add case temperature controller

case temperature controller: add library for DS18B20 temperature sensor as submodule

case temperature controller: add OneWire library for DS18B20 temperature sensor as submodule, turn temperature source code into own class

case temperature controller: add some more information to README

case temperature controller: turn fan code into own class

case temperature controller: remove loop from code

case temperature controller: turn printf into actual log

case temperature controller: remove unused libraries

case temperature controller: remove simulation (not needed anymore, temperature sensor works)

case temperature controller: cleanup

case temperature controller: add monitoring target to README

case temperature controller: add counter to controller so it doesn't execute on every loop through

case temperature controller: turn setSpeed into void function since it cannot return errors

case temperature controller: fix fan bug

case temperature controller: add circuit plan to README

case temperature controller: add recursive checkout of submodules to CICD

case temperature controller: assign correct pins for temperature sensor and fan

case temperature controller: renamend caseTemperatureController() to readTemperatureAndAdjustFanSpeed(), reformat caseTempController.cpp

case temperature controller: reformat temperature.cpp, fan.cpp

case temperature controller: include OneWire and Arduino-Temperature-Control-Library via pio package manager instead of submodules

.github/workflows/main.yml

@@ -23,6 +23,8 @@ jobs:
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
       - uses: actions/checkout@v2
+        with:
+          submodules: 'recursive'
       # Install python 3.x
       - uses: actions/setup-python@v2
         with:

.github/workflows/release.yml

@@ -11,6 +11,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
+        with:
+          submodules: 'recursive'
       - uses: actions/setup-python@v2
         with:
           python-version: '3.9.0'

firmware/README.md

@@ -1 +1,29 @@
-Firmware
+## Instructions for Linux
+
+- Install platformio.
+
+- Install (udev rules)[https://docs.platformio.org/en/latest/faq.html#platformio-udev-rules].
+
+- Add yourself to the dialout and tty group:
+
+```sh
+sudo usermod -a -G tty $USER
+sudo usermod -a -G dialout $USER
+sudo usermod -a -G plugdev $USER
+```
+
+Disconnect your board, then log out and log in again for the changes to take place. 
+
+Check if your ESP32 is connected:
+
+```sh
+ll /dev | grep ttyUSB*
+```
+
+You should then be able to flash the code onto your board by running
+
+```sh
+platformio run --target upload --target monitor
+```
+
+Afterwards, an access point should spawn (namend ```CleanAirDevice```). The password is ```12345678```. Afterwards, the configuration page should be reachable under e.g. ```http://172.217.28.1/_ac``` (you need to fill in the correct IP address, of course).

firmware/include/caseTempController.h

@@ -0,0 +1,40 @@
+//*****************************************//
+// includes                                //
+//*****************************************//
+#include "caseTempController/config.h"
+#include "caseTempController/temperature.h"
+#include "caseTempController/fan.h"
+
+//*****************************************//
+// class                                   //
+//*****************************************//
+class CaseTempController
+{
+    private:
+
+        // a history of the last TAU temperature errors
+        int temperature_errors[TAU];
+
+        // marks the place of the oldest info in the temperature_errors array
+        int* p_oldest_temperature_error;
+
+        // temperature sensor
+        TempSensor tempSensor;
+
+        // fan
+        Fan fan;
+
+        // counter used to check if controller should start measuring/calculating
+        int sleep_check;
+
+    public:
+
+        CaseTempController()
+        {
+            this->sleep_check = 0;
+        }
+
+        int init(void);
+
+        int readTemperatureAndAdjustFanSpeed(void);
+};

firmware/include/caseTempController/config.h

@@ -0,0 +1,12 @@
+//*****************************************//
+// configuration                           //
+//*****************************************//
+#define K_P                1        // proportional factor of the PID controller
+#define K_I                0.1      // integral factor of the PID controller
+#define K_D                0.5      // derivative factor of the PID controller
+#define TAU                20       // number of measurements viewed in calculation, reduce to save space and calculation times
+#define GOAL_TEMP          30       // goal temperature of 30°C
+#define TEMP_GPIO          26       // the GPIO data pin of the temperature sensor
+#define FAN_GPIO           23       // the PWM pin for fan control
+#define FAN_PWM_CHANNEL    0        // the PWM channel for fan control
+#define SLEEP              30000    // defines how many loop-throughs the controller will wait until measuring again

firmware/include/caseTempController/fan.h

@@ -0,0 +1,20 @@
+//*****************************************//
+// includes                                //
+//*****************************************//
+#include "Arduino.h"
+#include "config.h"
+
+
+//*****************************************//
+// class                                   //
+//*****************************************//
+class Fan
+{
+    public:
+
+        Fan() {}
+
+        void init(void);
+
+        void setSpeed(int fan_speed);
+};

firmware/include/caseTempController/temperature.h

@@ -0,0 +1,30 @@
+//*****************************************//
+// includes                                //
+//*****************************************//
+#include <DS18B20.h>
+#include "config.h"
+
+
+//*****************************************//
+// class                                   //
+//*****************************************//
+class TempSensor
+{
+    private:
+
+        OneWire* oneWire;
+
+        DS18B20* sensors;
+
+    public:
+
+        TempSensor()
+        {
+            oneWire = new OneWire(TEMP_GPIO);
+            sensors = new DS18B20(oneWire);
+        }
+
+        void init(void);
+
+        int read(void);
+};

firmware/platformio.ini

@@ -16,6 +16,8 @@ lib_deps =
 	hieromon/AutoConnect@^1.1.7
 	mathertel/RotaryEncoder@^1.3.0
 	lorol/LittleFS_esp32@1.0.0
+	paulstoffregen/OneWire@^2.3.5
+	robtillaart/DS18B20@^0.1.6
 monitor_speed = 115200
 monitor_filters = esp32_exception_decoder
 build_flags = 

firmware/src/caseTempController/README.md

@@ -0,0 +1,11 @@
+# Case Temperature Controller
+
+Sub-program for regulating a PWM controlled fan to keep a steady temperature within the case.
+
+Written for ESP32, Xinda Temperature Sensor, Noctua NF-A4x20 in C.
+
+This program is basically implementing a PID controller. To understand the underlying calculation, check the following wikipedia article: https://en.wikipedia.org/wiki/PID_controller#Alternative_nomenclature_and_forms
+
+# Circuit Diagram
+
+![](circuit.png)

firmware/src/caseTempController/caseTempController.cpp

@@ -0,0 +1,92 @@
+//*****************************************//
+// includes                                //
+//*****************************************//
+#include <stdbool.h>
+#include "caseTempController.h"
+
+//*****************************************//
+// functions                               //
+//*****************************************//
+int CaseTempController::init(void)
+{
+    // variables
+    int i;                          // loop counter
+    int temperature;                // current actual temperature
+    int temperature_error;          // the current difference between wished temperature and actual temperature
+
+    ESP_LOGD(TAG, "Configuration:");
+    ESP_LOGD(TAG, "   Proportional factor:             %i", K_P);
+    ESP_LOGD(TAG, "   Integral factor:                 %f", K_I);
+    ESP_LOGD(TAG, "   Differential factor:             %f", K_D);
+    ESP_LOGD(TAG, "   Viewed number of measurements:   %i", TAU);
+    ESP_LOGD(TAG, "   Goal temperature:                %i°C", GOAL_TEMP);
+    ESP_LOGD(TAG, "Initialize hardware.");
+    fan.init();
+    tempSensor.init();
+
+    ESP_LOGD(TAG, "Fill the temperature_errors array with inital values.");
+    for (i = 0; i < TAU; i++)
+    {
+        temperature = tempSensor.read();
+        temperature_errors[i] =  ((temperature_error = temperature - GOAL_TEMP) > 0 ? temperature_error : 0);
+    }
+    p_oldest_temperature_error = &temperature_errors[0];
+
+    return 0;
+}
+
+
+int CaseTempController::readTemperatureAndAdjustFanSpeed(void)
+{
+    if (sleep_check % SLEEP == 0)
+    {
+        // variables
+        int i;                              // loop counter
+        int temperature;                    // current actual temperature
+        int temperature_error;              // the current difference between wished temperature and actual temperature
+        int temperature_error_sum;          // the sum of the last TAU temperature errors
+        int pr, in, di;                     // proportional, integral, and differential adjustment
+        int fan_speed;                      // the fan speed that shall be set
+
+        // read in newest temperature error, put it in place of the oldest value
+        temperature = tempSensor.read();
+        *p_oldest_temperature_error = temperature_error = (temperature_error = temperature - GOAL_TEMP) > 0 ? temperature_error : 0;
+        ESP_LOGD(TAG, "Newest temperature error: %i°C", temperature_error);
+
+
+        // set p_oldest_temperature_error to next place in array
+        if (p_oldest_temperature_error == &temperature_errors[TAU - 1])
+            p_oldest_temperature_error = &temperature_errors[0];
+        else
+            p_oldest_temperature_error++;
+
+
+        // calculate proportional adjustment
+        pr = K_P * temperature_error;
+        ESP_LOGD(TAG, "Proportional adjustment: %i", pr);
+
+
+        // calculate integral adjustment
+        temperature_error_sum = 0;
+        for (i = 0; i < TAU; i++)
+            temperature_error_sum += temperature_errors[i];
+        in = K_I * temperature_error_sum;
+        ESP_LOGD(TAG, "Integral adjustment: %i", in);
+
+
+        // calculate differential adjustment
+        di = K_D * (temperature_error - *p_oldest_temperature_error);
+        ESP_LOGD(TAG, "Differential adjustment: %i", di);
+
+
+        // calculate and set new fan speed
+        fan_speed = pr + in + di;
+        if (fan_speed < 0) fan_speed = 0;
+        if (fan_speed > 100) fan_speed = 100;
+        ESP_LOGD(TAG, "Resulting fan speed: %i%%", fan_speed);
+        fan.setSpeed(fan_speed);
+    }
+
+    sleep_check++;
+    return 0;
+}

firmware/src/caseTempController/fan.cpp

@@ -0,0 +1,29 @@
+//*****************************************//
+// includes                                //
+//*****************************************//
+#include "caseTempController/fan.h"
+
+
+//*****************************************//
+// defines                                 //
+//*****************************************//
+#define FREQUENCY   25000   // the PWM frequency (fan runs best at 25kHz)
+#define RESOLUTION  8       // the duty cycle resolution in bits (8 means 255 steps)
+
+//*****************************************//
+// functions                               //
+//*****************************************//
+
+void Fan::init(void)
+{
+    ledcSetup(0, FREQUENCY, RESOLUTION);
+    ledcAttachPin(FAN_GPIO, FAN_PWM_CHANNEL);
+    setSpeed(0);
+    return;
+}
+
+
+void Fan::setSpeed(int fan_speed)
+{
+    ledcWrite(FAN_PWM_CHANNEL, (int)(fan_speed * (255 / 100)));
+}

firmware/src/caseTempController/temperature.cpp

@@ -0,0 +1,23 @@
+//*****************************************//
+// includes                                //
+//*****************************************//
+#include "caseTempController/temperature.h"
+
+//*****************************************//
+// functions                               //
+//*****************************************//
+void TempSensor::init(void)
+{
+    (*sensors).begin();
+    return;
+}
+
+
+int TempSensor::read(void)
+{
+        int temperature = 0;
+        (*sensors).requestTemperatures();
+        temperature = (*sensors).getTempC();
+        ESP_LOGD(TAG, "Newest temperature: %i°C", temperature);
+        return temperature;
+}

firmware/src/main.cpp

@@ -20,6 +20,7 @@
 #include "rotary.h"
 #include "operationHourCounter.h"
 #include "updateService.h"
+#include "caseTempController.h"
 
 void setFanSpeed(int speed);
 
@@ -40,6 +41,9 @@ OperationHourCounter operationHourCounter;
 // Define the fans controller.
 FanController fanController;
 
+// Define case temperature controller.
+CaseTempController caseTempController;
+
 // Define the adpter to handle hardware related io things.
 Rotary rotary;
 
@@ -196,6 +200,8 @@ void setup()
   rotary.setup(jsonHandler, setFanSpeed);
   updateService.setup(jsonHandler);
 
+  caseTempController.init();
+
   configureNetwork();
 
   ESP_LOGI(TAG, "Setup complete %s", TAG);
@@ -222,4 +228,7 @@ void loop()
 
   // handlet the current rotary position
   rotary.handle();
+
+  // regulate case temperature
+  caseTempController.readTemperatureAndAdjustFanSpeed();
 } // loop