Vision Sensor

Introduction

The Vision Sensor for VEX EXP detects and tracks colors and color codes. This allows the Vision Sensor to analyze its surroundings, follow objects, and react based on detected visual data.

Below is a list of all available blocks:

Actions — Capture data from the Vision Sensor for a selected object type.

• take vision snapshot — Captures a snapshot using a selected Vision Sensor and signature.

Settings — Choose which object to interact with.

• set vision object index — Specifies which detected object (by order) to reference in object-related Blocks.

Values — Access and use the captured data.

• vision object exists — Reports whether a detected object is present.

• vision object count — Reports the number of detected objects in the snapshot.

• vision object property — Reports details such as:

  • width & height — Size of the color signature.

  • centerX & centerY — Center position coordinates in the sensor’s view.

  • angle — Angle of the color signature.

Actions

take Vision Sensor snapshot

The take vision snapshot stack block will capture the current image from the Vision Sensor to be processed and analyzed for color signatures or color codes.

Color signatures and color codes must be configured first in the Vision Sensor Utility before they can be used with this block.

Note: A snapshot is required first before using any other Vision Sensor blocks.

The dataset stores objects ordered from largest to smallest by width, starting at index 0. Each object’s properties can be accessed using the vision object property block. An empty dataset is reported if no matching objects are detected.

  take a [Vision1 v] snapshot of [SELECT_A_SIG v]

Parameter	Description
device	Which Vision Sensor to use.
signature	Filters the dataset to only include data of the given signature. Available signatures are: NAME - A color signature or color code where NAME is the name configured in the Vision Sensor Utility

Settings

set Vision Sensor object item

The set Vision Sensor object item stack block sets which item in the dataset to use.

  set [Vision1 v] object item to (1)

Parameter	Description
device	Which Vision Sensor to use.
item	The number of the item in the dataset to use.

Values

Vision Sensor object exists

The vision object exists Boolean block reports whether a specified color signature or color code is detected in the dataset.

• True — The dataset includes a color signature or color code.

• False — The dataset does not include a color signature or color code.

  <[Vision1 v] object exists?>

Parameter	Description
device	Which Vision Sensor to use.

Vision Sensor object count

The vision object count reporter block reports the number of detected objects in the dataset as a whole number.

  ([Vision1 v] object count)

Parameter	Description
device	Which Vision Sensor to use.

Vision Sensor object property

There are five properties that are included with each object (shown below) stored after the take Vision Sensor snapshot block is used.

  ([Vision1 v] object [width v])

All property values describe the detected object’s position and size in the Vision Sensor’s view at the moment the take Vision Sensor snapshot block was used. These values are measured in pixels, based on the sensor’s 316 by 212 pixel resolution.

Parameter	Description
vision sensor	The Vision Sensor to use, configured in the Devices window.
property	Which property of the detected object to use: width height centerX centerY angle

width

The width property reports the width of the detected color signature in pixels as a whole number from 0 to 316.

The Vision object property stack block with its parameter set to width.

  [Vision1 v] object [width v]

height

The height property reports the height of the detected color signature in pixels as a whole number from 0 to 212.

The Vision object property stack block with its parameter set to height.

  [Vision1 v] object [height v]

centerX

The centerX property reports the x-coordinate of the center of the detected color signature in pixels as a whole number from 0 to 316.

The Vision object property stack block with its parameter set to centerX.

  [Vision1 v] object [centerX v]

centerY

The centerY property reports the y-coordinate of the center of the detected color signature in pixels as a whole number from 0 to 212.

The Vision object property stack block with its parameter set to centerY.

  [Vision1 v] object [centerY v]

angle

The angle property reports the orientation of the detected color code as a whole number in degrees from 0 to 180.

Note: The angle property can only be used with color codes.

The Vision object property stack block with its parameter set to angle.

  [Vision1 v] object [angle v]