From 4b1ef018ddab7f6e3be48b7430fc90bb3e8a8a6c Mon Sep 17 00:00:00 2001
From: Evgenii Meshcheriakov <evgeny.meshcheryakov@gmail.com>
Date: Wed, 19 Oct 2022 09:46:55 +0300
Subject: [PATCH] StateHandler: first version of pid() for fan

---
 StateHandler/inc/StateHandler.h     |  9 ++++++++-
 StateHandler/src/StateHandler.cpp   | 17 ++++++++---------
 esp-vent-main/src/esp-vent-main.cpp |  2 +-
 3 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/StateHandler/inc/StateHandler.h b/StateHandler/inc/StateHandler.h
index 97288d5..9c17622 100644
--- a/StateHandler/inc/StateHandler.h
+++ b/StateHandler/inc/StateHandler.h
@@ -105,7 +105,14 @@ private:
   void SetState (state_pointer newstate);
   bool current_mode;
   Counter value[2] = { { 0, 100 }, { 0, 120 } };
-  Counter fan_speed = {80, 1000};
+  /* motor of fan starts at value 90. probably because of some
+   * weigh of fan, so voltage within range of 0-89 is not
+   * sufficient to start motor.
+   * TODO: Value 89 should be scaled to 0 at some point */
+  Counter fan_speed = {89, 1000};
+  /*integral controller for PID. should be global, since it
+   * accumulates error signals encountered since startup*/
+  int integral = 0;
   int saved_set_value[2] = { 0, 0 };
   int saved_curr_value[2] = { 0, 0 };
   LiquidCrystal *_lcd;
diff --git a/StateHandler/src/StateHandler.cpp b/StateHandler/src/StateHandler.cpp
index 53c104a..7ff451f 100644
--- a/StateHandler/src/StateHandler.cpp
+++ b/StateHandler/src/StateHandler.cpp
@@ -134,13 +134,8 @@ StateHandler::stateAuto (const Event &event)
       break;
     case Event::eTick:
       save (event.value, value[AUTO].getCurrent (), AUTO);
-      if(saved_curr_value[AUTO] < saved_set_value[AUTO]) {
-    	  fan_speed.inc();
-    	  this->A01->write(fan_speed.getCurrent());
-      } else if(saved_curr_value[AUTO] > saved_set_value[AUTO]){
-    	  fan_speed.dec();
-    	  this->A01->write(fan_speed.getCurrent());
-      }
+      pid();
+      this->A01->write(fan_speed.getCurrent());
       break;
     }
 }
@@ -182,8 +177,12 @@ StateHandler::save (int eventValue, int counterValue, size_t mode)
 }
 
 void StateHandler::pid () {
-	int integral = 0, error = 0;
+	float kP = 0.7, kI = 0.7, kD = 0.7;
+	int error = 0, last_error = 0, derivative = 0;
 	error = saved_curr_value[AUTO] - saved_set_value[AUTO];
-
+	last_error = error;
+	integral += error;
+	derivative = error - last_error;
+	fan_speed.setInit((kP*error) + (kI*integral) + (kD * derivative));
 }
 
diff --git a/esp-vent-main/src/esp-vent-main.cpp b/esp-vent-main/src/esp-vent-main.cpp
index ff404df..5ebf321 100644
--- a/esp-vent-main/src/esp-vent-main.cpp
+++ b/esp-vent-main/src/esp-vent-main.cpp
@@ -93,7 +93,7 @@ main (void)
        * TODO:
        * - Update current pressure to eTick
        */
-      if(pressure_time == 100) {
+      if(pressure_time == 80) {
 		  pressure = sens.getPressure();
 		  pressure_time = 0;
       }