Rename constants for topics

Add intermediate class "SensorNode" Add helper function to fix value ranges Add helper function to calculate absolute humidity Derive DHT22/BME280/DS18B20 from SensorNode Add absolute humidity for DHT22/BME280 to reported values
luebbe · Sep 21, 2019 · 93a2c16 · 93a2c16
1 parent f91fbf3
commit 93a2c16
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Showing 10 changed files with 172 additions and 66 deletions.
diff --git a/src/AdcNode.cpp b/src/AdcNode.cpp
@@ -71,8 +71,8 @@ void AdcNode::send()
   }
   else
   {
-    setProperty(cVoltage).send(String(_voltage));
-    setProperty(cBatteryLevel).send(String(_batteryLevel));
+    setProperty(cVoltageTopic).send(String(_voltage));
+    setProperty(cBatteryLevelTopic).send(String(_batteryLevel));
     Homie.getLogger() << cIndent << "Voltage: " << _voltage << "V" << endl;
     Homie.getLogger() << cIndent << "Battery level: " << _batteryLevel << "%" << endl;
   }
@@ -113,17 +113,17 @@ void AdcNode::beforeHomieSetup()
 void AdcNode::onReadyToOperate()
 {
   // Will be called after MQTT_CONNECT
-  setProperty(cVoltageUnit).send("V");
-  setProperty(cBatteryLevelUnit).send("%");
+  setProperty(cVoltageUnitTopic).send("V");
+  setProperty(cBatteryLevelUnitTopic).send("%");
 };
 
 void AdcNode::setup()
 {
   // Will be called from Homie.setup()
-  advertise(cVoltage);
-  advertise(cVoltageUnit);
-  advertise(cBatteryLevel);
-  advertise(cBatteryLevelUnit);
+  advertise(cVoltageTopic);
+  advertise(cVoltageUnitTopic);
+  advertise(cBatteryLevelTopic);
+  advertise(cBatteryLevelUnitTopic);
 
   printCaption();
   Homie.getLogger() << cIndent << "Send interval: " << _sendInterval / 1000 << " s" << endl;

diff --git a/src/BME280Node.cpp b/src/BME280Node.cpp
@@ -18,7 +18,7 @@ BME280Node::BME280Node(const char *name,
                        const Adafruit_BME280::sensor_sampling tempSampling,
                        const Adafruit_BME280::sensor_sampling pressSampling,
                        const Adafruit_BME280::sensor_sampling humSampling,
-                       const Adafruit_BME280::sensor_filter filter) : HomieNode(name, "BME280", "sensor"),
+                       const Adafruit_BME280::sensor_filter filter) : SensorNode(name, "BME280"),
                                                                       _i2cAddress(i2cAddress),
                                                                       _lastMeasurement(0),
                                                                       _tempSampling(tempSampling),
@@ -31,7 +31,7 @@ BME280Node::BME280Node(const char *name,
 
 void BME280Node::printCaption()
 {
-  Homie.getLogger() << cCaption << endl;
+  Homie.getLogger() << cCaption << " i2c[" << _i2cAddress << "]:" << endl;
 }
 
 void BME280Node::loop()
@@ -47,22 +47,30 @@ void BME280Node::loop()
       humidity = bme.readHumidity();
       pressure = bme.readPressure() / 100;
 
+      fixRange(&temperature, cMinTemp, cMaxTemp);
+      fixRange(&humidity, cMinHumid, cMaxHumid);
+      fixRange(&pressure, cMinPress, cMaxPress);
+
       printCaption();
 
+      float absHumidity = computeAbsoluteHumidity(temperature, humidity);
+
       Homie.getLogger() << cIndent << "Temperature: " << temperature << " °C" << endl;
       temperature += temperatureOffsetSetting.get();
       Homie.getLogger() << cIndent << "Temperature (after offset): " << temperature << " °C" << endl;
       Homie.getLogger() << cIndent << "Humidity: " << humidity << " %" << endl;
       Homie.getLogger() << cIndent << "Pressure: " << pressure << " hPa" << endl;
+      Homie.getLogger() << cIndent << "Abs humidity: " << absHumidity << " g/m³" << endl;
 
-      setProperty(cStatus).send("ok");
-      setProperty(cTemperature).send(String(temperature));
-      setProperty(cHumidity).send(String(humidity));
-      setProperty(cPressure).send(String(pressure));
+      setProperty(cStatusTopic).send("ok");
+      setProperty(cTemperatureTopic).send(String(temperature));
+      setProperty(cHumidityTopic).send(String(humidity));
+      setProperty(cPressureTopic).send(String(pressure));
+      setProperty(cAbsHumidityTopic).send(String(absHumidity));
     }
     else
     {
-      setProperty(cStatus).send("error");
+      setProperty(cStatusTopic).send("error");
     }
     _lastMeasurement = millis();
   }
@@ -77,20 +85,23 @@ void BME280Node::beforeHomieSetup()
 
 void BME280Node::onReadyToOperate()
 {
-  setProperty(cTemperatureUnit).send("°C");
-  setProperty(cHumidityUnit).send("%");
-  setProperty(cPressureUnit).send("hPa");
+  setProperty(cTemperatureUnitTopic).send("°C");
+  setProperty(cHumidityUnitTopic).send("%");
+  setProperty(cPressureUnitTopic).send("hPa");
+  setProperty(cAbsHumidityUnitTopic).send("g/m³");
 };
 
 void BME280Node::setup()
 {
-  advertise(cStatus);
-  advertise(cTemperature);
-  advertise(cTemperatureUnit);
-  advertise(cHumidity);
-  advertise(cHumidityUnit);
-  advertise(cPressure);
-  advertise(cPressureUnit);
+  advertise(cStatusTopic);
+  advertise(cTemperatureTopic);
+  advertise(cTemperatureUnitTopic);
+  advertise(cHumidityTopic);
+  advertise(cHumidityUnitTopic);
+  advertise(cPressureTopic);
+  advertise(cPressureUnitTopic);
+  advertise(cAbsHumidityTopic);
+  advertise(cAbsHumidityUnitTopic);
 
   if (bme.begin(_i2cAddress))
   {

diff --git a/src/BME280Node.hpp b/src/BME280Node.hpp
@@ -14,15 +14,18 @@
 #include <SPI.h>
 #include <Wire.h>
 
-#include <HomieNode.hpp>
+#include "SensorNode.hpp"
 #include "constants.hpp"
 
-class BME280Node : public HomieNode
+class BME280Node : public SensorNode
 {
 private:
+  const float cMinTemp = -40.0;
+  const float cMaxTemp = 85.0;
+  const float cMinPress = 300.0;
+  const float cMaxPress = 1100.0;
   // suggested rate is 1/60Hz (1m)
   static const int MIN_INTERVAL = 60; // in seconds
-  static const int MEASUREMENT_INTERVAL = 300;
   const char *cCaption = "• BME280 sensor:";
   const char *cIndent = "  ◦ ";
 

diff --git a/src/DHT22Node.cpp b/src/DHT22Node.cpp
@@ -11,7 +11,7 @@
 #define DHTTYPE DHT22
 
 DHT22Node::DHT22Node(const char *name, const int sensorPin, const int measurementInterval)
-    : HomieNode(name, "DHT22", "sensor"),
+    : SensorNode(name, "DHT22"),
       _sensorPin(sensorPin),
       _measurementInterval(measurementInterval),
       _lastMeasurement(0)
@@ -37,21 +37,28 @@ void DHT22Node::loop()
       temperature = dht->readTemperature();
       humidity = dht->readHumidity();
 
+      fixRange(&temperature, cMinTemp, cMaxTemp);
+      fixRange(&humidity, cMinHumid, cMaxHumid);
+
       printCaption();
 
       if (isnan(temperature) || isnan(humidity))
       {
         Homie.getLogger() << cIndent << "Error reading from Sensor" << endl;
-        setProperty(cStatus).send("error");
+        setProperty(cStatusTopic).send("error");
       }
       else
       {
+        float absHumidity = computeAbsoluteHumidity(temperature, humidity);
+
         Homie.getLogger() << cIndent << "Temperature: " << temperature << " °C" << endl;
         Homie.getLogger() << cIndent << "Humidity: " << humidity << " %" << endl;
+        Homie.getLogger() << cIndent << "Abs humidity: " << absHumidity << " g/m³" << endl;
 
-        setProperty(cStatus).send("ok");
-        setProperty(cTemperature).send(String(temperature));
-        setProperty(cHumidity).send(String(humidity));
+        setProperty(cStatusTopic).send("ok");
+        setProperty(cTemperatureTopic).send(String(temperature));
+        setProperty(cHumidityTopic).send(String(humidity));
+        setProperty(cAbsHumidityTopic).send(String(absHumidity));
       }
       _lastMeasurement = millis();
     }
@@ -60,17 +67,20 @@ void DHT22Node::loop()
 
 void DHT22Node::onReadyToOperate()
 {
-  setProperty(cTemperatureUnit).send("°C");
-  setProperty(cHumidityUnit).send("%");
+  setProperty(cTemperatureUnitTopic).send("°C");
+  setProperty(cHumidityUnitTopic).send("%");
+  setProperty(cAbsHumidityUnitTopic).send("g/m³");
 };
 
 void DHT22Node::setup()
 {
-  advertise(cStatus);
-  advertise(cTemperature);
-  advertise(cTemperatureUnit);
-  advertise(cHumidity);
-  advertise(cHumidityUnit);
+  advertise(cStatusTopic);
+  advertise(cTemperatureTopic);
+  advertise(cTemperatureUnitTopic);
+  advertise(cHumidityTopic);
+  advertise(cHumidityUnitTopic);
+  advertise(cAbsHumidityTopic);
+  advertise(cAbsHumidityUnitTopic);
 
   printCaption();
   Homie.getLogger() << cIndent << "Reading interval: " << _measurementInterval << " s" << endl;

diff --git a/src/DHT22Node.hpp b/src/DHT22Node.hpp
@@ -11,15 +11,18 @@
 #include <Adafruit_Sensor.h>
 #include <DHT_U.h>
 
-#include <Homie.hpp>
+#include "SensorNode.hpp"
 #include "constants.hpp"
 
 #define DEFAULTPIN -1
 
-class DHT22Node : public HomieNode
+class DHT22Node : public SensorNode
 {
 private:
-  static const int MEASUREMENT_INTERVAL = 300;
+  const float cMinTemp = -40.0;
+  const float cMaxTemp = 125.0;
+  const float cMinHumid = 0.0;
+  const float cMaxHumid = 100.0;
   const char *cCaption = "• DHT22 sensor";
   const char *cIndent = "  ◦ ";
 

diff --git a/src/DS18B20Node.cpp b/src/DS18B20Node.cpp
@@ -9,7 +9,7 @@
 #include "DS18B20Node.hpp"
 
 DS18B20Node::DS18B20Node(const char *name, const int sensorPin, const int measurementInterval)
-    : HomieNode(name, "DS18N20", "sensor"),
+    : SensorNode(name, "DS18N20"),
       _sensorPin(sensorPin),
       _measurementInterval(measurementInterval),
       _lastMeasurement(0)
@@ -34,17 +34,19 @@ void DS18B20Node::loop()
     {
       dallasTemp->requestTemperatures();
       temperature = dallasTemp->getTempCByIndex(0);
+      fixRange(&temperature, cMinTemp, cMaxTemp);
+
       printCaption();
       if (DEVICE_DISCONNECTED_C == temperature)
       {
         Homie.getLogger() << cIndent << "Error reading from Sensor" << endl;
-        setProperty(cStatus).send("error");
+        setProperty(cStatusTopic).send("error");
       }
       else
       {
         Homie.getLogger() << cIndent << "Temperature: " << temperature << " °C" << endl;
-        setProperty(cStatus).send("ok");
-        setProperty(cTemperature).send(String(temperature));
+        setProperty(cStatusTopic).send("ok");
+        setProperty(cTemperatureTopic).send(String(temperature));
       }
       _lastMeasurement = millis();
     }
@@ -53,14 +55,14 @@ void DS18B20Node::loop()
 
 void DS18B20Node::onReadyToOperate()
 {
-  setProperty(cTemperatureUnit).send("°C");
+  setProperty(cTemperatureUnitTopic).send("°C");
 };
 
 void DS18B20Node::setup()
 {
-  advertise(cStatus);
-  advertise(cTemperature);
-  advertise(cTemperatureUnit);
+  advertise(cStatusTopic);
+  advertise(cTemperatureTopic);
+  advertise(cTemperatureUnitTopic);
 
   printCaption();
   Homie.getLogger() << cIndent << "Reading interval: " << _measurementInterval << " s" << endl;

diff --git a/src/DS18B20Node.hpp b/src/DS18B20Node.hpp
@@ -11,14 +11,15 @@
 #include <OneWire.h>
 #include <DallasTemperature.h>
 
-#include <Homie.hpp>
+#include "SensorNode.hpp"
 #include "constants.hpp"
 
 #define DEFAULTPIN -1
 
-class DS18B20Node : public HomieNode {
+class DS18B20Node : public SensorNode {
 private:
-  static const int MEASUREMENT_INTERVAL = 300;
+  const float cMinTemp = -55.0;
+  const float cMaxTemp = 125.0;
   const char *cCaption = "• DS18B20 sensor";
   const char *cIndent = "  ◦ ";
 

diff --git a/src/SensorNode.cpp b/src/SensorNode.cpp
@@ -0,0 +1,48 @@
+/*
+ * SensorNode.hpp
+ * Homie Node for genric sensors.
+ * Provides a limit method for measurement values
+ *
+ * Version: 1.0
+ * Author: Lübbe Onken (http://github.com/luebbe)
+ */
+
+#include "SensorNode.hpp"
+
+SensorNode::SensorNode(const char *name, const char *type)
+    : HomieNode(name, type, "sensor")
+{
+}
+
+float SensorNode::computeAbsoluteHumidity(float temperature, float percentHumidity) {
+  // Calculate the absolute humidity in g/m³
+  // https://carnotcycle.wordpress.com/2012/08/04/how-to-convert-relative-humidity-to-absolute-humidity/
+
+  float absHumidity;
+  float absTemperature;
+  absTemperature = temperature + 273.15;
+
+  absHumidity = 6.112;
+  absHumidity *= exp((17.67 * temperature) / (243.5 + temperature));
+  absHumidity *= percentHumidity;
+  absHumidity *= 2.1674;
+  absHumidity /= absTemperature;
+
+  return absHumidity;
+}
+
+void SensorNode::fixRange(float *value, float min, float max)
+{
+  if (isnan(*value))
+  {
+    return;
+  }
+  else if (*value < min)
+  {
+    *value = min;
+  }
+  else if (*value > max)
+  {
+    *value = max;
+  };
+}
diff --git a/src/SensorNode.hpp b/src/SensorNode.hpp
@@ -0,0 +1,26 @@
+/*
+ * SensorNode.hpp
+ * Homie Node for genric sensors.
+ * Provides a limit method for measurement values
+ *
+ * Version: 1.0
+ * Author: Lübbe Onken (http://github.com/luebbe)
+ */
+
+#pragma once
+
+#include <Homie.hpp>
+
+class SensorNode : public HomieNode
+{
+protected:
+  const float cMinHumid = 0.0;
+  const float cMaxHumid = 100.0;
+  static const int MEASUREMENT_INTERVAL = 300;
+
+  float computeAbsoluteHumidity(float temperature, float percentHumidity);
+  void fixRange(float *value, float min, float max);
+
+public:
+  SensorNode(const char *name, const char *type);
+};