Brick Status Light on in orange, and makes it pulse on and off whenever the Colour Sensor detects an ambient light intensity greater than 50.

Example 2

This program makes a robot drive until the Colour Sensor detects reflected light intensity < 50, or until motor B has turned 2000 degrees, whichever comes first.

Calibrate Modes

The Calibrate modes allow you to calibrate the Colour Sensor from within a program. You can also manually type in the minimum and maximum value the sensor should use.

Calibrate - Minimum

The Calibrate – Minimum mode allows you to specify the minimum light intensity in the Value input. After calibration, the Colour Sensor will report this light intensity as 0 or the value specified.

Calibrate - Maximum

The Calibrate – Maximum mode allows you to specify the maximum light intensity in the Value input. After calibration, the Colour Sensor will report this light intensity as 100 or the value specified.

Calibrate - Reset

The Calibrate – Reset mode restores the Colour Sensor calibration to its default state.

Inputs and Outputs

The inputs available for the Colour Sensor block will depend on the mode selected. You can enter the input values directly into the block. Alternatively, the input values can be supplied by Data Wire from the outputs of other Programming Blocks.

Input	Type	Allowed Values	Notes
Set of Colours	Numeric Array	Each element: 0 – 7	Selected colour(s) to test for in Compare – Colour mode: 0 = No Colour 1 = Black 2 = Blue 3 = Green 4 = Yellow 5 = Red 6 = White 7 = Brown
Compare Type	Numeric	0 - 5	0: = (Equal to) 1: ≠ (Not Equal to) 2: > (Greater than) 3: ≥ (Greater than or Equal to) 4: < (Less than) 5: ≤ (Less than or Equal to)
Threshold Value	Numeric	Any number	Value to compare sensor data to
Value	Numeric	0 – 100	Light intensity for Calibrate modes

The outputs available will depend on the mode selected. To use an output, use a Data Wire to connect it to another Programming Block.

Output	Type	Notes
Colour	Numeric	Detected colour number: 0 = No Colour 1 = Black 2 = Blue 3 = Green 4 = Yellow 5 = Red 6 = White 7 = Brown
Compare Result	Logic	True/False result of a Compare mode.
Measured Value	Numeric	The sensor data value used for a Compare mode.

Colour Sensor Block