Switching from v1.5 MQTT gateway to ESP8266 MQTT Client gateway

[Matt Pitts]

@mbj now worries, thanks for helping me out, I'm running openHAB as a serivce my my rpi2 along with mosquitto.

I have noticed these occasional messages in the event.log:

2016-02-13 20:36:25.823 [DEBUG] [o.o.i.m.i.MyOpenHABServiceImpl] - store(lounge_Temp), state = 23.0

I also checked by subscribing with mosquitto _sub client and get the following.

mosquitto_sub -d -t mygateway1-out/3/0/1/0/1
Client mosqsub/14104-raspberry sending CONNECT
Client mosqsub/14104-raspberry received CONNACK
Client mosqsub/14104-raspberry sending SUBSCRIBE (Mid: 1, Topic: mygateway1-out/3/0/1/0/1, QoS: 0)
Client mosqsub/14104-raspberry received SUBACK
Subscribed (mid: 1): 0
Client mosqsub/14104-raspberry sending PINGREQ
Client mosqsub/14104-raspberry received PINGRESP
Client mosqsub/14104-raspberry sending PINGREQ
Client mosqsub/14104-raspberry received PINGRESP
Client mosqsub/14104-raspberry sending PINGREQ
Client mosqsub/14104-raspberry received PINGRESP
Client mosqsub/14104-raspberry received PUBLISH (d0, q0, r0, m0, 'mygateway1-out/3/0/1/0/1', ... (4 bytes))
37.0
Client mosqsub/14104-raspberry sending PINGREQ
Client mosqsub/14104-raspberry received PINGRESP

I don't really know what this should look like, but from my very basic understanding it looks like messages are at least being published. Otherwise OpenHab wouldn't be able to do this

[mbj]

@Matt-Pitts When running Openhab as a daemon some typical listings in my event.log are:

2016-02-14 08:05:24 - node2_pulsecounter_in state updated to 30568
2016-02-14 08:05:24 - Kwh_node2 state updated to 30.5680
2016-02-14 08:05:24 - Kwh_diff state updated to 0.8050
2016-02-14 08:05:25 - Temp_node2_freezer state updated to -19.4
2016-02-14 08:05:53 - Temp_dining state updated to 21.9

Your listing:
2016-02-13 20:36:25.823 [DEBUG] [o.o.i.m.i.MyOpenHABServiceImpl] - store(lounge_Temp), state = 23.0
shows that Openhab has received this value and updated the state. My guess is that you run Openhab with debug output enabled. At least I get this logging format but then in openhab.log when I run from a debug shell.

For moquitto you will see all messages if you subscribe to topic # and if you set the -v flag also the output is a bit more verbose, example:
mosquitto_sub -h 192.168.1.107 -t # -v (I need the -h switch because I do not run it from localhost)

A typical output gives topic and payload and looks like:
mygateway1-out/24/1/1/0/0 -10.6
mygateway1-out/24/2/1/0/1 96

Your topic line will show just this the topic mygateway1-out/3/0/1/0/1 and the -d flag shows debug values.

Since you get a log message and also the graph these values of course must be coming in so if this is the only incoming value you have all is OK. If you have more sensors sending which do not show up in the log then most likely there are errors in the mqtt binding for these items.

Just a comment, in your previous post about the openhab.cfg one line for the broker states:

mqtt-eventbus:commandSubscribeTopic=mygateway1-in/commandUpdates/${item}/command

I think this should be changed to
mqtt-eventbus:commandSubscribeTopic=mygateway1-out/commandUpdates/${item}/command

[DirkB19]

@mbj said:

mqtt-eventbus:broker=mosq1
mqtt-eventbus:stateSubscribeTopic=MyMQTT-2/stateUpdates/${item}/state
mqtt-eventbus:commandSubscribeTopic=MyMQTT-2/commandUpdates/${item}/command

Hi mbj,
I'm following you on this thread now :) Because I'm also on OpenHAB.

Just some questions ,
1 Could you confirm if the following topic structure change is correct in my item bindings ;
BEFORE =
Number BadK_TempDH "T. BADKAMER [%.1f °C]" { mqtt="<[RPIBroker:MyMQTT/25/11/V_TEMP:state:default]"
AFTER =
Number BadK_TempDH "T. BADKAMER [%.1f °C]" { mqtt="<[RPIBroker:MyMQTT/25/11/1/0/0::state:default]"

2. Think it matters if the in- and outgoing TOPIC is the same ?
   So instead of
   incoming to Openhab: {mqtt="<[RPIBroker:mygateway1-out/22/1/1/0/17:state:default]"}
   outgoing from Openhab {mqtt=">[RPIBroker:mygateway1-in/22/1/1/0/24:state::default]"}
   I would have ;
   incoming to Openhab: {mqtt="<[RPIBroker:MyMQTT/22/1/1/0/17:state:default]"}
   outgoing from Openhab {mqtt=">[RPIBroker:MyMQTT/22/1/1/0/24:state::default]"}

Thing is, I wanna make sure before I start changing 40-50 item definitions.
Thx again,
DirkB

[mbj]

@DirkB19 Hi Dirk,
Looking at this link http://forum.mysensors.org/topic/2352/guide-setting-up-and-testing-mqtt-client-gateway you will find the new topic to be MY_MQTT_PUBLISH_TOPIC_PREFIX/FROM-NODE-ID/SENSOR-ID/CMD-TYPE/ACK-FLAG/SUB-TYPE . Thus the difference is the added /CMD-TYPE/ACK-FLAG/ plus that the V_XXXX is changed to the corresponding number. So to me your item 1 change looks perfectly OK.

Your item 2 is a bit unclear to me and these are of course dependent on your definitions in the sketch. I did use the preset data so my incoming to Openhab typically looks like:

{mqtt="<[mosq1:mygateway1-out/22/1/1/0/25:state:default]"}

And the outgoing (in this case a command) :

{mqtt=">[mosq1:mygateway1-in/27/1/1/0/24:command:*:default]"}

The in- and outgoing need a different definition (mygateway-out versus mygateway-in in these examples) as far as I can understand from the publish/subscribe logic in MQTT.

Hope it makes sense.

[DirkB19]

@mbj

thanks, meanwhile I've changed all my item definitions, and I can confirm the following ;

1. new topic definition is OK, it works :)
2. I confirm it works with the same MY_MQTT_PUBLISH_TOPIC_PREFIX for both in and out, simply "MyMQTT" in my case.

Next hurdles are ;
3. convert all my nodes to DEVELOPMANT BRANCH LIBRARIES, using info from : http://forum.mysensors.org/topic/2742/problem-compiling-sketch-on-library-1-5-devel/2
I've got one node converted now and it seems to work, except that the DHT22 sensor now seems to report in Fahrenheit (before it was in Celcius) ? Strange is that before I uploaded the node with dev libs I had accidentally reset it and from then (even with 1.5 LIBS) it started reporting temp in Fahrenheit to my MQTT client gateway on DEV LIBS ?

[mbj]

@DirkB19
I have not looked into what happens when using same prefix so this is just an unconfirmed thought:

The MQTT broker relays any message received to anybody listening. So when using same prefix for publish and subscribe there ought to be a risk that your gateway reads and forwards to the sending node same message which it just did send.

Many nodes do not read incoming messages and then this does not matter but for nodes reading incoming messages then there might be some issues if , for example, the outgoing message being interpreted as an incoming setpoint.

Would be interesting to hear if anybody knowing the details could comment on this.

I have at least one node running with DHT22 and the code from the development branch and without any problems. Just one thought - this code is using a different DHT library compared to the v1.5 version if I remember right. Nothing you have overlooked there?

[martinhjelmare]

For the mqtt model of communication to be able to support two way communication, publish and subscribe topics can't be the same at each device.

Comm goes like this:

point1 -> publish -> broker -> subscribe -> point2
point1 <- subscribe <- broker <- publish <- point2

So each device, point1 and point2, in the example above, must have at least two different topics, one for publishing and one for subscribing to messages, to enable both sending and receiving messages.

For pure sensors devices that only send/publish messages, the publish topic is the only relevant one. But since for mysensors, this is set up at the gateway, for all nodes, no matter if they are pure sensors or if they are actuators, you have to have different publish and subscribe prefixes to the topics.

From the dev branch 5100 mqtt gateway sketch:

// Set this nodes subscripe and publish topic prefix
#define MY_MQTT_PUBLISH_TOPIC_PREFIX "mygateway1-out"
#define MY_MQTT_SUBSCRIBE_TOPIC_PREFIX "mygateway1-in"

I'm not sure exactly how the mqtt is set up in openhab, but if openhab should be able to both send and receive messages via mqtt it will need to handle both publish and subscribe topics and those should not be the same.

[mbj]

@martinhjelmare
Thank's for the explanation which follows what is my own understanding of the MQTT setup and procedures.

When defining items in Openhab obviously there is no problem handling both publish and subscribe topics.

[DirkB19]

And still, I have it working both ways with the same MY_MQTT_PUBLISH_TOPIC_PREFIX for in and out going messages.
I have sensors and actuators both working (still on 1.5 LIBS but I guess that has nothing to do with it ?).
But just to be sure, I will change it to 2 different TOPIC_PREFIXes as suggested in above posts.
Thx.

[mbj]

@DirkB19 Think you will get another advantage by changing as well - must be a lot easier to monitor the MQTT messages when topic clearly shows the difference.