/***************************************************************************/
/* kalman.h header file for kalman.c                                       */
/* 1-D Kalman filter Algorithm, using an inclinometer and gyro             */
/* Author: Rich Chi Ooi                                                    */
/* Version: 1.0                                                            */
/* Date:30.05.2003                                                         */ 
/* Adapted from Trammel Hudson(hudson@rotomotion.com)                      */     
/* -------------------------------                                         */
/* Compilation  procedure:                                                 */
/*       Linux                                                             */
/*      gcc68 -c  XXXXXX.c (to create object file)                         */
/*      gcc68 -o  XXXXXX.hex XXXXXX.o ppwa.o                               */
/***************************************************************************/
/* In this version:                                                        */
/***************************************************************************/
/* This is a free software; you can redistribute it and/or modify          */
/* it under the terms of the GNU General Public License as published       */
/* by the Free Software Foundation; either version 2 of the License,       */ 
/* or (at your option) any later version.                                  */
/*                                                                         */
/* this code is distributed in the hope that it will be useful,            */
/* but WITHOUT ANY WARRANTY; without even the implied warranty of          */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           */
/* GNU General Public License for more details.                            */
/*                                                                         */ 
/* You should have received a copy of the GNU General Public License       */
/* along with Autopilot; if not, write to the Free Software                */
/* Foundation, Inc., 59 Temple Place, Suite 330, Boston,                   */
/* MA  02111-1307  USA                                                     */
/***************************************************************************/

#ifndef kalman_h
#define kalman_h

/*
 * Our two states, the angle and the gyro bias.As a byproduct of computing
 * the angle, we also have an unbiased angular rate available.These are
 * read-only to the user of the module.
 */
extern float angle;
extern float q_bias;
extern float rate;


/*
 * stateUpdate is called every dt with a biased gyro measurement
 * by the user of the module.  It updates the current angle and
 * rate estimate.
 */
void stateUpdate(const float q_m);

/*
 * kalmanUpdate is called by a user of the module when a new
 * inclinoometer measurement is available. 
 */
void kalmanUpdate(const float incAngle);

#endif