[pwm] Initial Contribution

CODEOWNERS

@@ -8,6 +8,7 @@
 /bundles/org.openhab.automation.groovyscripting/ @wborn
 /bundles/org.openhab.automation.jythonscripting/ @openhab/add-ons-maintainers
 /bundles/org.openhab.automation.pidcontroller/ @fwolter
+/bundles/org.openhab.automation.pwm/ @fwolter
 /bundles/org.openhab.binding.adorne/ @theiding
 /bundles/org.openhab.binding.airquality/ @kubawolanin
 /bundles/org.openhab.binding.airvisualnode/ @3cky

bom/openhab-addons/pom.xml

@@ -31,6 +31,11 @@
       <artifactId>org.openhab.automation.pidcontroller</artifactId>
       <version>${project.version}</version>
     </dependency>
+    <dependency>
+      <groupId>org.openhab.addons.bundles</groupId>
+      <artifactId>org.openhab.automation.pwm</artifactId>
+      <version>${project.version}</version>
+    </dependency>
     <dependency>
       <groupId>org.openhab.addons.bundles</groupId>
       <artifactId>org.openhab.binding.adorne</artifactId>

bundles/org.openhab.automation.pwm/NOTICE

@@ -0,0 +1,13 @@
+This content is produced and maintained by the openHAB project.
+
+* Project home: https://www.openhab.org
+
+== Declared Project Licenses
+
+This program and the accompanying materials are made available under the terms
+of the Eclipse Public License 2.0 which is available at
+https://www.eclipse.org/legal/epl-2.0/.
+
+== Source Code
+
+https://github.com/openhab/openhab-addons

bundles/org.openhab.automation.pwm/README.md

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+# Pulse Width Modulation (PWM) Automation
+
+This automation module implements [Pulse Width Modulation (PWM)](https://en.wikipedia.org/wiki/Pulse-width_modulation).
+
+PWM can be used to control actuators continuously from 0 to 100% that only support ON/OFF commands.
+E.g. valves or heating burners.
+It accomplishes that by switching the actuator on and off with a fixed interval.
+The higher the control percentage (duty cycle), the longer the ON phase.
+
+Example: If you have an interval of 10 sec and the duty cycle is 30%, the output is ON for 3 sec and OFF for 7 sec.
+
+This module is **unsuitable** for controlling LED lights as the high PWM frequency can't be met.
+
+> Note: The module starts to work only if the duty cycle has been updated at least once.
+
+## Modules
+
+The PWM module can be used in openHAB's [rule engine](https://www.openhab.org/docs/configuration/rules-dsl.html).
+
+This automation provides a trigger module ("PWM triggers") with one input Item: `dutycycleItem` (0-100%).
+The module calculates the ON/OFF state and returns it.
+The return value is used to feed the Action module "Item Action" aka "send a command", which controls the actuator.
+
+To configure a rule, you need to add a Trigger ("PWM triggers") and an Action ("Item Action").
+Select the Item you like to control in the "Item Action" and leave the command empty.
+
+### Trigger
+
+| Name            | Type    | Description                                                                                  | Required |
+|-----------------|---------|----------------------------------------------------------------------------------------------|----------|
+| `dutycycleItem` | Item    | The Item (PercentType) to read the duty cycle from                                           | Yes      |
+| `interval`      | Decimal | The constant interval in which the output is switch ON and OFF again in sec.                 | Yes      |
+| `minDutyCycle`  | Decimal | Any duty cycle below this value will be increased to this value                              | No       |
+| `maxDutycycle`  | Decimal | Any duty cycle above this value will be decreased to this value                              | No       |
+| `deadManSwitch` | Decimal | The output will be switched off, when the duty cycle is not updated within this time (in ms) | No       |
+
+The duty cycle can be limited via the parameters `minDutycycle` and `maxDutyCycle`.
+This is helpful if you need to maintain a minimum time between the switching of the output.
+This is necessary for example for heating burners, which may not be switched on for very short times.
+The on time is than increased to `minDutycycle`.
+In this case one should also set a max duty cycle to prevent short off times.
+It makes sense to apply these symmetrically e.g. 10%/90% or 20%/80%.
+
+If the duty cycle is 0% or 100%, the min/max parameters are ignored and the output is switched ON or OFF continuously.
+
+If the duty cycle Item is not updated within the dead-man switch timeout, the output is switched off, regardless of the current duty cycle.
+The function can be used to save energy if the source of the duty cycle died for whatever reason and doesn't update the value anymore.
+When the duty cycle is updated again, the module returns to normal operation.
+
+> Note: The min/max ON/OFF times set via `minDutycycle` and `maxDutycycle` are not met if the dead-man switch triggers and recovers fast.
+
+## Control Algorithm
+
+This module is designed to respond fast to duty cycle changes, but at the same time maintain a constant interval and also the min/max ON/OFF parameters.
+For that reason, the module might seem to act peculiarly in some cases:
+
+- When the output is ON and the duty cycle is decreased, the output might switch off immediately, if applicable.
+Example: The interval is 10 sec and the current duty cycle is 80%.
+When the duty cycle is decreased to 20%, the output would switch off immediately, if it has been already ON for more than 2 sec.
+- When the duty cycle is 0% for a short interval and then increased again, the output will only switch on when the new interval starts.
+- When the duty cycle is 0% or 100% for more than a whole interval, a new interval will start as soon as the duty cycle is updated to a value other than 0%, respective 100%.
+- The module starts to work only if the duty cycle Item has been updated at least once.

bundles/org.openhab.automation.pwm/pom.xml

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+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>org.openhab.addons.bundles</groupId>
+    <artifactId>org.openhab.addons.reactor.bundles</artifactId>
+    <version>3.1.0-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>org.openhab.automation.pwm</artifactId>
+
+  <name>openHAB Add-ons :: Bundles :: Automation :: PWM</name>
+
+</project>

bundles/org.openhab.automation.pwm/src/main/feature/feature.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<features name="org.openhab.automation.pwm-${project.version}" xmlns="http://karaf.apache.org/xmlns/features/v1.4.0">
+	<repository>mvn:org.openhab.core.features.karaf/org.openhab.core.features.karaf.openhab-core/${ohc.version}/xml/features</repository>
+
+	<feature name="openhab-automation-pwm" description="PWM Automation" version="${project.version}">
+		<feature>openhab-runtime-base</feature>
+		<bundle start-level="80">mvn:org.openhab.addons.bundles/org.openhab.automation.pwm/${project.version}</bundle>
+	</feature>
+</features>

bundles/org.openhab.automation.pwm/src/main/java/org/openhab/automation/pwm/internal/PWMConstants.java

@@ -0,0 +1,35 @@
+/**
+ * Copyright (c) 2010-2021 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.automation.pwm.internal;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+
+/**
+ * Constants for the PWM automation module.
+ *
+ * @author Fabian Wolter - Initial Contribution
+ */
+@NonNullByDefault
+public class PWMConstants {
+    public static final String AUTOMATION_NAME = "pwm";
+
+    public static final String CONFIG_DUTY_CYCLE_ITEM = "dutycycleItem";
+    public static final String CONFIG_PERIOD = "interval";
+    public static final String CONFIG_MIN_DUTYCYCLE = "minDutycycle";
+    public static final String CONFIG_MAX_DUTYCYCLE = "maxDutycycle";
+    public static final String CONFIG_COMMAND_ITEM = "command";
+    public static final String CONFIG_DEAD_MAN_SWITCH = "deadManSwitch";
+    public static final String CONFIG_OUTPUT_ITEM = "outputItem";
+    public static final String INPUT = "input";
+    public static final String OUTPUT = "command";
+}

bundles/org.openhab.automation.pwm/src/main/java/org/openhab/automation/pwm/internal/PWMException.java

@@ -0,0 +1,29 @@
+/**
+ * Copyright (c) 2010-2021 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.automation.pwm.internal;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+
+/**
+ * Common exception for the PWM automation module.
+ *
+ * @author Fabian Wolter - Initial Contribution
+ */
+@NonNullByDefault
+public class PWMException extends Exception {
+    private static final long serialVersionUID = -3029834022610530982L;
+
+    public PWMException(String message) {
+        super(message);
+    }
+}

bundles/org.openhab.automation.pwm/src/main/java/org/openhab/automation/pwm/internal/factory/PWMModuleHandlerFactory.java

@@ -0,0 +1,64 @@
+/**
+ * Copyright (c) 2010-2021 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.automation.pwm.internal.factory;
+
+import java.util.Collection;
+import java.util.Set;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
+import org.openhab.automation.pwm.internal.handler.PWMTriggerHandler;
+import org.openhab.core.automation.Module;
+import org.openhab.core.automation.Trigger;
+import org.openhab.core.automation.handler.BaseModuleHandlerFactory;
+import org.openhab.core.automation.handler.ModuleHandler;
+import org.openhab.core.automation.handler.ModuleHandlerFactory;
+import org.openhab.core.items.ItemRegistry;
+import org.osgi.framework.BundleContext;
+import org.osgi.service.component.annotations.Activate;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Reference;
+
+/**
+ * Factory for the PWM automation module.
+ *
+ * @author Fabian Wolter - Initial Contribution
+ */
+@NonNullByDefault
+@Component(service = ModuleHandlerFactory.class, configurationPid = "automation.pwm")
+public class PWMModuleHandlerFactory extends BaseModuleHandlerFactory {
+    private static final Collection<String> TYPES = Set.of(PWMTriggerHandler.MODULE_TYPE_ID);
+    private ItemRegistry itemRegistry;
+    private BundleContext bundleContext;
+
+    @Activate
+    public PWMModuleHandlerFactory(@Reference ItemRegistry itemRegistry, BundleContext bundleContext) {
+        this.itemRegistry = itemRegistry;
+        this.bundleContext = bundleContext;
+    }
+
+    @Override
+    public Collection<String> getTypes() {
+        return TYPES;
+    }
+
+    @Override
+    protected @Nullable ModuleHandler internalCreate(Module module, String ruleUID) {
+        switch (module.getTypeUID()) {
+            case PWMTriggerHandler.MODULE_TYPE_ID:
+                return new PWMTriggerHandler((Trigger) module, itemRegistry, bundleContext);
+        }
+
+        return null;
+    }
+}