What Am I doing Wrong?

[evilpete]

I am trying to feed data from my outdoor temperature sensor (LaCrosse-TX141Bv3).

I'm receiving the data using an SDR dongle and passing it via mqtt.

The data I'm sending to MQTT:

{"time" : "2025-08-07 13:39:10", "protocol" : 73, "model" : "LaCrosse-TX141Bv3", "id" : 237, "channel" : 1, "battery_ok" : 1, "temperature_C" : 20.800, "test" : "No"}

This is the json output from rtl_433

 

My devfile:

devices:
 - id: "TX141Bv1"
   sensor_id: "temperature_C"
   type: "Temp"
   name: "Temperature"
   status_topic: "rtl_433/LaCrosse-TX141Bv3/temperature_C"
   cmd_topic: "rtl_433/LaCrosse-TX141Bv3/power"
 - id: "TX141Bv2"
   sensor_id: "battery_ok"
   type: "raw"
   name: "Battery"
   status_topic: "rtl_433/LaCrosse-TX141Bv3/battery_ok"
   cmd_topic: "rtl_433/LaCrosse-TX141Bv3/power"
 - id: "TX141Bv4"
   sensor_id: "test"
   type: "flag"
   name: "testFlag"
   status_topic: "rtl_433/LaCrosse-TX141Bv3/test"
   cmd_topic: "rtl_433/LaCrosse-TX141Bv3/power"

MQTT Explorer reports:

. 

But Im seeing 

.  

any suggestions?

I'm guessing I am misinterpreting fieldnames? 

 

 

[TriLife]

Hi @evilpete,

The MQTT plug-in was designed for Tasmota integrations. Tasmota doesn't send JSON packets, only individual data points.

I think @sjenkins added one or two devices, which send JSON packets. He might be able to shed more light to see, if using his device-type will better match your needs.

[evilpete]

Thanks  I'll do more studying..

I found a few filters that grok the json and publish the filtered results. 

[sjenkins]

@evilpete , your issue is these devices do not read a JSON string from MQTT but rather individual variables.

so your MQTT should look more like this..... (sorry this isn't a raw example but the form factory holds).  You will need to write your JSON string using each variable.

Does not matter if your device is Tasmota or not ; in fact when I started using, then modifying this plugin I didn't know what Tasmota was & still have never used one.  What matters is the form it hits the MQTT ; that's the beauty of MQTT !

Not sure if you are sending with Python or with C, C# but works similar in both, the topic in the below case is /sej/awning/status/hb while the message is ON.  You are sending the whole JSON as one message in a topic.

hope that helps

 

 

Edited Saturday at 01:29 PM by sjenkins

[sjenkins]

A quick Python example from my Copilot friend:

 

Here's a Python function that takes a JSON array and sends each item to a separate MQTT topic using the paho-mqtt library:

import json
import paho.mqtt.client as mqtt

def send_json_array_to_mqtt_topics(json_array, topic_prefix, mqtt_host='localhost', mqtt_port=1883): 
""" Sends each item in a JSON array to a separate MQTT topic. Parameters: - json_array (list): A list of JSON-serializable items. - topic_prefix (str): Prefix for MQTT topics (e.g., 'sensor/data'). - mqtt_host (str): MQTT broker host. - mqtt_port (int): MQTT broker port. """
  client = mqtt.Client() client.connect(mqtt_host, mqtt_port, 60) 
  for i, item in enumerate(json_array):
    topic = f"{topic_prefix}/{i}" 
    payload = json.dumps(item) 
    client.publish(topic, payload) 
    print(f"Published to {topic}: {payload}") 
  client.disconnect() 

Example usage:

data = [{"temp": 22.5}, {"temp": 23.0}, {"temp": 21.8}] 
send_json_array_to_mqtt_topics(data, "sensors/temperature") 

 

This will publish each dictionary in the array to a topic like:
- sensors/temperature/0
- sensors/temperature/1
- sensors/temperature/2
 

[evilpete]

@sjenkins thanks

I'll probably have to write a plug-in that interprets the output of rtl-433.

it's written in C and the code focuses on SDR protocol decoding thus the input format is not gonna change (I contributed to code base a few years ago)

after looking around they have some example code that does something similar for another product.


Side Note:   once done it will be trivial to incorporate pre-existing devices as input sensors

Tire pressure:

{"time" : "2025-08-04 18:22:45", "protocol" : 186, "model" : "Hyundai-VDO", "type" : "TPMS", "id" : "5173f60b", "state" : 48, "flags" : 8, "repeat" : 1, "pressure_kPa" : 248.875, "temperature_C" : 25.000, "maybe_battery" : 1, "mic" : "CRC"}

Home security sensors (admittedly the neighbors')

{"time" : "2025-06-30 22:14:47", "model" : "Interlogix-Security", "subtype" : "unknown", "id" : "51a4c2", "battery_ok" : 0, "switch1" : "CLOSED", "switch2" : "CLOSED", "switch3" : "OPEN", "switch4" : "CLOSED", "switch5" : "CLOSED", "raw_message" : "d24000"}

Efergy home energy meter (also the neighbors', but hey, it's good for development input data)

{"time" : "2025-07-31 19:01:36",  "protocol" : 100, "model" : "Efergy-e2CT", "id" : 16386, "battery_ok" : 0, "current" : 18.781, "interval" : 6}

Rolling code Keyfobs

{"time" : "@0.843604s",   "protocol" : 164, "model" : "Secplus-v2", "id" : 1959100928, "button_id" : 16, "remote_id" : 1959100928, "fixed" : "70678577664", "rolling" : "240124739"}

Motion sensors

{time" : "2024-09-27 19:28:26", "model" : "Skylink motion sensor", "motion" : "true", "id" : "1e3e8", "raw" : "be3e8"}

Edited Saturday at 08:46 PM by evilpete

[sjenkins]

@evilpete your other option is to add a device to the mqtt plugin & do a pull request.  Take a look at the github, the code is pretty simple.  Less work than a whole plugin.

https://github.com/Trilife/udi-mqtt-pg3x

 

[evilpete]

5 hours ago, sjenkins said:

@evilpete your other option is to add a device to the mqtt plugin & do a pull request.  Take a look at the github, the code is pretty simple.  Less work than a whole plugin.

https://github.com/Trilife/udi-mqtt-pg3x

 

Yeah, now that i understand what is going on more that's what I've thinking about with a few translation table based on protocol number...

I was trying to use it as it at first not realizing it was special case mostly for Tasmota integrations

Edited yesterday at 01:41 AM by evilpete