Update

- Fixed REVERSE acting controller mode.
- now using src folder for source code
- replaced defines with enumerated types and inline functions

Author: Dlloydev

LICENSE

@@ -1,4 +1,3 @@
-Copyright 2011-2017 Brett Beauregard <[email protected]> brettbeauregard.com
 Copyright 2021 David Lloyd <[email protected]>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of
@@ -16,4 +15,4 @@ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
-CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

@@ -47,6 +47,10 @@ The new `kpi` and `kpd` parameters are calculated in the `SetTunings()` function
  kpd = kp * (1 - pOn) + kd;
 ```
 
+### Controller Action
+
+If a positive error increases the controller's output, the controller is said to be direct acting (i.e. heating process). When a positive error decreases the controller's output, the controller is said to be reverse acting (i.e. cooling process). Since the PWM and ADC peripherals on microcontrollers only operate with positive values, QuickPID only uses positive values for Input, Output and Setpoint. When the controller is set to `REVERSE` acting, the sign of the `error` and `dInput` (derivative of Input) is internally changed. All operating ranges and limits remain the same. To simulate a `REVERSE` acting process from a process that's  `DIRECT` acting, the Input value needs to be "flipped". That is, if your reading from a 10-bit ADC with 0-1023 range, the input value used is (1023 - reading). See the example [AutoTune_RC_Filter.ino](https://github.com/Dlloydev/QuickPID/blob/master/examples/AutoTune_RC_Filter/AutoTune_RC_Filter.ino) for details.
+
 ### Functions
 
 #### QuickPID_Constructor
@@ -180,6 +184,12 @@ Use this link for reference. Note that if you're using QuickPID, there's no need
 
 #### [![arduino-library-badge](https://www.ardu-badge.com/badge/QuickPID.svg?)](https://www.ardu-badge.com/QuickPID)
 
+#### Version 2.2.7
+
+- Fixed REVERSE acting controller mode.
+- now using src folder for source code 
+- replaced defines with enumerated types and inline functions
+
 #### Version 2.2.6
 
 - Changed Input, Output and Setpoint parameters to float.

examples/AutoTune_RC_Filter/AutoTune_RC_Filter.ino

@@ -30,7 +30,11 @@ unsigned long timeout = 120;  // AutoTune timeout (sec)
 float Input, Output, Setpoint;
 float Kp = 0, Ki = 0, Kd = 0;
 
-QuickPID myQuickPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, POn, DIRECT);
+// choose controller direction:
+// DIRECT: Input increases when the output is increased or the error is positive (heating).
+// REVERSE: Input decreases when the output is increased or when the error is positive (cooling).
+QuickPID myQuickPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, POn, QuickPID::DIRECT);
+//QuickPID myQuickPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, POn, QuickPID::REVERSE);
 
 void setup()
 {
@@ -39,8 +43,8 @@ void setup()
 
   myQuickPID.AutoTune(inputPin, outputPin, tuningRule, Print, timeout);
   myQuickPID.SetTunings(myQuickPID.GetKp(), myQuickPID.GetKi(), myQuickPID.GetKd());
-  myQuickPID.SetSampleTimeUs(5000); // recommend 5000µs (5ms) minimum
-  myQuickPID.SetMode(AUTOMATIC);
+  myQuickPID.SetSampleTimeUs(4000); // 4ms
+  myQuickPID.SetMode(QuickPID::AUTOMATIC);
   Setpoint = 700;
 
   if (Print == 1) {
@@ -66,7 +70,11 @@ void loop()
   Serial.print("Output:");    Serial.print(Output);    Serial.print(",");
   Serial.println(",");
 
-  Input = myQuickPID.analogReadFast(inputPin);
+  if (myQuickPID.GetDirection() == QuickPID::REVERSE) {
+    Input = (1023 - myQuickPID.analogReadFast(inputPin)); // simulate reverse acting controller (cooling)
+  } else {
+    Input = (myQuickPID.analogReadFast(inputPin));
+  }
   myQuickPID.Compute();
   analogWrite(outputPin, Output);
 }

examples/QuickPID_AdaptiveTunings/QuickPID_AdaptiveTunings.ino

@@ -24,7 +24,7 @@ float aggPOn = 1.0; // Range is 0.0 to 1.0 (1.0 is 100% P on Error, 0% P on Meas
 float consPOn = 0.0; // Range is 0.0 to 1.0 (0.0 is 0% P on Error, 100% P on Measurement)
 
 //Specify the links and initial tuning parameters
-QuickPID myQuickPID(&Input, &Output, &Setpoint, consKp, consKi, consKd, aggPOn, DIRECT);
+QuickPID myQuickPID(&Input, &Output, &Setpoint, consKp, consKi, consKd, aggPOn, QuickPID::DIRECT);
 
 void setup()
 {
@@ -33,7 +33,7 @@ void setup()
   Setpoint = 100;
 
   //turn the PID on
-  myQuickPID.SetMode(AUTOMATIC);
+  myQuickPID.SetMode(QuickPID::AUTOMATIC);
 }
 
 void loop()

examples/QuickPID_Basic/QuickPID_Basic.ino

@@ -14,7 +14,7 @@ float Setpoint, Input, Output;
 //Specify the links and initial tuning parameters
 float Kp = 2, Ki = 5, Kd = 1;
 
-QuickPID myQuickPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, DIRECT);
+QuickPID myQuickPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, QuickPID::DIRECT);
 
 void setup()
 {
@@ -23,7 +23,7 @@ void setup()
   Setpoint = 100;
 
   //turn the PID on
-  myQuickPID.SetMode(AUTOMATIC);
+  myQuickPID.SetMode(QuickPID::AUTOMATIC);
 }
 
 void loop()

examples/QuickPID_PonM/QuickPID_PonM.ino

@@ -13,7 +13,7 @@ float Setpoint, Input, Output;
 float POn = 0.0; // Range is 0.0 to 1.0 (0.0 is 0% P on Error, 100% P on Measurement)
 
 //Specify the links and initial tuning parameters
-QuickPID myQuickPID(&Input, &Output, &Setpoint, 2, 5, 1, POn, DIRECT);
+QuickPID myQuickPID(&Input, &Output, &Setpoint, 2, 5, 1, POn, QuickPID::DIRECT);
 
 void setup()
 {
@@ -22,7 +22,7 @@ void setup()
   Setpoint = 100;
 
   //turn the PID on
-  myQuickPID.SetMode(AUTOMATIC);
+  myQuickPID.SetMode(QuickPID::AUTOMATIC);
 }
 
 void loop()

examples/QuickPID_RelayOutput/QuickPID_RelayOutput.ino

@@ -28,7 +28,7 @@ float Setpoint, Input, Output;
 float Kp = 2, Ki = 5, Kd = 1;
 float POn = 0.0; // Range is 0.0 to 1.0 (0.0 is 0% P on Error, 100% P on Measurement)
 
-QuickPID myQuickPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, POn, DIRECT);
+QuickPID myQuickPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, POn, QuickPID::DIRECT);
 
 unsigned int WindowSize = 5000;
 unsigned int minWindow = 500;
@@ -46,7 +46,7 @@ void setup()
   myQuickPID.SetOutputLimits(0, WindowSize);
 
   //turn the PID on
-  myQuickPID.SetMode(AUTOMATIC);
+  myQuickPID.SetMode(QuickPID::AUTOMATIC);
 }
 
 void loop()

keywords.txt

@@ -7,6 +7,8 @@
 ##########################################
 
 QuickPID	KEYWORD1
+mode_t	KEYWORD1
+direction_t	KEYWORD1
 analog_write_channel_t	KEYWORD1
 
 ##########################################

library.json

@@ -3,7 +3,7 @@
   "keywords": "PID, controller, signal",
   "description": "A fast fixed/floating point PID controller with AutoTune and 9 tuning rules to choose from. This controller can automatically determine and set tuning parameters. Compatible with most Arduino and ESP32 boards.",
   "license": "MIT",
-  "version": "2.2.6",
+  "version": "2.2.7",
   "url": "https://github.com/Dlloydev/QuickPID",
   "include": "QuickPID",
   "authors":

library.properties

@@ -1,5 +1,5 @@
 name=QuickPID
-version=2.2.6
+version=2.2.7
 author=David Lloyd
 maintainer=David Lloyd <[email protected]>
 sentence=A fast fixed/floating point PID controller with AutoTune and 9 tuning rules to choose from.