--- a/brewco/pid.c Thu Feb 25 22:42:54 2016 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,267 +0,0 @@
-/*****************************************************************************
- * Copyright (C) 2015
- *
- * Michiel Broek <mbroek at mbse dot eu>
- *
- * This file is part of the mbsePi-apps
- *
- * This 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, or (at your option) any
- * later version.
- *
- * mbsePi-apps 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 ThermFerm; see the file COPYING. If not, write to the Free
- * Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
- *
- * Based on the Arduino PID Library 1.1.1 by Brett Beauregard <br3ttb@gmail.com>
- * This Library is licensed under a GPLv3 License
- *****************************************************************************/
-
-#include "brewco.h"
-#include "pid.h"
-#include "util.h"
-
-
-/*
- * The parameters specified here are those for for which we can't set up
- * reliable defaults, so we need to have the user set them.
- */
-void PID_init(pid_var *pid, double *Input, double *Output, double *Setpoint, double Kp, double Ki, double Kd, int ControllerDirection)
-{
- pid->myOutput = Output;
- pid->myInput = Input;
- pid->mySetpoint = Setpoint;
- pid->inAuto = FALSE;
- PID_setOutputLimits(pid, 0, 255);
- pid->SampleTime = 100;
- PID_setDirection(pid, ControllerDirection);
- PID_setTunings(pid, Kp, Ki, Kd);
- pid->lastTime = millis() - pid->SampleTime;
-}
-
-
-
-/*
- * Allows the controller Mode to be set to manual (0) or Automatic (non-zero)
- * when the transition from manual to auto occurs, the controller is
- * automatically initialized
- */
-void PID_setMode(pid_var *pid, int Mode)
-{
- int newAuto = (Mode == P_AUTOMATIC);
-
- if (newAuto != pid->inAuto) {
- /*
- * we just went from manual to auto
- */
- pid->ITerm = *pid->myOutput;
- pid->lastInput = *pid->myInput;
- if (pid->ITerm > pid->outMax)
- pid->ITerm = pid->outMax;
- else if (pid->ITerm < pid->outMin)
- pid->ITerm = pid->outMin;
- /*
- * If turned to manual, turn output off.
- */
- if (Mode == P_MANUAL)
- *pid->myOutput = pid->outMin;
- }
- pid->inAuto = newAuto;
-}
-
-
-
-/*
- * This function will be used far more often than SetInputLimits. while
- * the input to the controller will generally be in the 0-1023 range (which is
- * the default already,) the output will be a little different. maybe they'll
- * be doing a time window and will need 0-8000 or something. or maybe they'll
- * want to clamp it from 0-125. who knows. at any rate, that can all be done
- * here.
- */
-void PID_setOutputLimits(pid_var *pid, double Min, double Max)
-{
- if (Min >= Max)
- return;
-
- pid->outMin = Min;
- pid->outMax = Max;
-
- if (pid->inAuto == P_AUTOMATIC) {
- if (*pid->myOutput > pid->outMax)
- *pid->myOutput = pid->outMax;
- else if (*pid->myOutput < pid->outMin)
- *pid->myOutput = pid->outMin;
-
- if (pid->ITerm > pid->outMax)
- pid->ITerm = pid->outMax;
- else if (pid->ITerm < pid->outMin)
- pid->ITerm = pid->outMin;
- }
-}
-
-
-
-/*
- * This function allows the controller's dynamic performance to be adjusted.
- * it's called automatically from the constructor, but tunings can also
- * be adjusted on the fly during normal operation.
- */
-void PID_setTunings(pid_var *pid, double Kp, double Ki, double Kd)
-{
- if (Kp < 0 || Ki < 0 || Kd < 0)
- return;
- pid->dispKp = Kp;
- pid->dispKi = Ki;
- pid->dispKd = Kd;
-
- double SampleTimeInSec = ((double)pid->SampleTime) / 1000;
- pid->Kp = Kp;
- pid->Ki = Ki * SampleTimeInSec;
- pid->Kd = Kd / SampleTimeInSec;
-
- if (pid->Direction == P_REVERSE) {
- pid->Kp = (0 - pid->Kp);
- pid->Ki = (0 - pid->Ki);
- pid->Kd = (0 - pid->Kd);
- }
-}
-
-
-
-/*
- * The PID will either be connected to a DIRECT acting process (+Output leads
- * to +Input) or a REVERSE acting process(+Output leads to -Input.) we need to
- * know which one, because otherwise we may increase the output when we should
- * be decreasing. This is called from PID_init().
- */
-void PID_setDirection(pid_var *pid, int Direction)
-{
- if (pid->inAuto && Direction != pid->Direction) {
- pid->Kp = (0 - pid->Kp);
- pid->Ki = (0 - pid->Ki);
- pid->Kd = (0 - pid->Kd);
- }
- pid->Direction = Direction;
-}
-
-
-
-/*
- * sets the period, in Milliseconds, at which the calculation is performed.
- */
-void PID_setSampleTime(pid_var *pid, int NewSampleTime)
-{
- if (NewSampleTime > 0) {
- double ratio = (double)NewSampleTime / (double)pid->SampleTime;
-
- pid->Ki *= ratio;
- pid->Kd /= ratio;
- pid->SampleTime = NewSampleTime;
- }
-}
-
-
-
-/*
- * Just because you set the Kp=-1 doesn't mean it actually happened. these
- * functions query the internal state of the PID. they're here for display
- * purposes. this are the functions the PID Front-end uses for example
- */
-double PID_getKp(pid_var *pid)
-{
- return pid->dispKp;
-}
-
-
-
-double PID_getKi(pid_var *pid)
-{
- return pid->dispKi;
-}
-
-
-
-double PID_getKd(pid_var *pid)
-{
- return pid->dispKd;
-}
-
-
-
-int PID_getMode(pid_var *pid)
-{
- return pid->inAuto ? P_AUTOMATIC : P_MANUAL;
-}
-
-
-
-int PID_getDirection(pid_var *pid)
-{
- return pid->Direction;
-}
-
-
-
-int PID_getSampleTime(pid_var *pid)
-{
- return pid->SampleTime;
-}
-
-
-
-/*
- * This, as they say, is where the magic happens. this function should be called
- * every time "void loop()" executes. the function will decide for itself whether a new
- * pid Output needs to be computed. returns true when the output is computed,
- * false when nothing has been done.
- */
-int PID_compute(pid_var *pid)
-{
- if (! pid->inAuto)
- return FALSE;
-
- long now = millis();
- long timeChange = (now - pid->lastTime);
-
- if (timeChange >= pid->SampleTime) {
- /*
- * Compute all the working error variables
- */
- double input = *pid->myInput;
- double error = *pid->mySetpoint - input;
- pid->ITerm += (pid->Ki * error);
- if (pid->ITerm > pid->outMax)
- pid->ITerm = pid->outMax;
- else if (pid->ITerm < pid->outMin)
- pid->ITerm = pid->outMin;
- double dInput = input - pid->lastInput;
-
- /*
- * Compute PID output
- */
- double output = pid->Kp * error + pid->ITerm - pid->Kd * dInput;
- if (output > pid->outMax)
- output = pid->outMax;
- else if (output < pid->outMin)
- output = pid->outMin;
- *pid->myOutput = output;
-
- /*
- * Remember some variables for the next time
- */
- pid->lastInput = input;
- pid->lastTime = now;
- return TRUE;
- }
-
- return FALSE;
-}
-
-