Colony

/**

 * Copyright (c) 2007 Colony Project

 * 

 * Permission is hereby granted, free of charge, to any person

 * obtaining a copy of this software and associated documentation

 * files (the "Software"), to deal in the Software without

 * restriction, including without limitation the rights to use,

 * copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following

 * conditions:

 * 

 * The above copyright notice and this permission notice shall be

 * included in all copies or substantial portions of the Software.

 * 

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES

 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,

 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

 * OTHER DEALINGS IN THE SOFTWARE.

 **/

/**

 * @file encoders.h

 * @brief Contains functions for reading encoder values.

 *

 * Contains high and low level functions for reading encoders

 * including reading out total distance covered, and 

 * eventually velocity.

 *        

 * @author Colony Project, CMU Robotics Club

**/

/**

 * @defgroup encoders Encoders

 *

 * @brief Handles the encoders.

 *

 * Functions to read from the encoders, which tell

 * the distance the robot has travelled.

 *

 * @{

 **/

#ifndef __ENCODERS_H__

#define __ENCODERS_H__

#ifndef LEFT

        #define LEFT 0

#endif

#ifndef RIGHT

        #define RIGHT 1

#endif

/** @brief Magnet misaligned - likely distance from encoder problem. **/

#define ENCODER_MAGNET_FAILURE 1025

/** @brief Encoder misaligned - likely on XY plane. **/

#define ENCODER_MISALIGNED 1027

/** @brief Not enough time has passed - encoders not initialized in hardware. **/

#define ENCODER_DATA_NOT_READY 1026

//delay_ms argument after a full read is complete

#define ENCODER_DELAY 20

#define MIN_V (-100)

#define MAX_V 100

//Data invalid flags (hardware failure):

#define OCF _BV(4)

#define COF _BV(3)

//Data invalid alarm (May be invalid):

#define LIN _BV(2)

#define MagINCn _BV(1)

#define MagDECn _BV(0)

#define BUFFER_SIZE 23

/**

 * @brief Initialize encoders.

 *

 * Initializes encoder variables and the hardware interface.

**/

void encoders_init(void);

/**

 * @brief Read instantaneous encoder value.

 *

 * @param encoder this is the encoder that you want to read. Valid arguments

 *          are LEFT and RIGHT

 *

 * @return the value of the specified encoder

 **/

int encoder_read(char encoder);

/**

 * @brief Get total distance traveled.

 *

 * Gets the total distance covered by the specified encoder (in encoder clicks)

 *

 * @param encoder the encoder that you want to read, use LEFT or RIGHT

 *

 * @return The distance covered by the specified encoder.

 **/

int encoder_get_dx(char encoder);

/**

 * @brief Reset distance counter.

 *

 * Resets the distance accumulator for the specified

 *  encoder.

 *

 * @param encoder the encoder that you want to reset distance for

 **/

void encoder_rst_dx(char encoder);

/** 

* @brief Returns the number of encoder reads that have occurred.

* 

* Returns the number of encoder reads that have occurred.

* 

* @return The time count.

*/

int encoder_get_tc(void);

/** 

* @brief Resets the encoder read counter.

*/

void encoder_rst_tc(void);

/** 

* @brief Waits until n encoder reads have occurred.

*

* Waits until n encoder reads have occurred.

* Counter is reset on function's exit.

* 

* @param n 

*/

void encoder_wait( int nReadings );

/**@}**/ //end group

#endif