Coding the VEX 123 Eye Sensor with VEXcode 123

The 123 Robot contains many sensors, including an Eye Sensor. The Eye Sensor on the 123 Robot can be coded using VEXcode 123.

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The following article will cover:


The Eye Sensor on the 123 Robot

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The 123 Robot has an Eye Sensor on the front that can detect if there is an object present, as well as detect color (red, green, or blue).


VEXcode 123 Blocks Used with the Eye Sensor

Detecting object presence blocks

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The [Drive until] and <Found object> blocks report if the Eye Sensor is close to an object or not.

<Detects color> block

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The <Detects color> block reports if the Eye Sensor detects the specified color.

(Brightness of) block

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The (Brightness of) block reports the brightness level as a percentage. This can be used to distinguish between light and dark objects and environments.

(Hue of) block

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The (Hue of) block reports a hue color value of an object. This can be useful when determining the colors of different objects.

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The (Hue of) block reports a hue value between 0 - 359 degrees.


Common Uses of the Eye Sensor

The Eye Sensor on the 123 Robot can be used in many ways. The 123 Robot can use the Eye Sensor to initiate a sequence of behaviors when it is in the correct place to do so. For example, the 123 Robot can drive forward until it detects that it is near an object, such as a wall or another 123 Robot, then turn around to not crash into it.

The 123 Robot can make decisions depending on if the Eye Sensor detects a blue object. This is useful if you want the 123 Robot to drive up to a specifically colored object, detect the color of objects as they pass by the sensor, or perform a certain behavior once a color is detected. In this example, if the Eye Sensor detects a blue object, the 123 Robot will turn right. If the Eye Sensor does not detect a blue object, the 123 Robot will turn left.

The 123 Robot can make decisions depending on if the Eye Sensor detects a bright or dark object. In this example, if the Eye Sensor detects a bright object, the 123 Robot will turn right. If the Eye Sensor does not detect a bright object, the 123 Robot will turn left.

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The 123 Robot can also report the hue color value of different objects. In this example, the hue value of a green 123 Robot will be reported. The Monitor Console can be used to see the hue value changing in real time, when the checkbox next to the (Hue of) block is selected.

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The value can then be compared to the hue chart.