Red Light, Green Light

Introduction

Use the ||sensors:pause until color sensor detected|| block to play Red Light, Green Light with your LEGO® MINDSTORMS® Education EV3 robot!

Brick simulation with color sensor and motors

Step 1

Open the ||sensors:Sensors|| Toolbox drawer. Drag out 2 ||sensors:pause until color sensor detected|| blocks onto the Workspace, and drop them into the ||loops:forever|| loop.

forever(function () { 
    sensors.color3.pauseUntilColorDetected(ColorSensorColor.Blue) 
    sensors.color3.pauseUntilColorDetected(ColorSensorColor.Blue) 
})

Step 2

In the first ||sensors:pause until color sensor detected|| block, use the second drop-down menu to select the Green color. In the second ||sensors:pause until color sensor detected|| block, use the second drop-down menu to select the Red color.

Color selection dropdown

forever(function () { 
    sensors.color3.pauseUntilColorDetected(ColorSensorColor.Green) 
    sensors.color3.pauseUntilColorDetected(ColorSensorColor.Red) 
})

Step 3

Open the ||motors:Motors|| Toolbox drawer. Drag out a ||motors:tank motors|| block onto the Workspace, and drop in between the ||sensors:pause until color sensor detected|| blocks.

forever(function () { 
    sensors.color3.pauseUntilColorDetected(ColorSensorColor.Green) 
    motors.largeBC.tank(50, 50) 
    sensors.color3.pauseUntilColorDetected(ColorSensorColor.Red) 
})

Step 4

Open the ||motors:Motors|| Toolbox drawer. Drag out a ||motors:stop all motors|| block onto the Workspace, and drop it in after the second ||sensors:pause until color sensor detected|| block in the ||loops:forever|| loop.

forever(function () { 
    sensors.color3.pauseUntilColorDetected(ColorSensorColor.Green) 
    motors.largeBC.tank(50, 50) 
    sensors.color3.pauseUntilColorDetected(ColorSensorColor.Red) 
    motors.stopAll() 
})

Step 5

Now, plug your EV3 Brick into the computer with the USB cable, and click the Download button at the bottom of your screen. Follow the directions to save your program to the EV3 Brick.

Attach a Color Sensor to Port 3 and attach your EV3 Brick to a driving base with Large Motors attached to Ports B and C. See the building instructions for: Driving Base with Color Sensor Forward. Test your program by putting a green or red piece of paper or LEGO brick in front of the Color Sensor.