[velbus] Add VMB4LEDPWM-20 OnOff command support (openhab#18287)

* [velbus] update README

Signed-off-by: Daniel Rosengarten <[email protected]>

Author: Rosen01

bundles/org.openhab.binding.velbus/README.md

@@ -549,11 +549,11 @@ Thing velbus:vmbdali:1:01 [VL1="CH1,CH2,CH3,CH4", VL2="A4,A5,A6"]
 | `clockAlarm`              | `clockAlarm1WakeupHour`, `clockAlarm1WakeupMinute`, `clockAlarm1BedtimeHour`, `clockAlarm1BedtimeMinute`, `clockAlarm2WakeupHour`, `clockAlarm2WakeupMinute`, `clockAlarm2BedtimeHour`, `clockAlarm2BedtimeMinute` | Number                                                                  |                                                                                              |
 
 ### Module `vmb4ledpwm-20`
-| Supported channels groups | Supported channels     | Supported command types         | Remarks           |
-|---------------------------|------------------------|---------------------------------|-------------------|
-| `brightness`              | `CH1` ... `CH4`        | Percent                         |                   |
-| `fade-mode`               | `CH1` ... `CH4`        | Direct, Fade_Rate, Fade_Time    |                   |
-| `scene`                   | `CH1` ... `CH4`        | Number                          | Min = 1, Max = 15 |
+| Supported channels groups | Supported channels     | Supported command types         | Remarks                                                                                            |
+|---------------------------|------------------------|---------------------------------|----------------------------------------------------------------------------------------------------|
+| `brightness`              | `CH1` ... `CH4`        | OnOff, Percent                  | Sending an ON command will switch the dimmer to the value stored when last turning the dimmer off. |
+| `fade-mode`               | `CH1` ... `CH4`        | Direct, Fade_Rate, Fade_Time    |                                                                                                    |
+| `scene`                   | `CH1` ... `CH4`        | Number                          | Min = 1, Max = 15                                                                                  |
 
 ### Module `vmb8dc-20`
 | Supported channels groups | Supported channels     | Supported command types         | Remarks           |

bundles/org.openhab.binding.velbus/src/main/java/org/openhab/binding/velbus/internal/handler/VelbusNewDimmerHandler.java

@@ -29,6 +29,7 @@
 import org.openhab.binding.velbus.internal.packets.VelbusSetDimPacket;
 import org.openhab.binding.velbus.internal.packets.VelbusSetScenePacket;
 import org.openhab.core.library.types.DecimalType;
+import org.openhab.core.library.types.OnOffType;
 import org.openhab.core.library.types.PercentType;
 import org.openhab.core.library.types.StringType;
 import org.openhab.core.thing.ChannelUID;
@@ -196,6 +197,16 @@ public void handleCommand(ChannelUID channelUID, Command command) {
                 packet.setDim(colorChannel.getBrightnessVelbus());
                 packet.setMode(fadeModeChannels[Byte.toUnsignedInt(channel) - 1]);
                 velbusBridgeHandler.sendPacket(packet.getBytes());
+            } else if (command instanceof OnOffType onOffCommand) {
+                VelbusSetDimPacket packet = new VelbusSetDimPacket(address, channel);
+                if (onOffCommand == OnOffType.ON) {
+                    packet.setLastUsedDim();
+                } else {
+                    colorChannel.setBrightness(0);
+                    packet.setDim(colorChannel.getBrightnessVelbus());
+                }
+                packet.setMode(fadeModeChannels[Byte.toUnsignedInt(channel) - 1]);
+                velbusBridgeHandler.sendPacket(packet.getBytes());
             } else {
                 throw new UnsupportedOperationException(
                         "The command '" + command + "' is not supported on channel '" + channelUID + "'.");

bundles/org.openhab.binding.velbus/src/main/java/org/openhab/binding/velbus/internal/packets/VelbusSetDimPacket.java

@@ -40,6 +40,10 @@ public void setMode(byte mode) {
         data[3] = mode;
     }
 
+    public void setLastUsedDim() {
+        data[0] = COMMAND_RESTORE_LAST_DIMVALUE;
+    }
+
     @Override
     protected byte[] getDataBytes() {
         return data;