/**
* @file pi.h
* @note Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
*
* This program is 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 program 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 this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef HAVE_PI_H
#define HAVE_PI_H
#include "servo.h"
/**
* When set to a non-zero value, this variable determines the
* proportional constant for the PI controller.
*/
extern double configured_pi_kp;
/**
* When set to a non-zero value, this variable determines the
* integral constant for the PI controller.
*/
extern double configured_pi_ki;
/**
* When set to a non-zero value, this variable determines the scale in the
* formula used to set the proportional constant of the PI controller from the
* sync interval.
* kp = min(kp_scale * sync^kp_exponent, kp_norm_max / sync)
*/
extern double configured_pi_kp_scale;
/**
* This variable determines the exponent in the formula used to set the
* proportional constant of the PI controller from the sync interval.
* kp = min(kp_scale * sync^kp_exponent, kp_norm_max / sync)
*/
extern double configured_pi_kp_exponent;
/**
* This variable determines the normalized maximum in the formula used to set
* the proportional constant of the PI controller from the sync interval.
* kp = min(kp_scale * sync^kp_exponent, kp_norm_max / sync)
*/
extern double configured_pi_kp_norm_max;
/**
* When set to a non-zero value, this variable determines the scale in the
* formula used to set the integral constant of the PI controller from the
* sync interval.
* ki = min(ki_scale * sync^ki_exponent, ki_norm_max / sync)
*/
extern double configured_pi_ki_scale;
/**
* This variable determines the exponent in the formula used to set the
* integral constant of the PI controller from the sync interval.
* ki = min(ki_scale * sync^ki_exponent, ki_norm_max / sync)
*/
extern double configured_pi_ki_exponent;
/**
* This variable determines the normalized maximum in the formula used to set
* the integral constant of the PI controller from the sync interval.
* ki = min(ki_scale * sync^ki_exponent, ki_norm_max / sync)
*/
extern double configured_pi_ki_norm_max;
/**
* When set to a non-zero value, this variable controls the maximum allowed
* offset before a clock jump occurs instead of the default clock-slewing
* mechanism.
*
* Note that this variable is measured in seconds, and allows fractional values.
*/
extern double configured_pi_offset;
/**
* When set to zero, the clock is not stepped on start. When set to a non-zero
* value, the value bahaves as a threshold and the clock is stepped on start if
* the offset is bigger than the threshold.
*
* Note that this variable is measured in seconds, and allows fractional values.
*/
extern double configured_pi_f_offset;
/**
* When set to a non-zero value, this variable sets an additional limit for
* the frequency adjustment of the clock. It's in ppb.
*/
extern int configured_pi_max_freq;
struct servo *pi_servo_create(int fadj, int max_ppb, int sw_ts);
#endif
