MQTT Group Topics

[NielsPiersma]

I would need MQTT Group Topics to work for provisioning and configuration purposes. In Tastmota we use "cmnd/tasmotas/"

I was hoping that in OpenBK this would relate to the Device Groups

But I can't get multiple devices to respond to commands I target there.

1) Is my assumption correct that device groups in OpenBK are not the same as Group Topics in Tasmota? 2) Can we have Group Topics in OpenBK? 3) Would the assumed syntax as "cmnd/[group topic]/power" and Payload 1 or 0 be correct?

Thanks Niels

[openshwprojects]

Tasmota Device groups are this: https://tasmota.github.io/docs/Device-Groups/ It has nothing to do with MQTT.

How group topics works? Are they... "listen only"?

So basically you want.... to set a group topic to "Bekens" on multiple devices, and then publish a "cmnd/Bekens/POWER" with "toggle" argument and they all listen and react?

What about replies - should the device publish something on group topic in a reply?

PS: "cmnd/bekendevice/power" with "0" or "1" or "toggle" already works

[NielsPiersma]

First, thanks for clarifying the difference between them. At least now it makes sense why I couldn’t get it to work.

From the device groups:

The device group name is set with the DevGroupName command (GroupTopic prior to v8.2.0.3). If a device group name is not set for a group, the MQTT group topic is used (with the device group number appended for device group numbers > 1). All devices in the same multicast network with the same device group name are in the same group. Some modules may define additional device groups. For example, if Remote Device Mode is enabled, the PWM Dimmer module defines three devices groups.

maybe it is the same, but we’re called grouptopic in the past, when untouched it looks like it becomes “group topic 1”

well group topic 1 (how I use it) works the same as the device topic. But all the devices subscribe to this topic. If I send a command like cmnd/tasmotas/reset 3 they reboot and recalibrate WiFi. I like doing this for general housekeeping and tidying. But the same goes for mass changing the SSID and WiFi password on a regular basis.

if a device published something in the group topic all subscribers will execute the received command. So not something I would expect regular.

so it is just like the normal full topic where the device receives it command from, but has a name that is shared over all devices. One command there is a command for all (subscribers).

I would not post or publish any reply into the group topic.

I can conform the P S: "cmnd/bekendevice/power" with "0" or "1" or "toggle" work fine. That what I was trying to expand.

Niels

[openshwprojects]

So basically:

1. add a field "GroupTopic" to gui
2. listen for commands on both cmnd/myBekenDevice1/POWER (etc etc) and /cmnd/myGroup/POWER
3. ... and execute those commands And that's all?

[NielsPiersma]

Yes, listen to both the cmnd/mybekendevice1/xyz and cmnd/mygroup/xyz

Niels

[openshwprojects]

added:

[NielsPiersma]

Super, I'll give it a try and let you know. Niels

[NielsPiersma]

Well, I tried, but no response (yet). I configured "bekens" as the secondary group topic.

cmnd/obkBF512F1E/Power Payload 1 == working cmnd/bekens/Power Payload 1 == not working.

Niels

[openshwprojects]

You must restart device for changes to take place.

[NielsPiersma]

I can confirm this is working as expected. Excellent!! Kudos! Niels