Further abstraction since interfaces can have static methods.

diozero-core/src/main/java/com/diozero/devices/AirQualitySensorInterface.java

@@ -0,0 +1,84 @@
+package com.diozero.devices;
+/*-
+ * #%L
+ * Organisation: diozero
+ * Project: diozero - Core
+ * Filename: AirQualitySensorInterface.java
+ *
+ * This file is part of the diozero project. More information about this project
+ * can be found at https://www.diozero.com/.
+ * %%
+ * Copyright (C) 2016 - 2024 diozero
+ * %%
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ * #L%
+ */
+
+/**
+ * An air-quality sensor uses relative humidity and a "resistance" value to measure air quaility.
+ */
+public interface AirQualitySensorInterface extends HygrometerInterface {
+ /**
+ * "Standard" humidity baseline typically used for indoor air-quality.
+ */
+ float STANDARD_INDOOR_HUMIDITY = 40f;
+
+ float getGasResistance();
+
+ /**
+ * Calculates the indoor air quality as a percentage based on a baseline reading. Based off of Pimoroni's
+ * <a href="https://github.com/pimoroni/bme680-python/blob/main/examples/indoor-air-quality.py">indoor-air-quality.py</a>
+ * <p>
+ * Under non-calibrated, general usage, it is recommended that the sensor "warm up" in the current mode for at least
+ * 30 minutes before taking readings. After that time, any kind of statistical baseline (e.g. average) for the gas
+ * and humidity readings can be used to get an indication of general air-quality.
+ * </p>
+ *
+ * @param gasReading current reading
+ * @param gasBaseline the "baseline" to score off of
+ * @param humidityReading current reading
+ * @param humidityBaseline the "baseline" to score off of
+ * @param humidityWeighting weighting applied to scoring (a good default is 0.25f)
+ */
+ static float airQuality(float gasReading, float gasBaseline, float humidityReading, float humidityBaseline,
+ float humidityWeighting) {
+ float gasOffset = gasBaseline - gasReading;
+ float humidityOffset = humidityReading - humidityBaseline;
+
+ float humidityScore;
+ if (humidityOffset > 0) {
+ humidityScore = (100 - humidityBaseline - humidityOffset) / (100 - humidityBaseline) * (humidityWeighting * 100);
+ }
+ else {
+ humidityScore = (humidityBaseline + humidityOffset) / humidityBaseline * (humidityWeighting * 100);
+ }
+
+ float gasScore;
+ if (gasOffset > 0) {
+ gasScore = (gasReading / gasBaseline) * (100 - (humidityWeighting * 100));
+ }
+ else {
+ gasScore = 100 - (humidityWeighting * 100);
+ }
+
+ // Calculate air_quality_score.
+ return humidityScore + gasScore;
+ }
+
+}

diozero-core/src/main/java/com/diozero/devices/BME68x.java

@@ -47,7 +47,7 @@
  * https://github.com/pimoroni/bme680-python
  * https://github.com/knobtviker/bme680
  */
-public class BME68x implements BarometerInterface, ThermometerInterface, HygrometerInterface {
+public class BME68x implements BarometerInterface, ThermometerInterface, AirQualitySensorInterface {
  // Chip vendor for the BME680
  private static final String CHIP_VENDOR = "Bosch";
  // Chip name for the BME680
@@ -552,7 +552,7 @@ public BME68x(final I2CDeviceInterface device) {
  * @param controller I2C bus the sensor is connected to.
  * @param address I2C address of the sensor.
  * @param humidityOversampling Humidity oversampling.
- * @param termperatureOversampling Temperature oversampling.
+ * @param temperatureOversampling Temperature oversampling.
  * @param pressureOversampling Pressure oversampling.
  * @param filter Infinite Impulse Response (IIR) filter.
  * @param standbyDuration Standby time between sequential mode
@@ -570,7 +570,7 @@ public BME68x(final int controller, final int address, OversamplingMultiplier hu
  *
  * @param device I2C device.
  * @param humidityOversampling Humidity oversampling.
- * @param termperatureOversampling Temperature oversampling.
+ * @param temperatureOversampling Temperature oversampling.
  * @param pressureOversampling Pressure oversampling.
  * @param filter Infinite Impulse Response (IIR) filter.
  * @param standbyDuration Standby time between sequential mode
@@ -910,6 +910,7 @@ public float getRelativeHumidity() {
  return getSensorData()[0].getHumidity();
  }
 
+ @Override
  public float getGasResistance() {
  return getSensorData()[0].getGasResistance();
  }
@@ -2013,43 +2014,4 @@ public String toString() {
  }
  }
 
- /**
- * Calculates the indoor air quality as a percentage based on a baseline reading. Based off of Pimoroni's
- * <a href="https://github.com/pimoroni/bme680-python/blob/main/examples/indoor-air-quality.py">indoor-air-quality.py</a>
- * <p>
- * Under non-calibrated, general usage, it is recommended that the sensor "warm up" in the current mode for at least
- * 30 minutes before taking readings. After that time, any kind of statistical baseline (e.g. average) for the gas
- * and humidity readings can be used to get an indication of general air-quality.
- * </p>
- *
- * @param gasReading current reading
- * @param gasBaseline the "baseline" to score off of
- * @param humidityReading current reading
- * @param humidityBaseline the "baseline" to score off of
- * @param humidityWeighting weighting applied to scoring (a good default is 0.25f)
- */
- public static float airQuality(float gasReading, float gasBaseline, float humidityReading, float humidityBaseline,
- float humidityWeighting) {
- float gasOffset = gasBaseline - gasReading;
- float humidityOffset = humidityReading - humidityBaseline;
-
- float humidityScore;
- if (humidityOffset > 0) {
- humidityScore = (100 - humidityBaseline - humidityOffset) / (100 - humidityBaseline) * (humidityWeighting * 100);
- }
- else {
- humidityScore = (humidityBaseline + humidityOffset) / humidityBaseline * (humidityWeighting * 100);
- }
-
- float gasScore;
- if (gasOffset > 0) {
- gasScore = (gasReading / gasBaseline) * (100 - (humidityWeighting * 100));
- }
- else {
- gasScore = 100 - (humidityWeighting * 100);
- }
-
- // Calculate air_quality_score.
- return humidityScore + gasScore;
- }
 }

diozero-sampleapps/src/main/java/com/diozero/sampleapps/BME68xTest.java

@@ -34,6 +34,7 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import com.diozero.devices.AirQualitySensorInterface;
 import com.diozero.devices.BME68x;
 import com.diozero.devices.BME68x.Data;
 import com.diozero.devices.BME68x.HeaterConfig;
@@ -277,7 +278,7 @@ private static void iaqTest(BME68x bme68x) {
  float hum = data[0].getHumidity();
 
  // Calculate air_quality_score.
- float air_quality_score = BME68x.airQuality(gas, gas_baseline, hum, hum_baseline, hum_weighting);
+ float air_quality_score = AirQualitySensorInterface.airQuality(gas, gas_baseline, hum, hum_baseline, hum_weighting);
  System.out.format("Gas: %,.2f Ohms, humidity: %,.2f %%RH, air quality: %,.2f%n", gas, hum, air_quality_score);
 
  SleepUtil.sleepSeconds(1);