robotCore.apriltags.ApriltagsCamera Class Reference

The ApriltagsCamera class handles communication with the Raspberry Pi Camera. More...

Inheritance diagram for robotCore.apriltags.ApriltagsCamera:

Classes
class	ApriltagsCameraRegion
	The ApriltagsCameraRegion specifies a single detected region. More...
class	ApriltagsCameraRegions
	The ApriltagsCameraRegions specifies list of detected regions. More...
class	ApriltagsCameraStats
	The ApriltagsCameraStats class collects the current camera performance statistics. More...
enum	ApriltagsCameraType

Public Member Functions
void	setCameraInfo (double xOffsetInches, double yOffsetInches, double angleOffsetInDegrees, ApriltagsCameraType type)
void	disableCameras (boolean disable)
boolean	isConnected ()
void	connect (String host, int port)
ApriltagsCameraStats	getStats ()
void	clearStats ()
ApriltagsCameraRegions	getRegions (int cameraNo)
boolean	isTagVisible ()
void	processRegions (SwerveDrivePoseEstimator poseEstimator)
void	setLogging (boolean log)
Public Member Functions inherited from robotCore.Network.NetworkReceiver
void	processData (String command)

Static Public Member Functions
static double	convertTime (long time)
static double	getTime ()
static double	normalizeAngle (double angle)

Detailed Description

The ApriltagsCamera class handles communication with the Raspberry Pi Camera.

Author

John Gaby

This class allows you to connect to the Data server of the Raspberry Pi and receive information about the image frames processed by the camera.

It also implements a time sync protocol to synchronize the clocks and performs keep-alive functions that detect a disconnect.

Member Function Documentation

clearStats()

void robotCore.apriltags.ApriltagsCamera.clearStats

(

)

Clears the camera performance stats

connect()

void robotCore.apriltags.ApriltagsCamera.connect	(	String	host,
		int	port )

Connects to the Raspberry Pi Data server

Parameters

host	- Specifies IP for the host
port	- Specifies the port (default is 5800)

convertTime()

static double robotCore.apriltags.ApriltagsCamera.convertTime ( long time )

static

This converts a specified time from that returned by System.currentTimeMillis() to same time base as returned by getTime()

Returns

Returns the converted time

Parameters

time	- Specifies the time in milliseconds.

disableCameras()

void robotCore.apriltags.ApriltagsCamera.disableCameras

(

boolean

disable

)

Disables the processing of the camera data

Parameters

disable

- If this value is set to true, the cameras will not update the robot's pose

getRegions()

ApriltagsCameraRegions robotCore.apriltags.ApriltagsCamera.getRegions

(

int

cameraNo

)

Returns

The latest set of camera regions.

Note that the data is received from the camera in a separate thread so calling this twice in a row can generate a different result. Once you retrieve and instance of ApriltagsCameraRegions however, you can be assured that it will NOT be modified when a new frame is received.

getStats()

ApriltagsCameraStats robotCore.apriltags.ApriltagsCamera.getStats

(

)

Returns the current camera performance stats

getTime()

static double robotCore.apriltags.ApriltagsCamera.getTime ( )

static

Returns

The current time which has been synchronized with the camera.

isConnected()

boolean robotCore.apriltags.ApriltagsCamera.isConnected

(

)

Returns

true if connected to the camera

isTagVisible()

boolean robotCore.apriltags.ApriltagsCamera.isTagVisible

(

)

Returns

true if at least one apriltag is visible by either camera

normalizeAngle()

static double robotCore.apriltags.ApriltagsCamera.normalizeAngle ( double angle )

static

This converts the specified angle so that is is between -180 and +180 degrees

Returns

Returns the same angle but guarantees that it is between -180 and +180 degrees.

Parameters

angle

- specifies the angle in degrees

processRegions()

void robotCore.apriltags.ApriltagsCamera.processRegions

(

SwerveDrivePoseEstimator

poseEstimator

)

This function processes the apriltags for the current camera frame and updates the robot's position. This should be called from the main loop.

Parameters

poseEstimator

- Specifies the poseEstimator that is being used to keep track of the robot's position.

setCameraInfo()

void robotCore.apriltags.ApriltagsCamera.setCameraInfo	(	double	xOffsetInches,
		double	yOffsetInches,
		double	angleOffsetInDegrees,
		ApriltagsCameraType	type )

Sets the camera position and type for each of the cameras attached to the PI (max of 2 cameras)

Parameters

xOffsetInches	- Specifies the x offset of the camera from the center of the robot in inches
yOffsetInches	- Specifies the y offset of the camera from the center of the robot in inches
angleOffsetInDegrees	- Specifies the orientation of the camera in

setLogging()

void robotCore.apriltags.ApriltagsCamera.setLogging

(

boolean

log

)

This enables/disables extensive logging to file

Parameters

log	- If true, log the camera info to a file.

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The documentation for this class was generated from the following file:

• D:/SDASVN/2024/RaspberryPi/VSCode/Source/robotCore/apriltags/ApriltagsCamera.java