LoRaWAN: HomeAssistant Integration

[UBWH]

There is a feature where Tasmota can send an MQTT message that informs the Home Assistant (HA) Tasmota Integration of available sensors, and then HA adds those sensors automatically and starts capturing their values.

This feature fires (to my knowledge) just after boot up.

This does not work with LoRaWAN sensors (yet).

As a test, I manually sent an MQTT message from the Console as below (thank you google AI) and HA correctly added my LoRaWAN sensor. (Extra line breaks added for clarity)

publish2 homeassistant/sensor/tasmota_A8404192A35DCAC5_distance2/config 
{
"name":"Distance",
"uniq_id":"tasmota_A8404192A35DCAC5_distance",
"stat_t":"tele/LWG-T3S3_D91714/SENSOR/A8404192A35DCAC5",
"val_tpl":"{{value_json['LwDecoded']['DDS75L-Office'].Distance}}",
"unit_of_meas":"mm",
"dev":{
   "ids":["A8404192A35DCAC5"]
  }
}

I would like to open a discussion on the smartest way to add LoRaWAN sensors to the HA Tasmota integration.

1. Can the MQTT message be sent just after bootup?
   No. The way LoRaWAN works in Tasmota is that the necessary decoders are added at RUN time. When Tasmota starts it makes no assumptions as to which sensors are attached. Indeed, the design includes the feature that new LoRaWAN sensors can be added during run time.

2. When should the LoRaWAN homeassistant/sensor/xx MQTT message be sent?
   I propose it is part of the Berry code (LwDecode.be) that fires when a decoder is added at Run Time.

Anybody see any issues with this plan?

If not ... I will look at a PR to add this feature.

[arendst]

I suppose your current version of SO19 is 0. To initiate a rediscover try command SO19 0. This performs the same as the default discover 10 seconds after a restart.

Ah I see it doesn't add the LoRaWan sensor like it didn't add the zigbee sensors in the past.

11:30:34.964 MQT: tasmota/discovery/DC5475DFF088/config = {"ip":"192.168.2.138","dn":"LoraWan test","fn":["LoraWan test",null,null,null,null,null,null,null],"hn":"t3s3a","mac":"DC5475DFF088","md":"LilyGo T3S3 Lora32","ty":0,"if":0,"cam":0,"ofln":"Offline","onln":"Online","state":["OFF","ON","TOGGLE","HOLD"],"sw":"15.2.0.3","t":"t3s3a","ft":"%prefix%/%topic%/","tp":["cmnd","stat","tele"],"rl":[1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],"swc":[-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1],"swn":[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null],"btn":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],"so":{"4":0,"11":0,"13":0,"17":0,"20":0,"30":0,"68":0,"73":0,"82":0,"114":0,"117":0},"lk":0,"lt_st":0,"bat":0,"dslp":0,"sho":[],"sht":[],"ver":1} (retained)
11:30:34.970 MQT: tasmota/discovery/DC5475DFF088/sensors = {"sn":{"Time":"2026-01-30T11:30:34"},"ver":1} (retained)

EDIT1: I think your second solution looks best. Just keep a flag in memory for a one-time send if the sensor is first processed by LwDecode.be to not send it every time the same sensor is received.

[UBWH]

I do have one LoRaWAN sensor connected

But SO19 0 does not issue a homeasssistant/sensor/xxx/ MQTT message

12:32:35.974 CMD: SO19 0
12:32:35.975 SRC: WebConsole from 10.1.1.241
12:32:35.975 CMD: Grp 0, Cmd 'SO', Idx 19, Len 1, Pld 0, Data '0'
12:32:35.978 MQT: stat/LWG-T3S3_D91714/RESULT = {"SetOption19":"OFF"}
12:32:36.485 MQT: tasmota/discovery/B8F862D91714/config = {"ip":"10.1.1.9","dn":"Tasmota","fn":["Tasmota",null,null,null,null,null,null,null],"hn":"LWG-T3S3-D91714-5908","mac":"B8F862D91714","md":"LWG-T3S3","ty":0,"if":0,"cam":0,"ofln":"Offline","onln":"Online","state":["OFF","ON","TOGGLE","HOLD"],"sw":"15.2.0.3","t":"LWG-T3S3_D91714","ft":"%prefix%/%topic%/","tp":["cmnd","stat","tele"],"rl":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],"swc":[-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1],"swn":[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null],"btn":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],"so":{"4":0,"11":0,"13":0,"17":0,"20":0,"30":0,"68":0,"73":0,"82":0,"114":0,"117":0},"lk":0,"lt_st":0,"bat":0,"dslp":0,"sho":[],"sht":[],"ver":1} (retained)
12:32:36.492 MQT: tasmota/discovery/B8F862D91714/sensors = {"sn":{"Time":"2026-01-30T12:32:36"},"ver":1} (retained)

[arendst]

See my edit1 above.

[UBWH]

OK ... will see if i can put together a PR
:-)

[UBWH]

In trying to implement this, I have dived into the code and find two HA discovery implementations

And the code references these two functions

HAssDiscovery(); // Scheduled discovery using available resources
NewHAssDiscovery(); // Send the topics for Home Assistant Official Integration

My understanding this that NewHAssDiscovery() sends MQTT messages like:

tasmota/discovery/34B7DA5390B0/config = 
tasmota/discovery/34B7DA5390B0/sensors =

My understanding this that HAssDiscovery() sends MQTT messages like:

homeassistant/sensor/tasmota_xxxxx/config =  

My guess is:

• HAssDiscovery() is compatible with the generic way of advertizing sensors to HA
• NewHAssDiscovery() is compatible with the Tasmota Integration that can be installed in HA

Before I head down the wrong path, what should I be cloning in my implementation of advertizing LoRaWAN sensors to HA?

• HAssDiscovery() ?
• NewHAssDiscovery() ?

[arendst]

xdrv_12_discovery is the way to go. Forget about xdrv_12_home_assistant. The latter is disabled since years.

[UBWH]

Had some success

There are 3 methods to advertise sensors to HA

1. Tasmota Discovery message (at bootup) to Tasmota HA Integration with list of all known sensors
2. Generic HA Discovery MULTIPLE SENSOR message (at bootup) with list of all known sensors.
3. Generic HA Discovery SINGLE sensor messages

---

But because LoRaWAN sensors are not known at bootup what I have working is a hybrid solution:

1. Normal Tasmota Discovery message to Tasmota HA Integration at bootup with list of all sensors KNOWN AT THAT TIME

2. Generic HA Discovery Single Sensor messages that fire off when the LoRaWAN device decoder loads (i.e. when LoRaWAN data packet is received). One message per sensor.

---

The HA Single Sensor message code is all implemented in Berry

• Common code in LwDecode.be
• Device specific info in the device decoder files. This is optional: If it does not exist => nothing breaks, but no discovery messages sent for that device.

---

Comment: Reworking the main Tasmota code base to resend theTasmota Discovery message (method 1 above) to add LoRaWAN sensors when decoders are loaded was explored... but way too complicated.

---

Next steps:

1. Request for Comment: i.e. This post.
2. More testing.
3. PR with new berry code, and updated documentation

[UBWH]

See these PRs

#24458

tasmota/docs#1547