Creates some "default" configurations for gas sensor.

This can be a little difficult to set up, so cribbed the configuration setups from the sampleapps since they (obviously) were intended to work.

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

@@ -5,7 +5,7 @@
  * Organisation: diozero
  * Project: diozero - Core
  * Filename: BME68x.java
- * 
+ *
  * This file is part of the diozero project. More information about this project
  * can be found at https://www.diozero.com/.
  * %%
@@ -17,10 +17,10 @@
  * 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
@@ -39,13 +39,20 @@
 import com.diozero.util.BitManipulation;
 import com.diozero.util.SleepUtil;
 
-/*-
- *
- * https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bme680-ds001.pdf
- * https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bme688-ds000.pdf
- * https://github.com/BoschSensortec/BME68x-Sensor-API
- * https://github.com/pimoroni/bme680-python
- * https://github.com/knobtviker/bme680
+/**
+ * An environmental sensor: measures temperature, pressure, humity, and a "gas" sensor for general air quality. The
+ * actual values <i>may not</i> be entirely accurate for your environment, so may need minor adjustments: the typcal
+ * offset that needs to be applied witll be to the temperature (about 5 degrees high).
+ * <p>
+ * <b>NOTEL</b> once activated, it will take about 30 seconds for readings to become more precise.
+ * </p>
+ * <ul>
+ * <li>https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bme680-ds001.pdf</li>
+ * <li>https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bme688-ds000.pdf</li>
+ * <li>https://github.com/BoschSensortec/BME68x-Sensor-API</li>
+ * <li>https://github.com/pimoroni/bme680-python</li>
+ * <li>https://github.com/knobtviker/bme680</li>
+ * </ul>
  */
 public class BME68x implements BarometerInterface, ThermometerInterface, HygrometerInterface {
  // Chip vendor for the BME680
@@ -552,7 +559,7 @@ 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 +577,7 @@ 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
@@ -2012,4 +2019,53 @@ public String toString() {
  + ", heaterResistance=" + heaterResistance + ", gasWaitMs=" + gasWaitMs + "]";
  }
  }
+
+ /**
+ * Attempts to set reasonable defaults for the device since it's not that easy to configure.
+ *
+ * @return the determined operating mode for use with {@link #getSensorData(OperatingMode)}
+ */
+ public OperatingMode calculateDefaultConfiguration() {
+ // if it's the 688, use parallel mode
+ if (getVariantId() == BME68x.VARIANT_ID_BM688) {
+ Logger.debug("Using PARALLEL mode");
+ setConfiguration(OversamplingMultiplier.X2, OversamplingMultiplier.X2, OversamplingMultiplier.X2,
+ IirFilterCoefficient.NONE, StandbyDuration.NONE);
+ OperatingMode targetOperatingMode = OperatingMode.PARALLEL;
+
+ // Calculate TPHG measure duration and convert to milliseconds
+ int measureDurationMs = calculateMeasureDuration(targetOperatingMode) / 1000;
+ Logger.debug("measureDurationMs: {}", measureDurationMs);
+
+ // Assume that 150ms is the required heater duration.
+ // https://github.com/BoschSensortec/BME68x-Sensor-API/blob/master/examples/parallel_mode/parallel_mode.c#L78
+ // p39: Measurement duration = gas_wait_X * (gas_wait_shared + TTPHG_duration)
+ int heaterDurationMs = 150;
+ int gasWaitSharedMs = heaterDurationMs - measureDurationMs;
+ Logger.debug("gasWaitSharedMs: {}", gasWaitSharedMs);
+
+ HeaterConfig heaterConfig = new HeaterConfig(true, //
+ // Heater temperature in degree Celsius
+ new int[] { 320, 100, 100, 100, 200, 200, 200, 320, 320, 320 },
+ // Multiplier to the shared heater duration
+ new int[] { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 },
+ gasWaitSharedMs);
+ setHeaterConfiguration(targetOperatingMode, heaterConfig);
+ return targetOperatingMode;
+ }
+ // otherwise force mode
+ setDefaultConfiguration();
+ return OperatingMode.FORCED;
+ }
+
+ /**
+ * Sets a reasonable default for FORCED mode operation.
+ */
+ public void setDefaultConfiguration() {
+ Logger.debug("Using FORCED mode");
+ setConfiguration(OversamplingMultiplier.X2, OversamplingMultiplier.X2, OversamplingMultiplier.X2,
+ IirFilterCoefficient._3, StandbyDuration.NONE);
+
+ setHeaterConfiguration(OperatingMode.FORCED, new HeaterConfig(true, 320, 150));
+ }
 }

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

@@ -5,7 +5,7 @@
  * Organisation: diozero
  * Project: diozero - Sample applications
  * Filename: BME68xTest.java
- * 
+ *
  * This file is part of the diozero project. More information about this project
  * can be found at https://www.diozero.com/.
  * %%
@@ -17,10 +17,10 @@
  * 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
@@ -88,9 +88,13 @@ public static void main(String[] args) {
 
  if (bme68x.getVariantId() == BME68x.VARIANT_ID_BM688) {
  parallelModeTest(bme68x);
+ bme68x.softReset();
+
+ // should be identical to above
+ defaultConfigTest(bme68x);
+ bme68x.softReset();
  }
 
- bme68x.softReset();
 
  iaqTest(bme68x);
  } finally {
@@ -169,6 +173,15 @@ private static void parallelModeTest(BME68x bme68x) {
 
  System.out.println("heater_duration_ms: " + heater_duration_ms);
 
+ runParallelModeTest(bme68x, heater_duration_ms, target_operating_mode);
+ }
+
+ private static void defaultConfigTest(BME68x bme68x) {
+ OperatingMode mode = bme68x.calculateDefaultConfiguration();
+ runParallelModeTest(bme68x, 150, mode);
+ }
+
+ private static void runParallelModeTest(BME68x bme68x, int heater_duration_ms, OperatingMode target_operating_mode) {
  int last_gas_meas_idx = -1;
  long last_gas_meas_ms = System.currentTimeMillis();
  for (int i = 0; i < 100; i++) {