set volume

src/defaultAccessory.ts

@@ -58,9 +58,38 @@ export class DefaultPlatformAccessory {
         }
       });
 
+    const speakerService: Service = this.accessory.getService(`${displayName} Speaker`) ||
+      this.accessory.addService(this.platform.Service.Speaker, `${displayName} Speaker`);
+    speakerService.getCharacteristic(this.platform.Characteristic.Volume)
+      .onSet(async (value: CharacteristicValue) => {
+        try {
+          if (!this.connected()) {
+            return;
+          }
+          await this.platform.robovac.setVolume(value as Number);
+        } catch (error: unknown) {
+          this.platform.log.error(error as string);
+        }
+      });
+
+    const updateVolumeLevel = () => {
+      if (!this.connected()) {
+        return;
+      }
+      try {
+        speakerService.updateCharacteristic(this.platform.Characteristic.Volume, this.platform.robovac.volume());
+      } catch (error: unknown) {
+        this.platform.log.error(error as string);
+      }
+    };
+
+    this.platform.robovac.on('tuya.data', updateVolumeLevel);
+
     this.platform.robovac.on('event', (event: RobovacEvent) => {
       if (event.command === 'battery') {
         updateBatteryLevel();
+      }  else if (event.command === 'volume') {
+        updateVolumeLevel();
       } else if (event.command === 'locate') {
         findMyRobot.updateCharacteristic(this.platform.Characteristic.On, event.value as boolean);
       }