/* Reflow Oven Controller
*
* Copyright (C) 2020  Mario Hüttel <mario.huettel@gmx.net>
*
* This file is part of the Reflow Oven Controller Project.
*
* The reflow oven controller is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* The Reflow Oven Control Firmware 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 the reflow oven controller project.
* If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef __PID_CONTROLLER_H__
#define __PID_CONTROLLER_H__

struct pid_controller {
	float k_deriv;
	float k_int;
	float k_p;
	float k_int_t;
	float k_deriv_t;
	float k_inv_deriv_t;
	float output_sat_max;
	float output_sat_min;
	float integral_max;
	float sample_period;
	volatile float control_output;
	volatile float last_in;
	volatile float integral;
	volatile float derivate;
};

void pid_init(struct pid_controller *pid, float k_deriv, float k_int, float k_p,
	      float output_sat_min, float output_sat_max, float integral_max, float kd_tau, float sample_period);

void pid_zero(struct pid_controller *pid);

float pid_sample(struct pid_controller *pid, float deviation);

float pid_get_control_output(const struct pid_controller *pid);

int pid_copy(struct pid_controller *dest, const struct pid_controller *src);

#endif /* __PID_CONTROLLER_H__ */