pid/ec/pid.hpp

#pragma once

#include <cstdint>

namespace ec
{

typedef struct
{
    float min;
    float max;
} limits_t;

/* Note: If you update these structs you need to update the copy code in
 * pid/util.cpp.
 */
typedef struct
{
    bool initialized; // has pid been initialized

    float ts;          // sample time in seconds
    float integral;    // intergal of error
    float last_output; // value of last output

    float p_c;     // coeff for P
    float i_c;     // coeff for I
    float ff_off;  // offset coeff for feed-forward term
    float ff_gain; // gain for feed-forward term

    limits_t i_lim;   // clamp of integral
    limits_t out_lim; // clamp of output
    float slew_neg;
    float slew_pos;
} pid_info_t;

float pid(pid_info_t* pidinfoptr, float input, float setpoint);

/* Condensed version for use by the configuration. */
struct pidinfo
{
    float ts;             // sample time in seconds
    float p_c;            // coeff for P
    float i_c;            // coeff for I
    float ff_off;         // offset coeff for feed-forward term
    float ff_gain;        // gain for feed-forward term
    ec::limits_t i_lim;   // clamp of integral
    ec::limits_t out_lim; // clamp of output
    float slew_neg;
    float slew_pos;
};

} // namespace ec