Revision 1953

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trunk/code/projects/linefollowing/lineFollow.h
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#include <dragonfly_lib.h>
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#ifndef _LINEFOLLOW_H_
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#define _LINEFOLLOW_H_
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#define LWHITE			0
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#define LGREY			1
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#define LBLACK	 		2
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#define CENTER			3
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#define LINELOST		-1
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#define NOBARCODE 		-2
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#define INTERSECTION 	-25
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#define NOLINE			-50
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#define FULL_LINE 		-51
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//! Number of consecutive barcode color readings for a significant reading.
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#define MAX_DURATION    20
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//! Number of consecutive white barcode readings before a barcode reset.
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#define TIMEOUT_DURATION    1000
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//! Anything lower than this value is white
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#define GREY_THRESHOLD 100
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//! Anything higher than this value is black
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#define BLACK_THRESHOLD 400
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#define LEFT_SENSOR     1
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#define RIGHT_SENSOR    0
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/**
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 * @brief Initializes line following.
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 * 
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 * Must be called before line following will work.
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 * Turns the analog loop off.
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 */
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void lineFollow_init(void);
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/**	lineFollow
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 *	Must call lineFollow_init first
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 *	Must be called inside a loop
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 */
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int lineFollow(int speed);
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/**	turnLeft turnRight mergeLeft mergeRight
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 *	Must be called inside a loop
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 *	returns 0 when complete
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 */
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int turnLeft(void);
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int turnRight(void);
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int mergeLeft(void);
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int mergeRight(void);
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/**
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 * @brief Updates the values stored in the array to white or black based on
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 * current sensor readings.
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 *
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 * @param values The array of five integers to be updated. 
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 */
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void updateLine(int* values); 
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/**
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 * @brief Returns an index of the middle of the line based on line readings.
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 *
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 * Two special return values are possible:
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 *   NOLINE if none of the sensors holds a black value, and
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 *   FULL_LINE if all of the sensors see black.
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 *
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 * Otherwise, returns a value from -4 (farthest left) to 4 (farthest right), with
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 * 0 the line being centered in the middle.
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 *
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 * @param colors The array of 5 readings from the line sensor.  Must be either
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 *    LWHITE or LBLACK.
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 * @return Either a special value or an index from -4 to 4.
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 *
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 */
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int lineLocate(int* colors);
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/**	updatebarCode
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 *	Reads in and processes
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 *	bar code data
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 */
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void updateBarCode(void);
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/**
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 * @brief Gets the completed value read by the barcode reader, or NOBARCODE.
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 *
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 * Returns a bar code if available (if at the end of a barcode) and resets the
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 * barcodePosition to 0. Otherwise, return NOBARCODE.  *
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 * @return The value of the barcode if a complete barcode, else NOBARCODE.
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 */
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int getBarCode(void);
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//! A simple function to return the minimum of two integers.
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int min(int x, int y);
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//! A simple function to return the maximum of two integers.
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int max(int x, int y);
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/** @todo Alex: I hate these functions, but I'm keeping them so code will still work. But we should delete them sometime. */
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/**	motorLeft
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 *	Commands the left motor
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 *	Cannot be used to stop
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 *	0-126 are backward
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 *	127-255 are forward
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 */
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void motorLeft(int speed);
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/**	motorRight
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 *	Commands the right motor
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 *	Cannot be used to stop
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 *	0-126 are backward
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 *	127-255 are forward
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 */
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void motorRight(int speed);
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/**	lost
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 *	Internal counter to detect if the line was lost
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 */
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int lost;
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int onLine(void);
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#endif

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