@masmat - I am far from an OpenHAB expert but... The sitemap in OpenHAB is only needed to view the status of (or interact with) the item. It is not required for the functionality of an item or thing itself.
Have you checked your logs to see if there are clues when OpenHAB parses the things/items filed?
Please start another thread and post your .things, .items, .sitemap files and a log extract there so we can have a look at them.
@fixjunk Thanks for responding - I have tried Domoticz and considered HASS but OpenHAB is the only controller that also supports my AllPlay speakers.
Anyway, I gave up and reinstalled Openhabian. It breaks my heart to admit but it also gave me a chance to fix a few bugs and try some new things on the server.
Net result: On a clean Openhabian 2.2 install with only the Eclipse MQTT bundle installed, the "Persistence in use" warning is still triggered. (I won't look further into it, it's only a warning.) The MySensors 2.3 binding connects as expected to the MQTT gateway and everything seems to work again.
Well, not really. I managed to break both of my sensors while experimenting. So I guess I'm back to soldering tomorrow. 
@fixjunk - I'm having the same problem and it's driving me crazy. I don't mind some troubleshooting but OpenHAB is new territory for me and I just can't find the problem.
I have set up two mqtt broker connections (in two config files) for debugging. For the Eclipse bundle I define the connection "huset_mqtt" with user "openhab". For the legacy OpenHAB binding I define a connection "huset_mqtt_legacy" with user "openhab-legacy. Both connect to the same mosquitto server.
I don't think there is a conflict between the openHAB MQTT Binding and esh-io-transport-mqtt. To test it I stopped the openHAB MQTT binding and transport bundles. The warning is still there even when only the Eclipse SmartHome MQTT Transport Bundle is running.
When all bundles are running, I first stop the legacy broker and the log looks as expected. But when I restart the Eclipse bundle the warning "Persistence already in use" is thrown (below):
2018-05-04 22:10:09.739 [INFO ] [penhab.io.transport.mqtt.MqttService] - Stopping broker connection 'huset_mqtt_legacy'
2018-05-04 22:17:47.270 [INFO ] [.transport.mqtt.MqttBrokerConnection] - Starting MQTT broker connection 'huset_mqtt' to 'tcp://
192.168.1.5:1883' with clientid OpenHab and file store '/var/lib/openhab2/tmp/huset_mqtt'
2018-05-04 22:17:47.349 [WARN ] [rthome.io.transport.mqtt.MqttService] - MqttBroker start failed: Persistence already in use
org.eclipse.smarthome.io.transport.mqtt.MqttException: Persistence already in use
at org.eclipse.smarthome.io.transport.mqtt.MqttBrokerConnection.start(MqttBrokerConnection.java:572) [214:org.eclipse.sm
arthome.io.transport.mqtt:0.10.0.b1]
However, it is clear that the Eclipse broker connection does not fail completely. Mosquitto logs and mqtt-spy confirm that both transports/binding actually connect to the mosquitto server. One at a time or both at the same time.
Below is the mosquitto log when I restart the OpenHAB MQTT transport, the OpenHAB MQTT binding and last the Eclipse MQTT transport. Clearly the clients disconnect and then reconnects like they should.
1525466428: Client OpenHab_legacy disconnected.
1525466428: New connection from 192.168.1.5 on port 1883.
1525466428: New client connected from 192.168.1.5 as OpenHab_legacy (c1, k60, u'openhab-legacy').
1525466645: Saving in-memory database to /var/lib/mosquitto/mosquitto.db.
1525467392: Client OpenHab_legacy disconnected.
1525467393: New connection from 192.168.1.5 on port 1883.
1525467393: New client connected from 192.168.1.5 as OpenHab_legacy (c1, k60, u'openhab-legacy').
1525467446: Client OpenHab disconnected.
1525467446: New connection from 192.168.1.5 on port 1883.
1525467446: New client connected from 192.168.1.5 as OpenHab (c1, k60, u'openhab').
To test the two mqtt broker connections I have set up test switches in an .items file:
Switch MQTT_TEST_legacy "Testing..." { mqtt="<[huset_MQTT_legacy:testing/mqtt/topic:state:default], >[huset_MQTT_legacy:testing/mqtt/back-topic:command:*:default]" }
Switch MQTT_TEST_new "Testing..." { mqtt="<[huset_MQTT:testing/mqtt/topic:state:default], >[huset_MQTT:testing/mqtt/back-topic:command:*:default]" }
To test them I manually send the message "ON" to the topic "testing/mqtt/topic". The MQTT_TEST_legacy switch state changes to ON. So the legacy OpenHAB binding works fine.
However, the MQTT_TEST switch that uses the Eclipse mqtt broker/transporrt does not respond at all to my messages.
To summarize, the Eclipse mqtt feature throws a warning but connects to my mosquitto server,and then wont change items with messages I send.
Am I missing a component, or what could possibly be the reason?
It is a basic, fresh install of OpenHAB 2.2 on openhabian. I have cleaned caches and tmp, cleaned up config files in /var/lib/openhab/config and even reinstalled OpenHAB. The Mysensors binding 2.2.0.201710190834 is running.
Now I don't even have a clue on what to check next.
OpenHAB gurus out there - please help me!
Can you please add a link/button at the top of the page - Download and installation - that links to https://github.com/tobof/openhab2-addons/wiki
It is a very useful page but also very hard to find.
The two middle buttons should preferably be removed as the "Support Forum" button is sufficient.
What's your best advice on buying components to your projects?
I've recently gotten started and built a couple of MYS nodes and other Arduino projects. The local electronics store (Radioshack-style) are happy to sell me much of what I need - ranging from Pro Minis and sensors to boxes and battery holders. But they charge 5-20 times more than Aliexpress and eBay. On the other hand, quality varies when ordering from China and delivery times are painful at best.
With the mindboggling number of sellers on eBay and Aliexpress, I often find myself spending too much time optimizing orders, trying to order from a minimal number of trustworthy suppliers. (I really prefer to have 2 and not 20 separate deliveries.)
On the other side of the spectrum there is Farnell, RS Components, Distrelec etc. They have slightly better prices than my local stores and unbeatable delivery times. But the sheer number of components they provide is often too much for me. (165 different rotary encoders to choose from at RS!)
How do you cope?
Do you have an online shopping strategy to relieve some of the pain?
Favourite suppliers?
My wishlist for a supplier include:
Or is that too much to ask for?
@neverdie said in What did you build today (Pictures) ?:
Maybe you speaker geniuses can figure out the optimal enclosure for this tiny buzzer?
I'll play my "I am not a speaker designer, but..." card! Here is some basic info. 
Jokes aside, a piece of PVC tubing might work. You need something to make the buzzer move the air more efficiently. I'd put a 1/4 wavelength long PVC piping over the buzzer as
a first try. (Any odd multiple of 1/4 wavelength should provide some resonance.)
In a more elaborate design, you could try a simple horn. Aim for a size where both the length of the horn and its circumference at the end is ca 1 wavelength.
@scalz That looks very neat and tempting indeed! A pair of Overnight Sensation has long been in the plans for my next (and first) speaker build. Where did you get the components?
You are of course both right! It was only intended to get things going so I didn’t want to complicate things. My “production” sensors will be quite different. Maybe I’ll save this one in a frame on the wall 
Great fun to see all these build pictures!
My pic of the day is a trivial battery powered DHT22 sensor just to try things out with prototyping, programming and connecting to OpenHAB. This is my first project since highschool. (The gw and first sensor is on a breadboard.)
It feels great to be soldering again after almost 30 years and I'm really looking forward to step into the MySensors world!
Thanks for some great work @TimO ! Version 2.2 now works smoothly with my simple OpenHAB setup (2.2 snapshot).
One thing I noticed is that the gateway thing configuration page says "Disable network sanity check" even though the logic has been reversed in v2.2.
So the UI needs to be similarly changed to "Enable startup check" instead.
While I'm at it, could you please also clarify (in the UI) what "Send delay" is? Please also add that timing is in ms. If I understand things correctly it could say "Minimum time between messages sent to the gateway (ms)"
Also, the comment for "Imperial/Metric selection" could use some clarification. Preferably change the label to "Imperial units" and the explanation to "Use imperial units (default is metric)."
And finally it would be great to add add that the time is given in "...(minutes)" for the Network sanity check interval.
