NXTCam Vision System [Mindsensors]

Data Structures
struct	blob
Files
file	mindsensors-nxtcam.h
	Mindsensors NXTCam driver.
Defines
#define	MAX_BLOBS   8
#define	NXTCAM_I2C_ADDR   0x02
#define	NXTCAM_CMD_REG   0x41
#define	NXTCAM_COUNT_REG   0x42
#define	NXTCAM_DATA_REG   0x43
#define	SIDE_CENTER(X1, X2)   ((X1 + X2) / 2)
Typedefs
typedef blob	blob_array [MAX_BLOBS]
Functions
bool	NXTCAMinit (tSensors link, ubyte address=NXTCAM_I2C_ADDR)
bool	NXTCAMinitTL (tSensors link, ubyte address=NXTCAM_I2C_ADDR)
int	NXTCAMgetBlobs (tSensors link, blob_array &blobs, bool mergeBlobs, ubyte address=NXTCAM_I2C_ADDR)
int	NXTCAMgetBlobs (tSensors link, blob_array &blobs, ubyte address=NXTCAM_I2C_ADDR)
bool	_camera_cmd (tSensors link, byte cmd, ubyte address)
int	_mergeBlobs (int blob1, int blob2, int nblobs, blob_array &blobs)
int	_merge (int nblobs, blob_array &blobs)
void	_sortBlobs (int nblobs, blob_array &blobs)
void	NXTCAMgetAverageCenter (blob_array &blobs, int nblobs, int colourindex, int &x, int &y)
void	NXTCAMgetCenter (blob_array &blobs, int index, int &x, int &y)
Variables
tByteArray	NXTCAM_I2CRequest
tByteArray	NXTCAM_I2CReply
bool	still_merging = false

---

Detailed Description

NXTCam Vision System

---

Define Documentation

#define MAX_BLOBS   8

Maximum number of blobs returned by the NXTCam

Definition at line 48 of file mindsensors-nxtcam.h.

#define NXTCAM_CMD_REG   0x41

Register used for issuing commands

Definition at line 50 of file mindsensors-nxtcam.h.

#define NXTCAM_COUNT_REG   0x42

Register used to hold number of blobs detected

Definition at line 51 of file mindsensors-nxtcam.h.

#define NXTCAM_DATA_REG   0x43

Register containing data pertaining to blobs

Definition at line 52 of file mindsensors-nxtcam.h.

#define NXTCAM_I2C_ADDR   0x02

I2C address used by the NXTCam

Definition at line 49 of file mindsensors-nxtcam.h.

#define SIDE_CENTER	(		X1,
			X2
	)		((X1 + X2) / 2)

Returns the center of a side

Definition at line 54 of file mindsensors-nxtcam.h.

---

Typedef Documentation

typedef blob blob_array[MAX_BLOBS]

Array of blob as a typedef, this is a work around for RobotC's inability to pass an array to a function

Examples:

mindsensors-nxtcam-test1.c.

Definition at line 67 of file mindsensors-nxtcam.h.

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Function Documentation

bool _camera_cmd	(	tSensors	link,
		byte	cmd,
		ubyte	address
	)

This function sends a command to the camera over I2C.

Note: this is an internal function and should not be called directly.

Parameters:

link	the sensor port number
cmd	the command to be sent
address	the I2C address to use, optional, defaults to 0x02

Returns:

true if no error occured, false if it did

Definition at line 98 of file mindsensors-nxtcam.h.

int _merge	(	int	nblobs,
		blob_array &	blobs
	)

Go through the blobs and calls _mergeBlobs.

Note: this is an internal function and should not be called directly.

Parameters:

nblobs	the number of blobs
blobs	the array of blobs

Returns:

the number of blobs detected

Definition at line 232 of file mindsensors-nxtcam.h.

int _mergeBlobs	(	int	blob1,
		int	blob2,
		int	nblobs,
		blob_array &	blobs
	)

Check if two blobs can be merged into one. blob1 will be replaced with the new merged blob and blob2 will be destroyed.

Note: this is an internal function and should not be called directly.

Parameters:

blob1	the index number of the first blob
blob2	the index number of the second blob
nblobs	the number of blobs
blobs	the array of blobs

Returns:

the number of blobs detected

Definition at line 256 of file mindsensors-nxtcam.h.

void _sortBlobs	(	int	nblobs,
		blob_array &	blobs
	)

This function sorts the blobs in the array using insertion sort.

Note: this is an internal function and should not be called directly.

Parameters:

nblobs	the number of blobs
blobs	the array of blobs

Definition at line 326 of file mindsensors-nxtcam.h.

void NXTCAMgetAverageCenter	(	blob_array &	blobs,
		int	nblobs,
		int	colourindex,
		int &	x,
		int &	y
	)

Calculate the average center of all the blobs of a specific colour.

Note: this is an experimental function and may not function properly yet.

Parameters:

blobs	the array of blobs
nblobs	the number of blobs
colourindex	the colour of the blobs of which the average center is to be calculated
x	x-coordinate of the center
y	y-coordinate of the center

Definition at line 358 of file mindsensors-nxtcam.h.

int NXTCAMgetBlobs	(	tSensors	link,
		blob_array &	blobs,
		ubyte	address
	)

This function fetches the blob data from the camera.

Parameters:

link	the sensor port number
blobs	the array of blobs
address	the I2C address to use, optional, defaults to 0x02

Returns:

the number of blobs detected, -1 if an error occurred

Definition at line 183 of file mindsensors-nxtcam.h.

int NXTCAMgetBlobs	(	tSensors	link,
		blob_array &	blobs,
		bool	mergeBlobs,
		ubyte	address
	)

This function fetches the blob data from the camera and merges the colliding ones.

Parameters:

link	the sensor port number
blobs	the array of blobs
mergeBlobs	whether or not to merge the colliding blobs
address	the I2C address to use, optional, defaults to 0x02

Returns:

the number of blobs detected, -1 if an error occurred

Examples:

mindsensors-nxtcam-test1.c.

Definition at line 169 of file mindsensors-nxtcam.h.

void NXTCAMgetCenter	(	blob_array &	blobs,
		int	index,
		int &	x,
		int &	y
	)

Calculate the center of a specified blob.

Note: this is an experimental function and may not function properly yet.

Parameters:

blobs	the array of blobs
index	the blob that you want to calculate the center of
x	x-coordinate of the center
y	y-coordinate of the center

Definition at line 384 of file mindsensors-nxtcam.h.

bool NXTCAMinit	(	tSensors	link,
		ubyte	address
	)

This function initialises camera ready to find blobs and sort them according to size.

Parameters:

link	the sensor port number
address	the I2C address to use, optional, defaults to 0x02

Returns:

true if no error occured, false if it did

Examples:

mindsensors-nxtcam-test1.c.

Definition at line 113 of file mindsensors-nxtcam.h.

bool NXTCAMinitTL	(	tSensors	link,
		ubyte	address
	)

This function initialises camera ready to track lines.

Parameters:

link	the sensor port number
address	the I2C address to use, optional, defaults to 0x02

Returns:

true if no error occured, false if it did

Definition at line 140 of file mindsensors-nxtcam.h.

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Variable Documentation

tByteArray NXTCAM_I2CReply

Array to hold I2C reply data

Definition at line 70 of file mindsensors-nxtcam.h.

tByteArray NXTCAM_I2CRequest

Array to hold I2C command data

Definition at line 69 of file mindsensors-nxtcam.h.

bool still_merging = false

boolean to signal if there are still blobs that might qualify for merging

Definition at line 87 of file mindsensors-nxtcam.h.