Update

Update documentation, Wiki and examples

Author: Dlloydev

README.md

@@ -4,7 +4,9 @@ This is an open loop PID autotuner using a novel s-curve inflection point test m
 
 #### Reaction Curve Inflection Point Tuning Method
 
-This tuning method determines the process gain, dead time and time constant by doing a shortened step test that ends just after the [inflection point](http://en.wikipedia.org/wiki/Inflection_point) has been reached. From here, the apparent maximum PV (input) is mathematically determined and the  controller's tuning parameters are calculated. Test duration is typically only ½Tau.  
+This tuning method determines the process gain, dead time and time constant by doing a shortened step test that ends just after the [inflection point](http://en.wikipedia.org/wiki/Inflection_point) has been reached. From here, the apparent maximum PV (input) is mathematically determined and the  controller's tuning parameters are calculated. Test duration is typically only ½Tau.
+
+- See [**WiKi**](https://github.com/Dlloydev/sTune/wiki) for test results and more.
 
 #### Inflection Point Discovery
 

examples/Autotune_PID_v1/Autotune_PID_v1.ino

@@ -38,25 +38,25 @@ sTune tuner = sTune(&input, &output, tuner.zieglerNicholsPID, tuner.directIP, tu
                                            noOvershootPID
 */
 void setup() {
-  analogReference(EXTERNAL);
+  analogReference(EXTERNAL); // AVR
   Serial.begin(115200);
   analogWrite(outputPin, outputStart);
   tuner.Configure(outputStart, outputStep, testTimeSec, settleTimeSec, samples);
 }
 
 void loop() {
 
-  switch (tuner.Run()) {
+  switch (tuner.Run()) {  // active while sTune is testing (non-blocking)
     case tuner.inOut:
       input = (analogRead(inputPin) / mvResolution) - bias;
       analogWrite(outputPin, output);
       break;
 
-    case tuner.tunings:
-      tuner.SetAutoTunings(&kp, &ki, &kd);
-      myPID.SetMode(AUTOMATIC);
-      myPID.SetSampleTime((testTimeSec * 1000) / samples);
-      myPID.SetTunings(kp, ki, kd);
+    case tuner.tunings:                                      // active just once when sTune is done
+      tuner.SetAutoTunings(&kp, &ki, &kd);                   // sketch variables are updated by sTune
+      myPID.SetMode(AUTOMATIC);                              // the PID is turned on (automatic)
+      myPID.SetSampleTime((testTimeSec * 1000) / samples);   // PID sample rate
+      myPID.SetTunings(kp, ki, kd);                          // update PID with the new tunings
       break;
 
     case tuner.runPid:
@@ -65,4 +65,5 @@ void loop() {
       analogWrite(outputPin, Output);
       break;
   }
+  // put your main code here, to run repeatedly
 }

examples/Autotune_QuickPID/Autotune_QuickPID.ino

@@ -41,31 +41,31 @@ sTune tuner = sTune(&Input, &Output, tuner.zieglerNicholsPID, tuner.directIP, tu
                                            noOvershootPID
 */
 void setup() {
-  analogReference(EXTERNAL);
+  analogReference(EXTERNAL); // AVR
   Serial.begin(115200);
   analogWrite(outputPin, outputStart);
   tuner.Configure(outputStart, outputStep, testTimeSec, settleTimeSec, samples);
 }
 
 void loop() {
-
-  switch (tuner.Run()) {
+  switch (tuner.Run()) {  // active while sTune is testing (non-blocking)
     case tuner.inOut:
       Input = (analogRead(inputPin) / mvResolution) - bias;
       analogWrite(outputPin, Output);
       break;
 
-    case tuner.tunings:
-      tuner.SetAutoTunings(&Kp, &Ki, &Kd);
-      myPID.SetMode(myPID.Control::automatic);
-      myPID.SetSampleTimeUs((testTimeSec * 1000000) / samples);
-      myPID.SetTunings(Kp, Ki, Kd);
+    case tuner.tunings:                                         // active just once when sTune is done
+      tuner.SetAutoTunings(&Kp, &Ki, &Kd);                      // sketch variables are updated by sTune
+      myPID.SetMode(myPID.Control::automatic);                  // the PID is turned on (automatic)
+      myPID.SetSampleTimeUs((testTimeSec * 1000000) / samples); // PID sample rate
+      myPID.SetTunings(Kp, Ki, Kd);                             // update PID with the new tunings
       break;
 
-    case tuner.runPid:
+    case tuner.runPid:  // this case runs continuously after case "tunings" (non-blocking)
       Input = (analogRead(inputPin) / mvResolution) - bias;
       myPID.Compute();
       analogWrite(outputPin, Output);
       break;
   }
+  // put your main code here, to run repeatedly
 }

library.json

@@ -1,6 +1,6 @@
 {
   "name": "sTune",
-  "version": "1.0.2",
+  "version": "1.0.3",
   "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=1.0.2
+version=1.0.3
 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 1.0.2
+   sTune Library for Arduino - Version 1.0.3
    by dlloydev https://github.com/Dlloydev/sTune
    Licensed under the MIT License.
 
@@ -85,6 +85,7 @@ uint8_t sTune::Run() {
             if (pvDiff > epsilon && pvDiff < pvRes) pvRes = pvDiff;  // check buffered input resolution
 
             if (sampleCount == 0) {                     // initialize at first sample
+              *_output = _outputStart;
               tangent.init(pvInst);
               pvAvg = pvInst;
               pvStart = pvInst;
@@ -198,6 +199,7 @@ uint8_t sTune::Run() {
         }
       } else {  // settling
         if (usElapsed >= _samplePeriodUs) {
+          *_output = _outputStart;
           usPrev = usNow;
           pvInst = *_input;
           if (_serialMode == printALL || _serialMode == printDEBUG) {