Update

New examples for MAX6675 and PTC heater

README.md

@@ -12,7 +12,7 @@ Accurate determination of the inflection point was given high priority for this
 
 #### S-shaped Step Response
 
-![Reaction Curve](https://user-images.githubusercontent.com/63488701/151797252-63b6c4d1-2781-459a-81f8-22f931a4a96b.png)
+![Reaction Curve](https://user-images.githubusercontent.com/63488701/151890696-d574d77b-b849-4079-81e2-71e4ee416fa3.png)
 
 #### Configuration
 

examples/MAX31856_PTC_SSR/Get_All_Tunings/Get_All_Tunings.ino

@@ -1,6 +1,7 @@
-/***************************************************************
+/*****************************************************************************
   sTune Get All Tunings Example (MAX31856, PTC Heater and SSR)
- ***************************************************************/
+  Reference: https://github.com/Dlloydev/sTune/wiki/Examples_MAX31856_PTC_SSR
+  ****************************************************************************/
 #include <Adafruit_MAX31856.h>
 #include <sTune.h>
 

examples/MAX31856_PTC_SSR/sTune_PID_v1/sTune_PID_v1.ino

@@ -1,10 +1,11 @@
-/***************************************************************
+/****************************************************************************
   sTune PID_v1 Example
   This sketch does on-the-fly tunning and PID SSR control of a
   PTC heater. Tunning parameters are quickly determined and
   applied during the temperature ramp-up to setpoint. Open
   the serial plotter to view the graphical results.
- ***************************************************************/
+  Reference: https://github.com/Dlloydev/sTune/wiki/Examples_MAX31856_PTC_SSR
+  ****************************************************************************/
 
 #include <Adafruit_MAX31856.h>
 #include <sTune.h>
@@ -32,7 +33,7 @@ float Input, Output, Setpoint = 50, Kp, Ki, Kd; // sTune
 
 Adafruit_MAX31856 maxthermo = Adafruit_MAX31856(10); //SPI
 sTune tuner = sTune(&Input, &Output, tuner.ZN_PID, tuner.directIP, tuner.printOFF);
-PID myPID(&input, &output, &setpoint, 0, 0, 0, P_ON_M, DIRECT);
+PID myPID(&input, &output, &setpoint, kp, ki, kd, P_ON_M, DIRECT);
 
 void setup() {
   pinMode(drdyPin, INPUT);
@@ -64,15 +65,18 @@ void loop() {
       myPID.SetOutputLimits(0, outputSpan * 0.1);
       myPID.SetSampleTime(outputSpan * 0.4);
       debounce = 0; // switch to SSR optimum cycle mode
-      output = outputStep, kp = Kp, ki = Ki, kd = Kd;
+      setpoint = Setpoint, output = outputStep, kp = Kp, ki = Ki, kd = Kd;
       myPID.SetMode(AUTOMATIC); // the PID is turned on
+      output = outputStep;
+      Output = output;
       myPID.SetTunings(kp, ki, kd); // update PID with the new tunings
       break;
 
     case tuner.runPid: // active once per sample after tunings
-      if (!digitalRead(drdyPin)) input = maxthermo.readThermocoupleTemperature();
+      if (!digitalRead(drdyPin)) Input = maxthermo.readThermocoupleTemperature();
+      input = Input;
       myPID.Compute();
-      Input = input, Output = output;
+      Output = output;
       tuner.plotter(Input, optimumOutput, Setpoint, 1, 3);
       break;
   }

examples/MAX31856_PTC_SSR/sTune_QuickPID/sTune_QuickPID.ino

@@ -1,10 +1,11 @@
-/**************************************************************
+/***************************************************************************
   sTune QuickPID Example
   This sketch does on-the-fly tunning and PID SSR control of a
   PTC heater. Tunning parameters are quickly determined and
   applied during the temperature ramp-up to setpoint. Open
   the serial plotter to view the graphical results.
-  *************************************************************/
+  Reference: https://github.com/Dlloydev/sTune/wiki/Examples_MAX31856_PTC_SSR
+  ***************************************************************************/
 
 #include <Adafruit_MAX31856.h>
 #include <sTune.h>

examples/MAX6675_PTC_SSR/Get_All_Tunings/Get_All_Tunings.ino

@@ -0,0 +1,74 @@
+/***************************************************************************
+  sTune Get All Tunings Example (MAX6675, PTC Heater and SSR)
+  Reference: https://github.com/Dlloydev/sTune/wiki/Examples_MAX6675_PTC_SSR
+ ***************************************************************************/
+
+#include <max6675.h>
+#include <sTune.h>
+
+// pins
+const uint8_t inputPin = 0;
+const uint8_t relayPin = 3;
+const uint8_t drdyPin = 5;
+const uint8_t SO = 12;
+const uint8_t CS = 10;
+const uint8_t sck = 13;
+
+// user settings
+uint32_t settleTimeSec = 10;
+uint32_t testTimeSec = 500;
+const uint16_t samples = 500;
+const float inputSpan = 220;
+const float outputSpan = 1000;
+float outputStart = 0;
+float outputStep = 50;
+float tempLimit = 100;
+
+// variables
+float Input, Output;
+
+MAX6675 module(sck, CS, SO); //SPI
+sTune tuner = sTune(&Input, &Output, tuner.ZN_PID, tuner.directIP, tuner.printALL);
+
+void setup() {
+  pinMode(drdyPin, INPUT);
+  pinMode(relayPin, OUTPUT);
+  Serial.begin(115200);
+  while (!Serial) delay(10);
+  delay(3000);
+  Output = 0;
+  tuner.Configure(inputSpan, outputSpan, outputStart, outputStep, testTimeSec, settleTimeSec, samples);
+  tuner.SetEmergencyStop(tempLimit);
+}
+
+void loop() {
+  tuner.softPwm(relayPin, Input, Output, 0, outputSpan, 1);
+
+  switch (tuner.Run()) {
+    case tuner.sample: // active once per sample during test
+      Input = module.readCelsius();
+      break;
+
+    case tuner.tunings: // active just once when sTune is done
+      Output = 0;
+      tuner.SetTuningMethod(tuner.TuningMethod::DampedOsc_PID);
+      tuner.printTunings();
+      tuner.SetTuningMethod(tuner.TuningMethod::NoOvershoot_PID);
+      tuner.printTunings();
+      tuner.SetTuningMethod(tuner.TuningMethod::CohenCoon_PID);
+      tuner.printTunings();
+      tuner.SetTuningMethod(tuner.TuningMethod::Mixed_PID);
+      tuner.printTunings();
+      tuner.SetTuningMethod(tuner.TuningMethod::ZN_PI);
+      tuner.printTunings();
+      tuner.SetTuningMethod(tuner.TuningMethod::DampedOsc_PI);
+      tuner.printTunings();
+      tuner.SetTuningMethod(tuner.TuningMethod::NoOvershoot_PI);
+      tuner.printTunings();
+      tuner.SetTuningMethod(tuner.TuningMethod::CohenCoon_PI);
+      tuner.printTunings();
+      tuner.SetTuningMethod(tuner.TuningMethod::Mixed_PI);
+      tuner.printTunings();
+      break;
+  }
+}

examples/MAX6675_PTC_SSR/sTune_PID_v1/sTune_PID_v1.ino

@@ -0,0 +1,80 @@
+/***************************************************************************
+  sTune PID_v1 Example
+  This sketch does on-the-fly tunning and PID SSR control of a
+  PTC heater. Tunning parameters are quickly determined and
+  applied during the temperature ramp-up to setpoint. Open
+  Reference: https://github.com/Dlloydev/sTune/wiki/Examples_MAX6675_PTC_SSR
+  ***************************************************************************/
+
+#include <max6675.h>
+#include <sTune.h>
+#include <PID_v1.h>
+
+// pins
+const uint8_t inputPin = 0;
+const uint8_t relayPin = 3;
+const uint8_t drdyPin = 5;
+const uint8_t SO = 12;
+const uint8_t CS = 10;
+const uint8_t sck = 13;
+
+// user settings
+uint32_t settleTimeSec = 10;
+uint32_t testTimeSec = 500;
+const uint16_t samples = 500;
+const float inputSpan = 200;
+const float outputSpan = 1000;
+float outputStart = 0;
+float outputStep = 30;
+float tempLimit = 75;
+uint8_t debounce = 1;
+
+// variables
+double input, output, setpoint = 50, kp, ki, kd; // PID_v1
+float Input, Output, Setpoint = 50, Kp, Ki, Kd; // sTune
+
+MAX6675 module(sck, CS, SO); //SPI
+sTune tuner = sTune(&Input, &Output, tuner.ZN_PID, tuner.directIP, tuner.printOFF);
+PID myPID(&input, &output, &setpoint, kp, ki, kd, P_ON_M, DIRECT);
+
+void setup() {
+  pinMode(drdyPin, INPUT);
+  pinMode(relayPin, OUTPUT);
+  Serial.begin(115200);
+  while (!Serial) delay(10);
+  delay(3000);
+  Output = 0;
+  tuner.Configure(inputSpan, outputSpan, outputStart, outputStep, testTimeSec, settleTimeSec, samples);
+  tuner.SetEmergencyStop(tempLimit);
+}
+
+void loop() {
+  float optimumOutput = tuner.softPwm(relayPin, Input, Output, Setpoint, outputSpan, debounce);
+
+  switch (tuner.Run()) {
+    case tuner.sample: // active once per sample during test
+      Input = module.readCelsius();
+      tuner.plotter(Input, Output, Setpoint, 1, 3);
+      break;
+
+    case tuner.tunings: // active just once when sTune is done
+      tuner.GetAutoTunings(&Kp, &Ki, &Kd); // sketch variables updated by sTune
+      myPID.SetOutputLimits(0, outputSpan * 0.1);
+      myPID.SetSampleTime(outputSpan * 0.2);
+      debounce = 0; // switch to SSR optimum cycle mode
+      setpoint = Setpoint, output = outputStep, kp = Kp, ki = Ki, kd = Kd;
+      myPID.SetMode(AUTOMATIC); // the PID is turned on
+      output = outputStep;
+      Output = output;
+      myPID.SetTunings(kp, ki, kd); // update PID with the new tunings
+      break;
+
+    case tuner.runPid: // active once per sample after tunings
+      Input = module.readCelsius();
+      input = Input;
+      myPID.Compute();
+      Output = output;
+      tuner.plotter(Input, optimumOutput, Setpoint, 1, 3);
+      break;
+  }
+}

examples/MAX6675_PTC_SSR/sTune_QuickPID/sTune_QuickPID.ino

@@ -0,0 +1,77 @@
+/***************************************************************************
+  sTune QuickPID Example
+  This sketch does on-the-fly tunning and PID SSR control of a
+  PTC heater. Tunning parameters are quickly determined and
+  applied during the temperature ramp-up to setpoint. Open
+  the serial plotter to view the graphical results.
+  Reference: https://github.com/Dlloydev/sTune/wiki/Examples_MAX6675_PTC_SSR
+  ***************************************************************************/
+
+#include <max6675.h>
+#include <sTune.h>
+#include <QuickPID.h>
+
+// pins
+const uint8_t inputPin = 0;
+const uint8_t relayPin = 3;
+const uint8_t drdyPin = 5;
+const uint8_t SO = 12;
+const uint8_t CS = 10;
+const uint8_t sck = 13;
+
+// user settings
+uint32_t settleTimeSec = 10;
+uint32_t testTimeSec = 500;
+const uint16_t samples = 500;
+const float inputSpan = 200;
+const float outputSpan = 1000;
+float outputStart = 0;
+float outputStep = 30;
+float tempLimit = 75;
+uint8_t debounce = 1;
+
+// variables
+float Input, Output, Setpoint = 50, Kp, Ki, Kd;
+
+MAX6675 module(sck, CS, SO); //SPI
+sTune tuner = sTune(&Input, &Output, tuner.ZN_PID, tuner.directIP, tuner.printOFF);
+QuickPID myPID(&Input, &Output, &Setpoint);
+
+void setup() {
+  pinMode(drdyPin, INPUT);
+  pinMode(relayPin, OUTPUT);
+  Serial.begin(115200);
+  while (!Serial) delay(10);
+  delay(3000);
+  Output = 0;
+  tuner.Configure(inputSpan, outputSpan, outputStart, outputStep, testTimeSec, settleTimeSec, samples);
+  tuner.SetEmergencyStop(tempLimit);
+}
+
+void loop() {
+  float optimumOutput = tuner.softPwm(relayPin, Input, Output, Setpoint, outputSpan, debounce);
+
+  switch (tuner.Run()) {
+    case tuner.sample: // active once per sample during test
+      Input = module.readCelsius();
+      tuner.plotter(Input, Output, Setpoint, 1, 3);
+      break;
+
+    case tuner.tunings: // active just once when sTune is done
+      tuner.GetAutoTunings(&Kp, &Ki, &Kd); // sketch variables updated by sTune
+      myPID.SetOutputLimits(0, outputSpan * 0.1);
+      myPID.SetSampleTimeUs(outputSpan * 1000 * 0.2);
+      debounce = 0; // switch to SSR optimum cycle mode
+      myPID.SetMode(myPID.Control::automatic); // the PID is turned on
+      myPID.SetProportionalMode(myPID.pMode::pOnMeas);
+      myPID.SetAntiWindupMode(myPID.iAwMode::iAwClamp);
+      myPID.SetTunings(Kp, Ki, Kd); // update PID with the new tunings
+      break;
+
+    case tuner.runPid: // active once per sample after tunings
+      Input = module.readCelsius();
+      myPID.Compute();
+      tuner.plotter(Input, optimumOutput, Setpoint, 1, 3);
+      break;
+  }
+}

library.json

@@ -1,6 +1,6 @@
 {
   "name": "sTune",
-  "version": "2.3.0",
+  "version": "2.3.1",
   "description": "Open loop PID autotuner using a novel s-curve inflection point test method. Tuning parameters are determined in about ½Tau on a first-order system with time delay. Full 5Tau testing and multiple serial output options are provided.",
   "keywords": "PID, autotune, autotuner, tuner, tune, stune, inflection, step",
   "repository":

library.properties

@@ -1,5 +1,5 @@
 name=sTune
-version=2.3.0
+version=2.3.1
 author=David Lloyd
 maintainer=David Lloyd <[email protected]>
 sentence=Open loop PID autotuner using a novel s-curve inflection point test method. 

src/sTune.cpp

@@ -1,5 +1,5 @@
 /****************************************************************************************
-   sTune Library for Arduino - Version 2.3.0
+   sTune Library for Arduino - Version 2.3.1
    by dlloydev https://github.com/Dlloydev/sTune
    Licensed under the MIT License.