Heltec V4: Integrations. Home Assistant, Telegram, Monitoring. Part 3

📌 This is Part 3 of the series. Part 1: Theory, Part 2: Practice.

🔗 What We’re Integrating

Component	Purpose	Difficulty
ONEmesh MQTT	Bridge between local mesh and global map + Telegram notifications	🟢 Low
Home Assistant	Node sensors, device_tracker, automations on mesh messages	🟡 Medium
Notifications	Alerts for new nodes, lost connection, mentions in chat	🟢 Low

💡 All examples tested on: HA 2026.4.2 (Docker) + Orange Pi 3B + built-in MQTT broker.

🌐 Step 1: Configure Meshtastic MQTT for ONEmesh

Connection Parameters

Parameter	Value	Note
MQTT Address	`mqtt.onemesh.ru`	Community server
Username	`onemesh`	Default
Password	`onecat`	Shared for all
Root topic	`msh/RU/XXX`	`XXX` = city code (list)
TLS enabled	`Yes`	Try `No` if not working
JSON enabled	`Yes`	Required for Home Assistant
Uplink / Downlink	`Yes` / `No`	Uplink only is enough for monitoring

⚠️ Important: Firmware 2.5+ supports new encryption key format (PKI). If using encryption - ensure keys are synced across nodes.

How to Verify

Enable JSON enabled in MQTT settings
Connect to broker via mosquitto_sub or MQTT Explorer:

mosquitto_sub -h mqtt.onemesh.ru -u onemesh -P onecat \
  -t 'msh/RU/MOW/json/#' -v

You’ll see messages like:

{
  "id": 452664778,
  "from": 2130636288,
  "payload": {
    "text": "Hello from local mesh!",
    "battery_level": 87,
    "voltage": 4.12
  },
  "type": "text",
  "timestamp": 1714234567
}

📬 Step 2: Telegram Notifications via ONEmesh Bot

ONEmesh automatically forwards messages from your city topic to a private chat with the bot.

Notification Examples

[26.04.2026 20:52] ONEmesh Bot: LF | qwrt (https://map.onemesh.ru/?node_id=483535916)  QWRT Pocket
20, standard. but for home node - triad antenna
SNR 4.75  RSSI -92  HopLimit 3
- data from 44b4 (https://map.onemesh.ru/?node_id=49169588)

Field	Meaning	Why it matters
`SNR`	Signal-to-Noise Ratio	Signal quality: higher = better
`RSSI`	Received Signal Strength	Signal power: closer to 0 = better
`HopLimit`	Remaining hops	Shows how far message traveled

Setup

Find @ONEmeshBot in Telegram
Send /start - bot will show instructions
Ensure your node sends data to MQTT with correct root topic
Done: notifications will arrive automatically

💡 Tip: if no notifications - check that OK to MQTT is enabled in channel settings and node has internet.

🏠 Step 3: Home Assistant Integration

Prerequisites

Built-in MQTT broker in HA (Settings → Devices & Services → MQTT)
Meshtastic node with JSON enabled in MQTT
Access to configuration.yaml and ability to create mqtt.yaml

Step 3.1: Connect MQTT in HA

# configuration.yaml
mqtt: !include mqtt.yaml

# mqtt.yaml
broker: core-mosquitto # or your broker address
port: 1883
username: homeassistant
password: !secret mqtt_password
# For external broker (e.g., ONEmesh):
# broker: mqtt.onemesh.ru
# port: 8883
# username: onemesh
# password: onecat
# certificate: /config/certs/ca.crt  # for TLS

Step 3.2: Create Sensors for Node

# mqtt.yaml - continued
sensor:
  # Node battery
  - name: "Meshtastic Node Battery"
    unique_id: "meshtastic_node_battery"
    state_topic: "msh/RU/MOW/json/LongFast/!abcd1234"
    value_template: >-
      {% if value_json.from == 2130636288 and value_json.payload.battery_level is defined %}
        {{ value_json.payload.battery_level | int }}
      {% else %}
        {{ this.state }}
      {% endif %}
    unit_of_measurement: "%"
    device_class: battery

  # Voltage
  - name: "Meshtastic Node Voltage"
    unique_id: "meshtastic_node_voltage"
    state_topic: "msh/RU/MOW/json/LongFast/!abcd1234"
    value_template: >-
      {% if value_json.from == 2130636288 and value_json.payload.voltage is defined %}
        {{ value_json.payload.voltage | float | round(2) }}
      {% else %}
        {{ this.state }}
      {% endif %}
    unit_of_measurement: "V"
    device_class: voltage

  # Channel utilization (airtime load)
  - name: "Meshtastic Channel Utilization"
    unique_id: "meshtastic_chutil"
    state_topic: "msh/RU/MOW/json/LongFast/!abcd1234"
    value_template: >-
      {% if value_json.from == 2130636288 and value_json.payload.channel_utilization is defined %}
        {{ value_json.payload.channel_utilization | float | round(1) }}
      {% else %}
        {{ this.state }}
      {% endif %}
    unit_of_measurement: "%"

🔑 Important: replace 2130636288 with your node’s decimal from (find via MQTT Explorer or meshtastic --info).

Step 3.3: Location Tracking (device_tracker)

# automations.yaml
- alias: "Meshtastic: Update node location"
  trigger:
    platform: mqtt
    topic: "msh/RU/MOW/json/LongFast/!abcd1234"
    value_template: >-
      {% if value_json.from == 2130636288 and 
            value_json.payload.latitude_i is defined and 
            value_json.payload.longitude_i is defined %}on{% endif %}
  action:
    service: device_tracker.see
    data:
      dev_id: "meshtastic_node_1"
      gps:
        - "{{ (trigger.payload_json.payload.latitude_i | int * 1e-7) }}"
        - "{{ (trigger.payload_json.payload.longitude_i | int * 1e-7) }}"
      battery: "{{ states('sensor.meshtastic_node_battery') | default(0) }}"

💡 Meshtastic stores coordinates as integer * 1e7, so multiply by 1e-7 to get real values.

Step 3.4: Notifications on Chat Mentions

# automations.yaml
- alias: "Meshtastic: Notify on mention"
  trigger:
    platform: mqtt
    topic: "msh/RU/MOW/json/LongFast/!abcd1234"
    value_template: >-
      {% if value_json.type == "text" and 
            value_json.payload.text is defined and 
            "ponf" in value_json.payload.text.lower() %}on{% endif %}
  action:
    service: notify.mobile_app_your_phone
    data:
      title: "📡 Meshtastic"
      message: "Mention: {{ trigger.payload_json.payload.text }}"
      data:
        priority: high

🔐 Security: Encryption and Keys

What Changed in Firmware 2.5+

Version	Key Type	Notes
< 2.5	Single `PSK` per channel	Simple setup, but vulnerable if compromised
≥ 2.5	`PKI` + `shared secret`	Separate keys for encryption and authentication

How to Configure Encryption

In Meshtastic app: Channel → Primary → PSK
- Enable encryption
- Copy the key (same AQ== for primary channel)
In MQTT settings: Encryption enabled → Yes
Ensure all nodes in mesh use the same key

⚠️ Critical: if keys don’t match - messages arrive but won’t decrypt. Verify via MQTT Explorer.

Where to Store Keys

✅ In secrets.yaml Home Assistant (don’t commit to Git!)
✅ In password manager (Bitwarden, KeePassXC)
❌ Not in public repos, logs, or screenshots

⚠️ Common Issues

Symptom	Cause	Fix
Sensors not updating	Wrong `from` in `value_template`	Find node’s decimal ID via `meshtastic --info`
No Telegram messages	Wrong `root topic`	Check city code: `msh/RU/MOW`, `msh/RU/SPB`, etc.
Encryption not working	Keys don’t match	Copy `PSK` exactly, no spaces, to both nodes
`device_tracker` not moving	Coordinates in wrong format	Multiply `latitude_i`/`longitude_i` by `1e-7`
HA won’t connect to broker	Wrong credentials	Check `username`/`password` and port (1883/8883)

🔗 What We’re Integrating#

🌐 Step 1: Configure Meshtastic MQTT for ONEmesh#

Connection Parameters#

How to Verify#

📬 Step 2: Telegram Notifications via ONEmesh Bot#

Notification Examples#

Setup#

🏠 Step 3: Home Assistant Integration#

Prerequisites#

Step 3.1: Connect MQTT in HA#

Step 3.2: Create Sensors for Node#

Step 3.3: Location Tracking (device_tracker)#

Step 3.4: Notifications on Chat Mentions#

🔐 Security: Encryption and Keys#

What Changed in Firmware 2.5+#

How to Configure Encryption#

Where to Store Keys#

⚠️ Common Issues#

Links#

🔗 What We’re Integrating

🌐 Step 1: Configure Meshtastic MQTT for ONEmesh

Connection Parameters

How to Verify

📬 Step 2: Telegram Notifications via ONEmesh Bot

Notification Examples

Setup

🏠 Step 3: Home Assistant Integration

Prerequisites

Step 3.1: Connect MQTT in HA

Step 3.2: Create Sensors for Node

Step 3.3: Location Tracking (device_tracker)

Step 3.4: Notifications on Chat Mentions

🔐 Security: Encryption and Keys

What Changed in Firmware 2.5+

How to Configure Encryption

Where to Store Keys

⚠️ Common Issues

Links