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MQTT Integration

Connect EMS-ESP to your home automation system via MQTT

📊 Published Data

When MQTT is enabled, EMS-ESP will publish MQTT topics for each device. The frequency can be configured from the WebUI to be either sent when data changes are detected or set to a specific period in seconds which is kinder on network traffic.

🔍 MQTT Discovery

When MQTT Discovery is enabled, EMS-ESP will automatically create special Discovery topics (with /config) for each EMS device entity that has received a valid value.

📋 Data Formats

The table below lists the topics being published. The format shown is the MQTT Format as defined in EMS-ESP's settings. Default format is Nested which uses a single topic to show multiple entries in the payload.

📋 MQTT Topics Reference

Topic Format Description Payload Example
status n/a MQTT will and testament messages online or offline
info n/a System information and events {"version":"3.7.2","hostname":"ems-esp"}
heartbeat all System stats in JSON (default every minute) {"bus_status":"connected","uptime":"02:16:00"}
tapwater_active all Boolean: hot tap water running (DHW) -
heating_active all Boolean: heating is on -
boiler_data all Non warm water data from Boiler device {"heatingactive":"off","curflowtemp":57.5}
thermostat_data nested Thermostat data and Heating Circuits {"hc1":{"seltemp":15.0,"mode":"auto"}}
thermostat_data_hc<id> single Individual heating circuit data {"seltemp":15,"mode":"auto"}
mixer_data nested Mixer data with hc1-hc4 and wwc1, wwc2 {"hc1":{"flowTemp":55,"pumpStatus":"on"}}
shower_data all Shower timer and alert toggles {"timer":"0","duration":"4m 32s"}
solar_data all Solar Module data (if connected) {"collectorTemp":15.8,"energyToday":1792}
temperaturesensor_data nested External Dallas temperature sensors {"28-233D-9497":{"temp":19.6}}
analogsensor_data nested External analog sensors {"31":{"name":"analog31","value":0}}
custom_data nested Custom entities -

📤 Using MQTT to Send Commands

🔧 Command Reference

Learn how to use MQTT to send commands to EMS-ESP for controlling your heating system.

View Commands Guide

📊 Monitoring MQTT Traffic

🔍 MQTT Explorer

For precise monitoring of MQTT traffic, I suggest using MQTT Explorer. This tool provides a visual interface to monitor all MQTT topics and messages.

💻 Console Commands

Use the console command show mqtt to display the status of the MQTT service, topic subscriptions, and outbound publishing queue.

📈 WebUI Status

In the WebUI you can see the size of the queue and overall stats are available in the Status page.