Moved measuring and publish into the Measurements class. Further code cleanup steps will follow on this, but committing since we have a nicely working version now.

src/Data/DataController.cpp

@@ -6,9 +6,6 @@
 
 DataController *DataController::_instance = nullptr;
 
-/**
- * Fetch the DoughData singleton.
- */
 DataController *DataController::Instance()
 {
     if (DataController::_instance == nullptr)
@@ -18,9 +15,24 @@ DataController *DataController::Instance()
     return DataController::_instance;
 }
 
-DataController::DataController() : _temperatureMeasurements(TEMPERATURE_AVG_LOOKBACK),
+DataController::DataController() : _temperatureMeasurements(
-                                   _humidityMeasurements(HUMIDITY_AVG_LOOKBACK),
+                                       "temperature",
-                                   _distanceMeasurements(DISTANCE_AVG_LOOKBACK),
+                                       readTemperature,
+                                       TEMPERATURE_AVG_LOOKBACK,
+                                       TEMPERATURE_SIGNIFICANT_CHANGE,
+                                       PUBLISH_INTERVAL),
+                                   _humidityMeasurements(
+                                       "humidity",
+                                       readHumidity,
+                                       HUMIDITY_AVG_LOOKBACK,
+                                       HUMIDITY_SIGNIFICANT_CHANGE,
+                                       PUBLISH_INTERVAL),
+                                   _distanceMeasurements(
+                                       "distance",
+                                       readDistance,
+                                       DISTANCE_AVG_LOOKBACK,
+                                       DISTANCE_SIGNIFICANT_CHANGE,
+                                       PUBLISH_INTERVAL),
                                    _logger("DATA")
 {
     _ui = DoughUI::Instance();
@@ -100,7 +112,6 @@ void DataController::loop()
     if (isConfigured())
     {
         _sample();
-        _publish();
     }
 }
 
@@ -135,52 +146,18 @@ void DataController::_sample()
         _ui->suspend();
 
         // Take a sample.
-        Measurement m;
         switch (_sampleType)
         {
         case SAMPLE_TEMPERATURE:
-            m = _sensors->readTemperature();
+            _temperatureMeasurements.process();
-            _temperatureMeasurements.add(m);
-            if (_temperatureLastPublished.ok && m.ok && _temperatureLastPublished.value != m.value)
-            {
-                if (m.value == _temperatureMeasurements.getAverage().value ||
-                    abs(_temperatureLastPublished.value - m.value) > TEMPERATURE_SIGNIFICANT_CHANGE) {
-                    _publishTemperature();
-                }
-            }
-            else if (_temperatureLastPublished.ok == false && m.ok) {
-                _publishTemperature();
-            }
             _sampleType = SAMPLE_HUMIDITY;
             break;
         case SAMPLE_HUMIDITY:
-            m = _sensors->readHumidity();
+            _humidityMeasurements.process();
-            _humidityMeasurements.add(m);
-            if (_humidityLastPublished.ok && m.ok && _humidityLastPublished.value != m.value)
-            {
-                if (m.value == _humidityMeasurements.getAverage().value ||
-                    abs(_humidityLastPublished.value - m.value) > HUMIDITY_SIGNIFICANT_CHANGE) {
-                    _publishHumidity();
-                }
-            }
-            else if (_humidityLastPublished.ok == false && m.ok) {
-                _publishHumidity();
-            }
             _sampleType = SAMPLE_DISTANCE;
             break;
         case SAMPLE_DISTANCE:
-            m = _sensors->readDistance();
+            _distanceMeasurements.process();
-            _distanceMeasurements.add(m);
-            if (_distanceLastPublished.ok && m.ok && _distanceLastPublished.value != m.value)
-            {
-                if (m.value == _distanceMeasurements.getAverage().value ||
-                    abs(_distanceLastPublished.value - m.value) > DISTANCE_SIGNIFICANT_CHANGE) {
-                    _publishDistance();
-                }
-            }
-            else if (_distanceLastPublished.ok == false && m.ok) {
-                _publishDistance();
-            }
             break;
         }
 
@@ -194,42 +171,3 @@ void DataController::_sample()
         }
     }
 }
-
-void DataController::_publish()
-{
-    if (_lastPublish == 0 || millis() - _lastPublish > PUBLISH_INTERVAL)
-    {
-        _lastPublish = millis();
-        _publishTemperature();
-        _publishHumidity();
-        _publishDistance();
-        _ui->led1.dip()->fast();
-    }
-}
-
-void DataController::_publishTemperature()
-{
-    auto m = _temperatureMeasurements.getLast();
-    _temperatureLastPublished.ok = m.ok;
-    _temperatureLastPublished.value = m.value;
-    _mqtt->publish("temperature", m);
-    _mqtt->publish("temperature/average", _temperatureMeasurements.getAverage());
-}
-
-void DataController::_publishHumidity()
-{
-    auto m = _humidityMeasurements.getLast();
-    _humidityLastPublished.ok = m.ok;
-    _humidityLastPublished.value = m.value;
-    _mqtt->publish("humidity", _humidityMeasurements.getLast());
-    _mqtt->publish("humidity/average", _humidityMeasurements.getAverage());
-}
-
-void DataController::_publishDistance()
-{
-    auto m = _distanceMeasurements.getLast();
-    _distanceLastPublished.ok = m.ok;
-    _distanceLastPublished.value = m.value;
-    _mqtt->publish("distance", _distanceMeasurements.getLast());
-    _mqtt->publish("distance/average", _distanceMeasurements.getAverage());
-}

src/Data/DataController.h

@@ -14,7 +14,7 @@
 // in the average computation.
 #define TEMPERATURE_AVG_LOOKBACK 6       // making this a 3 minute average
 #define HUMIDITY_AVG_LOOKBACK 6          // making this a 3 minute average
-#define DISTANCE_AVG_LOOKBACK 28 * 2 * 5 // making this a 5 minute average
+#define DISTANCE_AVG_LOOKBACK 28 * 2 * 3 // making this a 3 minute average
 
 // When significant changes occur in the sensor measurements, they are
 // published to MQTT. These definitions specify what is considered significant.
@@ -22,10 +22,10 @@
 #define HUMIDITY_SIGNIFICANT_CHANGE 2    // also to dampen flapping behavior.
 #define DISTANCE_SIGNIFICANT_CHANGE 3    // based on the sensor specification of 3mm resolution
 
-// The minimal interval at which to forcibly publish measurements to the MQTT broker.
+// The minimal interval in seconds at which to forcibly publish measurements to the
-// When significant changes occur in the measurements, then these will be published
+// MQTT broker. When significant changes occur in the measurements, then these will
-// to the MQTT broker at all times, independent from this interval.
+// be published to the MQTT broker at all times, independent from this interval.
-#define PUBLISH_INTERVAL 4000
+#define PUBLISH_INTERVAL 300
 
 #include <Arduino.h>
 #include "Data/Measurements.h"
@@ -50,39 +50,31 @@ typedef enum
 class DataController
 {
 public:
-    static DataController* Instance();
+    static DataController *Instance();
     void setup();
     void loop();
     void clearHistory();
     void setContainerHeight(int height);
     bool isConfigured();
-    static void handleMqttConnect(DoughMQTT* mqtt);
+    static void handleMqttConnect(DoughMQTT *mqtt);
     static void handleMqttMessage(String &key, String &value);
 
 private:
     DataController();
-    static DataController* _instance;
+    static DataController *_instance;
+    DoughUI *_ui;
+    DoughMQTT *_mqtt;
+    DoughSensors *_sensors;
     Measurements _temperatureMeasurements;
-    Measurement _temperatureLastPublished;
-    void _publishTemperature();
     Measurements _humidityMeasurements;
-    Measurement _humidityLastPublished;
-    void _publishHumidity();
     Measurements _distanceMeasurements;
-    Measurement _distanceLastPublished;
-    void _publishDistance();
     DoughLogger _logger;
-    DoughUI* _ui;
-    DoughSensors* _sensors;
-    DoughMQTT* _mqtt;
     unsigned long _lastSample = 0;
-    unsigned long _lastPublish = 0;
     DoughSampleType _sampleType = SAMPLE_TEMPERATURE;
     int _sampleCounter = 0;
     int _containerHeight;
     bool _containerHeightSet;
     void _sample();
-    void _publish();
 };
 
 #endif

src/Data/Measurement.cpp

@@ -15,3 +15,15 @@ Measurement Measurement::Value(int value)
     m.value = value;
     return m;
 }
+
+void Measurement::clear()
+{
+    ok = false;
+    value = 0;
+}
+
+void Measurement::copyTo(Measurement* target)
+{
+    target->ok = ok;
+    target->value = value;
+}

src/Data/Measurement.h

@@ -13,6 +13,8 @@ public:
     bool ok = false;
     static Measurement Failed();
     static Measurement Value(int value);
+    void clear();
+    void copyTo(Measurement *target);
 };
 
 #endif

src/Data/Measurements.cpp

@@ -1,22 +1,111 @@
 #include "Data/Measurements.h"
 #include "UI/DoughUI.h"
 
-Measurements::Measurements(unsigned int avgLookback)
+Measurements::Measurements(
+    const char *mqttKey,
+    Measurement (*measureFunc)(),
+    unsigned int storageSize,
+    unsigned int significantChange,
+    unsigned int minimumPublishTime)
 {
-    _storageSize = avgLookback;
+    _mqttKey = mqttKey;
+    _measureFunc = measureFunc;
+    _storageSize = storageSize;
+    _significantChange = significantChange;
+    _minimumPublishTime = minimumPublishTime;
+    _mqtt = DoughMQTT::Instance();
 
-    _storage = new Measurement*[avgLookback];
+    // Format the key to use for publishing the average (i.e. "<mqttKey>/average").
-    for (unsigned int i = 0; i < avgLookback; i++) {
+    auto lenAverageKey = strlen(mqttKey) + 8;      // +8 for the "/average" suffix
+    _mqttAverageKey = new char[lenAverageKey + 1]; // +1 for the ending \0
+    snprintf(_mqttAverageKey, lenAverageKey, "%s/average", _mqttKey);
+
+    // Initialize the storage for holding the measurements.
+    _storage = new Measurement *[storageSize];
+    for (unsigned int i = 0; i < storageSize; i++)
+    {
         _storage[i] = new Measurement;
     }
     clearHistory();
 }
 
-void Measurements::add(Measurement measurement)
+void Measurements::process()
 {
-    unsigned int index = _next();
+    auto m = _measureFunc();
-    _storage[index]->ok = measurement.ok;
+    _add(m);
-    _storage[index]->value = measurement.value;
+    if (_mustPublish())
+    {
+        _publish();
+    }
+}
+
+bool Measurements::_mustPublish()
+{
+    Measurement lastMeasurement = getLast();
+
+    // When the measurement failed, then there's no need to publish it.
+    if (lastMeasurement.ok == false)
+    {
+        return false;
+    }
+
+    // When no data was published before, then this is a great time to do so.
+    if (_lastPublished.ok == false)
+    {
+        return true;
+    }
+
+    // If the value did not change, only publish when the minimum publishing
+    // time has passed.
+    if (_lastPublished.value == lastMeasurement.value)
+    {
+        auto now = millis();
+        auto delta = now - _lastPublishedAt;
+        return _lastPublishedAt == 0 || delta >= (_minimumPublishTime * 1000);
+    }
+
+    // When there is a significant change in the sensor value, then publish.
+    if (abs(_lastPublished.value - lastMeasurement.value) >= _significantChange)
+    {
+        return true;
+    }
+
+    auto average = getAverage();
+
+    // When there is a significant change in the average value, then publish.
+    if (average.ok && abs(_lastPublishedAverage.value - average.value) >= _significantChange)
+    {
+        return true;
+    }
+
+    // When the value changed less than the significant change, but it reached
+    // the current average value, then publish it, since we might have reached
+    // a stable value.
+    if (average.ok && average.value == lastMeasurement.value)
+    {
+        return true;
+    }
+
+    // Well, we're out of options. No reason to publish the data right now.
+    return false;
+}
+
+void Measurements::_publish()
+{
+    auto average = getAverage();
+    auto last = getLast();
+
+    _mqtt->publish(_mqttKey, last);
+    _mqtt->publish(_mqttAverageKey, average);
+
+    _lastPublishedAt = millis();
+    average.copyTo(&_lastPublishedAverage);
+    last.copyTo(&_lastPublished);
+}
+
+void Measurements::_add(Measurement measurement)
+{
+    measurement.copyTo(_storage[_next()]);
 
     if (measurement.ok)
     {
@@ -28,17 +117,22 @@ void Measurements::add(Measurement measurement)
 unsigned int Measurements::_next()
 {
     _index++;
+
+    // Wrap around at the end of the circular buffer.
     if (_index == _storageSize)
     {
         _index = 0;
     }
+
+    // If the new position contains an ok value, update the running totals.
     if (_storage[_index]->ok)
     {
         _averageSum -= _storage[_index]->value;
         _averageCount--;
     }
-    _storage[_index]->ok = false;
+
-    _storage[_index]->value = 0;
+    _storage[_index]->clear();
+
     return _index;
 }
 
@@ -49,13 +143,9 @@ Measurement Measurements::getLast()
 
 Measurement Measurements::getAverage()
 {
-    Measurement result;
+    return _averageCount > 0
-    if (_averageCount > 0)
+               ? Measurement::Value(round(_averageSum / _averageCount))
-    {
+               : Measurement::Failed();
-        result.ok = true;
-        result.value = round(_averageSum / _averageCount);
-    }
-    return result;
 }
 
 void Measurements::clearHistory()
@@ -64,7 +154,6 @@ void Measurements::clearHistory()
     _averageSum = 0;
     for (unsigned int i = 0; i < _storageSize; i++)
     {
-        _storage[i]->ok = false;
+        _storage[i]->clear();
-        _storage[i]->value = 0;
     }
 }

src/Data/Measurements.h

@@ -3,26 +3,61 @@
 
 #include <Arduino.h>
 #include "Data/Measurement.h"
+#include "Network/DoughMQTT.h"
 
 /**
  * This class is used to store measurements for a sensor and to keep
  * track of running totals for handling average computations.
+ * It also provides functionality to decide when to publish measurements
+ * to MQTT (after significant changes occur or when the last publish
+ * was too long ago).
  */
 class Measurements
 {
 public:
-    Measurements(unsigned int avgLookback);
+    /**
-    void add(Measurement measurement);
+     * Create a new Measurements object.
+     * 
+     * @param measureFunc
+     *     Function that reads a sensor and returns a Measurement object.
+     * @param storageSize
+     *     Number of measurements to keep track of for computing an average.
+     * @param significantChange
+     *     Number that describes how much a measurement value needs to change,
+     *     before it is considered significant and must be published to MQTT.
+     * @param minimumPublishTime
+     *     The number of seconds after which to forcibly publish measurements
+     *     to MQTT, even when no significant changes to measurements were seen.
+     */
+    Measurements(
+        const char *mqttKey,
+        Measurement (*measureFunc)(),
+        unsigned int storageSize,
+        unsigned int significantChange,
+        unsigned int minimumPublishTime);
+    void process();
     Measurement getLast();
     Measurement getAverage();
     void clearHistory();
 
 private:
-    Measurement** _storage;
+    DoughMQTT *_mqtt;
+    const char *_mqttKey;
+    char *_mqttAverageKey;
+    Measurement (*_measureFunc)();
+    Measurement **_storage;
     unsigned int _storageSize;
+    unsigned int _significantChange;
+    unsigned int _minimumPublishTime;
     int _averageSum = 0;
     unsigned int _averageCount = 0;
     unsigned int _index = 0;
+    unsigned long _lastPublishedAt = 0;
+    Measurement _lastPublished;
+    Measurement _lastPublishedAverage;
+    bool _mustPublish();
+    void _publish();
+    void _add(Measurement measurement);
     unsigned int _next();
 };
 

src/Network/DoughMQTT.cpp

@@ -4,12 +4,9 @@
 // Constructor
 // ----------------------------------------------------------------------
 
-DoughMQTT* DoughMQTT::_instance = nullptr;
+DoughMQTT *DoughMQTT::_instance = nullptr;
 
-/**
+DoughMQTT *DoughMQTT::Instance()
- * Fetch the DoughMQTT singleton.
- */
-DoughMQTT* DoughMQTT::Instance()
 {
     if (DoughMQTT::_instance == nullptr)
     {
@@ -18,7 +15,7 @@ DoughMQTT* DoughMQTT::Instance()
     return DoughMQTT::_instance;
 }
 
-DoughMQTT::DoughMQTT() : _logger("MQTT") { }
+DoughMQTT::DoughMQTT() : _logger("MQTT") {}
 
 // ----------------------------------------------------------------------
 // Setup
@@ -26,7 +23,7 @@ DoughMQTT::DoughMQTT() : _logger("MQTT") { }
 
 void DoughMQTT::setup()
 {
-    DoughWiFi* network = DoughWiFi::Instance();
+    DoughWiFi *network = DoughWiFi::Instance();
 
 #ifdef MQTT_DEVICE_ID
     _mqttDeviceId = MQTT_DEVICE_ID;
@@ -88,7 +85,7 @@ void DoughMQTT::handleMessage(String &topic, String &payload)
 {
     DoughMQTT::Instance()->_logger.log("sSsS", "<<< ", topic, " = ", payload);
 
-    DoughMQTT* mqtt = DoughMQTT::Instance();
+    DoughMQTT *mqtt = DoughMQTT::Instance();
     if (mqtt->_onMessage != nullptr)
     {
         int pos = topic.lastIndexOf('/');
@@ -100,7 +97,7 @@ void DoughMQTT::handleMessage(String &topic, String &payload)
     }
 }
 
-void DoughMQTT::subscribe(const char* key)
+void DoughMQTT::subscribe(const char *key)
 {
     char topic[200];
     snprintf(topic, sizeof(topic) / sizeof(topic[0]), "%s/%s/%s", MQTT_TOPIC_PREFIX, _mqttDeviceId, key);
@@ -108,7 +105,7 @@ void DoughMQTT::subscribe(const char* key)
     _mqttClient.subscribe(topic);
 }
 
-void DoughMQTT::publish(const char* key, const char* payload)
+void DoughMQTT::publish(const char *key, const char *payload)
 {
     char topic[200];
     snprintf(topic, sizeof(topic) / sizeof(topic[0]), "%s/%s/%s", MQTT_TOPIC_PREFIX, _mqttDeviceId, key);
@@ -123,10 +120,14 @@ void DoughMQTT::publish(const char *key, int payload)
     publish(key, buf);
 }
 
-void DoughMQTT::publish(const char *key, Measurement measurement) {
+void DoughMQTT::publish(const char *key, Measurement measurement)
-    if (measurement.ok) {
+{
+    if (measurement.ok)
+    {
         publish(key, measurement.value);
-    } else {
+    }
+    else
+    {
         publish(key, "null");
     }
 }

src/Network/DoughMQTT.h

@@ -14,33 +14,33 @@
  */
 class DoughMQTT;
 
-typedef void (*DoughMQTTConnectHandler)(DoughMQTT* mqtt);
+typedef void (*DoughMQTTConnectHandler)(DoughMQTT *mqtt);
 typedef void (*DoughMQTTMessageHandler)(String &key, String &value);
 
 class DoughMQTT
 {
 public:
-    static DoughMQTT* Instance();
+    static DoughMQTT *Instance();
     void setup();
     void onConnect(DoughMQTTConnectHandler callback);
     void onMessage(DoughMQTTMessageHandler callback);
     bool isConnected();
     bool connect();
-    void subscribe(const char* key);
+    void subscribe(const char *key);
     void procesIncomingsMessages();
-    void publish(const char* key, const char* payload);
+    void publish(const char *key, const char *payload);
-    void publish(const char* key, int payload);
+    void publish(const char *key, int payload);
-    void publish(const char* key, Measurement measurement);
+    void publish(const char *key, Measurement measurement);
 
 private:
     DoughMQTT();
-    static DoughMQTT* _instance;
+    static DoughMQTT *_instance;
     MQTTClient _mqttClient;
     DoughLogger _logger;
     DoughMQTTConnectHandler _onConnect = nullptr;
     MQTTClientCallbackSimple _onMessage = nullptr;
     static void handleMessage(String &topic, String &payload);
-    char* _mqttDeviceId;
+    char *_mqttDeviceId;
 };
 
 #endif

src/Network/DoughWiFi.cpp

@@ -6,9 +6,6 @@
 
 DoughWiFi *DoughWiFi::_instance = nullptr;
 
-/**
- * Fetch the DoughWiFi singleton.
- */
 DoughWiFi *DoughWiFi::Instance()
 {
     if (DoughWiFi::_instance == nullptr)

src/Network/DoughWiFi.h

@@ -11,8 +11,8 @@
 class DoughWiFi
 {
 public:
-    static DoughWiFi* Instance();
+    static DoughWiFi *Instance();
-    char* getMacAddress();
+    char *getMacAddress();
     void setup();
     void loop();
     bool isConnected();
@@ -21,7 +21,7 @@ public:
 
 private:
     DoughWiFi();
-    static DoughWiFi* _instance;
+    static DoughWiFi *_instance;
     void _setMacAddress();
     char _macAddress[18]; // max MAC address length + 1
     DoughLogger _logger;

src/Sensors/DoughSensors.cpp

@@ -4,19 +4,19 @@
 // Constructor
 // ----------------------------------------------------------------------
 
-DoughSensors* DoughSensors::_instance = nullptr;
+DoughSensors *DoughSensors::_instance = nullptr;
 
-/**
+DoughSensors *DoughSensors::Instance()
- * Fetch the DoughSensors singleton.
+{
- */
+    if (DoughSensors::_instance == nullptr)
-DoughSensors* DoughSensors::Instance() {
+    {
-    if (DoughSensors::_instance == nullptr) {
         DoughSensors::_instance = new DoughSensors();
     }
     return DoughSensors::_instance;
 }
 
-DoughSensors::DoughSensors() : _logger("SENSORS") {
+DoughSensors::DoughSensors() : _logger("SENSORS")
+{
     _dht = new DHT(DHT11_DATA_PIN, DHT11);
     _hcsr04 = new HCSR04(HCSR04_TRIG_PIN, HCSR04_ECHO_PIN);
 }
@@ -25,7 +25,8 @@ DoughSensors::DoughSensors() : _logger("SENSORS") {
 // setup
 // ----------------------------------------------------------------------
 
-void DoughSensors::setup() {
+void DoughSensors::setup()
+{
     _dht->begin();
     _hcsr04->begin();
 }
@@ -34,12 +35,16 @@ void DoughSensors::setup() {
 // loop
 // ----------------------------------------------------------------------
 
-Measurement DoughSensors::readTemperature() {
+Measurement DoughSensors::readTemperature()
+{
     float t = _dht->readTemperature();
-    if (isnan(t)) {
+    if (isnan(t))
+    {
         _logger.log("s", "ERROR - Temperature measurement failed");
         return Measurement::Failed();
-    } else {
+    }
+    else
+    {
         _logger.log("sis", "Temperature = ", int(t), "°C ");
         _hcsr04->setTemperature(int(t));
         auto m = Measurement::Value(int(t));
@@ -47,25 +52,52 @@ Measurement DoughSensors::readTemperature() {
     }
 }
 
-Measurement DoughSensors::readHumidity() {
+Measurement DoughSensors::readHumidity()
+{
     int h = _dht->readHumidity();
-    if (h == 0) {
+    if (h == 0)
+    {
         _logger.log("s", "ERROR - Humidity measurement failed");
         return Measurement::Failed();
-    } else {
+    }
+    else
+    {
         _logger.log("sis", "Humidity = ", h, "%");
         _hcsr04->setHumidity(h);
         return Measurement::Value(h);
     }
 }
 
-Measurement DoughSensors::readDistance() {
+Measurement DoughSensors::readDistance()
+{
     int d = _hcsr04->readDistance();
-    if (d == -1) {
+    if (d == -1)
+    {
         _logger.log("s", "ERROR - Distance measurement failed");
         return Measurement::Failed();
-    } else {
+    }
+    else
+    {
         _logger.log("sis", "Distance = ", d, "mm");
         return Measurement::Value(d);
     }
 }
+
+// ----------------------------------------------------------------------
+// Function access to the sensor reading.
+// ----------------------------------------------------------------------
+
+Measurement readTemperature()
+{
+    return DoughSensors::Instance()->readTemperature();
+}
+
+Measurement readHumidity()
+{
+    return DoughSensors::Instance()->readHumidity();
+}
+
+Measurement readDistance()
+{
+    return DoughSensors::Instance()->readDistance();
+}

src/Sensors/DoughSensors.h

@@ -10,20 +10,25 @@
 /**
  * This class provides access to the sensors in the device.
  */
-class DoughSensors {
+class DoughSensors
-    public:
+{
-        static DoughSensors* Instance();
+public:
+    static DoughSensors *Instance();
     void setup();
     Measurement readTemperature();
     Measurement readHumidity();
     Measurement readDistance();
 
-    private:
+private:
     DoughSensors();
-        static DoughSensors* _instance;
+    static DoughSensors *_instance;
     DoughLogger _logger;
-        DHT* _dht;
+    DHT *_dht;
-        HCSR04* _hcsr04;
+    HCSR04 *_hcsr04;
 };
 
+Measurement readTemperature();
+Measurement readHumidity();
+Measurement readDistance();
+
 #endif

src/Sensors/HCSR04.cpp

@@ -1,22 +1,26 @@
 #include "Sensors/HCSR04.h"
 
-HCSR04::HCSR04(int triggerPin, int echoPin) {
+HCSR04::HCSR04(int triggerPin, int echoPin)
+{
     _triggerPin = triggerPin;
     _echoPin = echoPin;
     _temperature = HCSR04_INIT_TEMPERATURE;
     _humidity = HCSR04_INIT_HUMIDITY;
 }
 
-void HCSR04::begin() {
+void HCSR04::begin()
+{
     pinMode(_triggerPin, OUTPUT);
     pinMode(_echoPin, INPUT);
 }
 
-void HCSR04::setTemperature(int temperature) {
+void HCSR04::setTemperature(int temperature)
+{
     _temperature = temperature;
 }
 
-void HCSR04::setHumidity(int humidity) {
+void HCSR04::setHumidity(int humidity)
+{
     _humidity = humidity;
 }
 
@@ -25,11 +29,13 @@ void HCSR04::setHumidity(int humidity) {
  * When reading the distance fails, -1 is returned.
  * Otherwise the distance in mm.
  */
-int HCSR04::readDistance() {
+int HCSR04::readDistance()
+{
     _setSpeedOfSound();
     _setEchoTimeout();
     _takeSamples();
-    if (_haveEnoughSamples()) {
+    if (_haveEnoughSamples())
+    {
         _sortSamples();
         return _computeAverage();
     }
@@ -41,39 +47,47 @@ int HCSR04::readDistance() {
  * and relative humidity. I derived this formula from a YouTube
  * video about the HC-SR04: https://youtu.be/6F1B_N6LuKw?t=1548
  */
-void HCSR04::_setSpeedOfSound() {
+void HCSR04::_setSpeedOfSound()
+{
     _speedOfSound =
         0.3314 +
         (0.000606 * _temperature) +
         (0.0000124 * _humidity);
 }
 
-void HCSR04::_setEchoTimeout() {
+void HCSR04::_setEchoTimeout()
+{
     _echoTimeout = HCSR04_MAX_MM * 2 / _speedOfSound;
 }
 
-void HCSR04::_takeSamples() {
+void HCSR04::_takeSamples()
+{
     _successfulSamples = 0;
-    for (int i = 0; i<HCSR04_SAMPLES_TAKE; i++) {
+    for (int i = 0; i < HCSR04_SAMPLES_TAKE; i++)
+    {
         // Because I notice some repeating patterns in timings when doing
         // a tight loop here, I add some random waits to get a better spread
         // of sample values.
-        if (i > 0) {
+        if (i > 0)
+        {
             delay(HCSR04_SAMPLE_WAIT + random(HCSR04_SAMPLE_WAIT_SPREAD));
         }
         int distance = _takeSample();
-        if (distance != -1) {
+        if (distance != -1)
+        {
             _samples[i] = distance;
             _successfulSamples++;
         }
     }
 }
 
-bool HCSR04::_haveEnoughSamples() {
+bool HCSR04::_haveEnoughSamples()
+{
     return _successfulSamples >= HCSR04_SAMPLES_USE;
 }
 
-int HCSR04::_takeSample() {
+int HCSR04::_takeSample()
+{
     // Send 10μs trigger to ask sensor for a measurement.
     digitalWrite(HCSR04_TRIG_PIN, LOW);
     delayMicroseconds(2);
@@ -86,20 +100,27 @@ int HCSR04::_takeSample() {
 
     // Compute the distance, based on the echo signal length.
     double distance = durationMicroSec / 2.0 * _speedOfSound;
-    if (distance < HCSR04_MIN_MM || distance >= HCSR04_MAX_MM) {
+    if (distance < HCSR04_MIN_MM || distance >= HCSR04_MAX_MM)
+    {
         return -1;
-    } else {
+    }
+    else
+    {
         return distance;
     }
 }
 
-void HCSR04::_sortSamples() {
+void HCSR04::_sortSamples()
+{
     int holder, x, y;
-    for(x = 0; x < _successfulSamples; x++) {
+    for (x = 0; x < _successfulSamples; x++)
-       for(y = 0; y < _successfulSamples-1; y++) {
+    {
-           if(_samples[y] > _samples[y+1]) {
+        for (y = 0; y < _successfulSamples - 1; y++)
-               holder = _samples[y+1];
+        {
-               _samples[y+1] = _samples[y];
+            if (_samples[y] > _samples[y + 1])
+            {
+                holder = _samples[y + 1];
+                _samples[y + 1] = _samples[y];
                 _samples[y] = holder;
             }
         }
@@ -112,11 +133,13 @@ void HCSR04::_sortSamples() {
  * When not enough samples were collected in the previous steps, then
  * NAN is returned.
  */
-int HCSR04::_computeAverage() {
+int HCSR04::_computeAverage()
+{
     float sum = 0;
     int offset = (_successfulSamples - HCSR04_SAMPLES_USE) / 2;
-    for (int i = 0; i<HCSR04_SAMPLES_USE; i++) {
+    for (int i = 0; i < HCSR04_SAMPLES_USE; i++)
-        sum += _samples[i+offset];
+    {
+        sum += _samples[i + offset];
     }
 
     return round(sum / HCSR04_SAMPLES_USE);

src/Sensors/HCSR04.h

@@ -31,15 +31,16 @@
 /**
  * This class is used to get a distance reading from an HCSR04 sensor.
  */
-class HCSR04 {
+class HCSR04
-    public:
+{
+public:
     HCSR04(int triggerPin, int echoPin);
     void begin();
     void setTemperature(int temperature);
     void setHumidity(int humidity);
     int readDistance();
 
-    private:
+private:
     int _triggerPin;
     int _echoPin;
     int _humidity;

src/UI/DoughLogger.cpp

@@ -5,7 +5,7 @@ DoughLogger::DoughLogger(const char *section)
     _section = section;
 }
 
-void DoughLogger::log(const char* fmt, ...)
+void DoughLogger::log(const char *fmt, ...)
 {
     char buf[LOGGER_PREFIX_BUFLEN];
     snprintf(buf, sizeof(buf) / sizeof(buf[0]), LOGGER_PREFIX_FORMAT, _section);

src/UI/DoughLogger.h

@@ -19,7 +19,7 @@ public:
     void log(const char *fmt, ...);
 
 private:
-    const char* _section;
+    const char *_section;
 };
 
 #endif