add PID

.vscode/extensions.json

@@ -1,8 +1,10 @@
 {
+    // See http://go.microsoft.com/fwlink/?LinkId=827846
+    // for the documentation about the extensions.json format
     "recommendations": [
         "platformio.platformio-ide"
     ],
     "unwantedRecommendations": [
         "ms-vscode.cpptools-extension-pack"
     ]
-}
+}

src/main.cpp

@@ -8,6 +8,7 @@
 #include <ElegantOTA.h>
 
 #include "secrets.h"
+#include "pid.h"
 
 AsyncWebServer server(80);
 AsyncWebSocket ws("/ws");
@@ -18,7 +19,7 @@ String jsonString;
 
 // Timer variables
 unsigned long lastTime = 0;
-unsigned long timerDelay = 250;
+unsigned long timerDelay = 500;
 
 int relay = 21;
 int thermoDO = 19;
@@ -37,9 +38,12 @@ unsigned long lastSwitch = 0;
 unsigned long autoSwitchDelay = 20000; // 20s
 float pwmSwitchDelayOn = 4000;         // 4s
 float pwmSwitchDelayOff = 7000;        // 7s
+float power = 0;
 
 String mode = "off";
 
+PIDController pid(1.0, 0.5, 1.0, 100.0, 0.0, 50.0); // Kp, Ki, Kd, max, min, integ_max
+
 // Get Sensor Readings and return JSON object
 String getSensorReadings()
 {
@@ -60,6 +64,9 @@ String getSensorReadings()
   readings["derived_overshoot"] = derivedOverShoot;
   readings["derived_undershoot"] = derivedUnderShoot;
   readings["mode"] = mode;
+  readings["pid"] = power;
+  readings["pwm_on"] = pwmSwitchDelayOn;
+  readings["pwm_off"] = pwmSwitchDelayOff;
 
   serializeJson(readings, jsonString);
   return jsonString;
@@ -133,6 +140,7 @@ void handleWebSocketMessage(void *arg, uint8_t *data, size_t len)
     {
       String target = message.substring(15, 18);
       targetTemp = target.toFloat();
+      pid.setSetpoint(targetTemp);
       Serial.printf("\nTarget temp set to ");
       Serial.print(targetTemp);
       Serial.printf("°C");
@@ -147,6 +155,10 @@ void handleWebSocketMessage(void *arg, uint8_t *data, size_t len)
       {
         mode = "pwm";
       }
+      else if (message.indexOf("pid") > 0)
+      {
+        mode = "pid";
+      }
       else
       {
         mode = "off";
@@ -265,6 +277,37 @@ void regulateRelais()
       }
     }
   }
+  if (mode == "pid")
+  {
+    // output = Kp×error + Ki×∫error×dt + Kd×(Δerror/Δt)`[^2][^5]
+    power = pid.compute(temperature);
+    pwmSwitchDelayOff = (pwmSwitchDelayOn / (power / 100)) - pwmSwitchDelayOn;
+
+    if (pwmSwitchDelayOff > 0)
+    {
+      if ((millis() - lastSwitch) > pwmSwitchDelayOn)
+      {
+        if (digitalRead(relay) == HIGH)
+        {
+          digitalWrite(relay, LOW);
+          lastSwitch = millis();
+        }
+      }
+    }
+
+    if (pwmSwitchDelayOff > 0)
+    {
+
+      if ((millis() - lastSwitch) > pwmSwitchDelayOff)
+      {
+        if (digitalRead(relay) == LOW)
+        {
+          digitalWrite(relay, HIGH);
+          lastSwitch = millis();
+        }
+      }
+    }
+  }
 }
 
 void setup()
@@ -282,6 +325,10 @@ void setup()
 
   server.serveStatic("/", LittleFS, "/");
 
+  // Create PID controller instance
+  pid.setSetpoint(targetTemp);
+  pid.setDt(4);
+
   ElegantOTA.begin(&server);
 
   // Start server

src/pid.cpp

@@ -0,0 +1,60 @@
+#include "pid.h"
+
+double PIDController::clamp(double value, double min_val, double max_val) const
+{
+    if (value < min_val)
+        return min_val;
+    if (value > max_val)
+        return max_val;
+    return value;
+}
+
+PIDController::PIDController(double Kp, double Ki, double Kd,
+                             double max_out, double min_out, double integ_max)
+    : kp(Kp), ki(Ki), kd(Kd), setpoint(0.0), integral(0.0),
+      prev_error(0.0), max_output(max_out), min_output(min_out),
+      integral_max(integ_max), dt(0.1), first_run(true) {}
+
+void PIDController::setSetpoint(double sp)
+{
+    setpoint = sp;
+}
+
+void PIDController::setDt(double sample_time)
+{
+    dt = sample_time;
+}
+
+double PIDController::compute(double current_temp)
+{
+    double error = setpoint - current_temp;
+
+    // Proportional
+    double p_term = kp * error;
+
+    // Integral + anti-windup
+    integral += ki * error * dt;
+    integral = clamp(integral, -integral_max, integral_max);
+
+    // Derivative
+    double d_term = 0.0;
+    if (!first_run)
+    {
+        d_term = kd * (error - prev_error) / dt;
+    }
+    first_run = false;
+
+    // Output
+    double output = p_term + integral + d_term;
+    output = clamp(output, min_output, max_output);
+
+    prev_error = error;
+    return output;
+}
+
+void PIDController::reset()
+{
+    integral = 0.0;
+    prev_error = 0.0;
+    first_run = true;
+}

src/pid.h

@@ -0,0 +1,25 @@
+#ifndef PID_CONTROLLER_H
+#define PID_CONTROLLER_H
+
+class PIDController
+{
+private:
+    double kp, ki, kd, setpoint, integral, prev_error;
+    double max_output, min_output, integral_max, dt;
+    bool first_run;
+
+    // Clamp function (C++11 compatible)
+    double clamp(double value, double min_val, double max_val) const;
+
+public:
+    PIDController(double Kp, double Ki, double Kd,
+                  double max_out = 100.0, double min_out = 0.0,
+                  double integ_max = 50.0);
+
+    void setSetpoint(double sp);
+    void setDt(double sample_time);
+    double compute(double current_temp);
+    void reset();
+};
+
+#endif

src/routes/+page.svelte

@@ -16,25 +16,28 @@
 
 	const now = new Date();
 
-	let mode = 'off';
-	let temp = 300;
-	let relais = 0;
-	let targetTemp = 300;
+	let mode = $state('off');
+	let temp = $state(300);
+	let relais = $state(0);
+	let targetTemp = $state(300);
 	let setOverShoot = 20;
 	let setUnderShoot = 20;
-	let targetTempOverShoot = targetTemp;
-	let targetTempUnderShoot = targetTemp;
+	let targetTempOverShoot = $state(targetTemp);
+	let targetTempUnderShoot = $state(targetTemp);
+	let calculatedPidOutput = $state(0);
 
 	let lastSwitch = new Date();
 	let lastSwitchDuration = 0;
 
 	let canvas: HTMLCanvasElement;
 
-	let pauseGraphUpdate = false;
+	let pauseGraphUpdate = $state(false);
 	let spoofInterval = 250;
 	let speedFactor = 250 / spoofInterval;
 	const switchDelay = (30 / speedFactor) * 1000;
+	let pwmOn = $state(4);
 	let pwmOnDelay = (4 / speedFactor) * 1000;
+	let pwmOff = $state(7);
 	let pwmOffDelay = (7 / speedFactor) * 1000;
 
 	let maxValues = 4 * 2 * 60 * 60; // 120 minutes (4 values/sec)
@@ -352,6 +355,12 @@
 				targetTempOverShoot = myObj[key];
 			} else if (key === 'derived_undershoot') {
 				targetTempUnderShoot = myObj[key];
+			} else if (key === 'pid') {
+				calculatedPidOutput = myObj[key];
+			} else if (key === 'pwm_on') {
+				pwmOn = Number(myObj[key]) / 1000;
+			} else if (key === 'pwm_off') {
+				pwmOff = Number(myObj[key]) / 1000;
 			} else if (key === 'mode') {
 				mode = myObj[key];
 				modeSpan.innerText = mode;
@@ -402,6 +411,7 @@
 		const target = e.target as HTMLTextAreaElement;
 		let value = Number(target?.value);
 		console.log('Changed pwm on to ' + value);
+		pwmOn = value;
 		if (!import.meta.env.DEV) {
 			ws.send('setPWMOn: ' + pad(value, 3));
 		} else {
@@ -413,6 +423,7 @@
 		const target = e.target as HTMLTextAreaElement;
 		let value = Number(target?.value);
 		console.log('Changed pwm off to ' + value);
+		pwmOff = value;
 		if (!import.meta.env.DEV) {
 			ws.send('setPWMOff: ' + pad(value, 3));
 		} else {
@@ -486,7 +497,7 @@
 	<div class="graph">
 		<div class="plot-wrapper w-[800px]">
 			<div id="plot"></div>
-			<canvas bind:this={canvas} id="acquisitions"></canvas>
+			<canvas bind:this={canvas} id="crusty"></canvas>
 		</div>
 	</div>
 	<div class="card-grid settings">
@@ -498,7 +509,7 @@
 					type="number"
 					min="0"
 					max="600"
-					placeholder="300"
+					value={targetTemp}
 					id="target_temperature"
 					onchange={changeTargetTemp}
 				/>
@@ -513,11 +524,12 @@
 				<select class="rounded" name="modes" id="mode_selector" onchange={changeMode}>
 					<option value="auto_switch">Auto Switch</option>
 					<option value="pwm">PWM</option>
+					<option value="pid">PID</option>
 					<option value="off" selected>Manual</option>
 				</select>
 			</p>
 			{#if mode === 'pwm'}
-				<div class="gap-15 mt-2 flex items-center">
+				<div class="mt-2 flex items-center gap-15">
 					<div>on</div>
 					<div>off</div>
 				</div>
@@ -528,7 +540,7 @@
 						type="number"
 						min="0"
 						max="120"
-						placeholder="4"
+						bind:value={pwmOn}
 						id="pwm_on"
 						onchange={changePwmOn}
 					/>
@@ -538,12 +550,24 @@
 						type="number"
 						min="0"
 						max="120"
-						placeholder="7"
+						bind:value={pwmOff}
 						id="pwm_off"
 						onchange={changePwmOff}
 					/>
 					<label for="pwm_off"> s </label>
 				</div>
+				<div class="mt-3 flex items-center gap-1">
+					{((pwmOn / (pwmOn + pwmOff)) * 100).toFixed(0)}%, {(
+						(pwmOn / (pwmOn + pwmOff)) *
+						1200
+					).toFixed(0)}W
+				</div>
+			{/if}
+			{#if mode === 'pid'}
+				<div class="mt-3 flex items-center gap-1">
+					PID: {calculatedPidOutput.toFixed(0)}% {(calculatedPidOutput * 12).toFixed(0)}W
+				</div>
+				<div>ON:{pwmOn.toFixed(2)}s OFF:{pwmOff.toFixed(2)}s</div>
 			{/if}
 		</div>
 		<div class="card flex cursor-pointer gap-2">

src/tmp.json

@@ -0,0 +1,9 @@
+{
+    "m.homeserver": {
+        "base_url": "tjet.nl"
+    },
+    "org.matrix.msc2965.authentication": {
+        "issuer": "https://account.tjet.nl/",
+        "account": "https://account.tjet.nl/account/"
+    }
+}