In practice you have two paths:

1. Active mode – a device (e.g., Raspberry Pi Zero 2 W / 2 W with Bluetooth) connects to the sensor over BLE and reads data via GATT.
2. Passive mode (advertising) – the sensor broadcasts data in BLE advertisements, and the receiver only listens (no pairing and no persistent connections).

Active mode: quick start, higher battery drain​

In active mode the Raspberry Pi acts like a BLE client: it connects to the sensor and reads measurements.

Pros

• Very fast setup (especially if you already have a Pi with Bluetooth).
• Good control over when/how often you read data.

Cons

• Frequent connections and data exchange usually mean faster battery drain in the sensor.
• With more sensors, the “connection management” cost grows (time, interference, scheduling).

Passive mode (advertising): best balance for battery and scale​

In passive mode the sensor sends data in BLE advertisements and the receiver only listens. In real homes this often wins: it’s lighter and scales better.

The key idea is switching the firmware to one that broadcasts sensor data (e.g., ATC / PVVX), so:

• the receiver doesn’t need to connect to the sensor,
• there’s no constant BLE “back-and-forth” between two devices,
• the sensor battery usually lasts longer.

Required step for passive mode: Mi Home + token/bindkey​

To flash LYWSD03MMC without soldering, a typical flow looks like this:

1. Add the sensor to Xiaomi Mi Home (bind the device to your account).
2. Extract credentials (tokens / bindkey) via a token extractor.
3. Use a BLE web flasher (TelinkMiFlasher) and flash a broadcasting firmware (e.g., PVVX).

Note: details depend on your sensor revision and current firmware—always follow the instructions for your exact device/firmware.

Flashing: TelinkMiFlasher (PVVX)​

The flasher works in the browser (Web Bluetooth; Chrome recommended), so you don’t need a programmer or soldering:

• https://pvvx.github.io/ATC_MiThermometer/TelinkMiFlasher.html

After a successful flash you can configure the advertising mode and other broadcast parameters.

BLE → MQTT bridge: ESP32 or Raspberry Pi​

On the receiver side you usually pick one of these:

• ESP32 (e.g., OpenMQTTGateway) scans BLE and publishes to MQTT.
• Raspberry Pi scans BLE locally and publishes to MQTT (or runs a gateway that does it).

Nettemp (via nettemp config) can “wire” this setup so data ends up on your MQTT broker and then in Nettemp Cloud / Docker.

Quick checklist (very short)​

1) Add to Xiaomi Mi Home​

• Add the sensor in the Mi Home app (account binding is needed to get keys).

2) Token extractor (token/bindkey)​

• https://github.com/PiotrMachowski/Xiaomi-cloud-tokens-extractor

3) Flash PVVX via TelinkMiFlasher​

• Open: https://pvvx.github.io/ATC_MiThermometer/TelinkMiFlasher.html
• Connect
• Provide token and BLE KEY / bindkey (if required for your variant)
• Start flashing
• After success: connect again (Connect) and set advertising parameters, e.g.:
  • Advertising type: ATC1441
  • AdFlags
  • (optional) Get name / Set name
• Send Config → Disconnect

• ESP32 with OpenMQTTGateway (active BLE scanning, Wi‑Fi uplink)
• Raspberry Pi with Bluetooth running nettemp client + nettemp config (passive BLE sniffing)

Both paths deliver the same result—BLE sensor data lands in Nettemp over MQTT—the only difference is the device doing the listening.

Flashing OpenMQTTGateway on ESP32​

1. Go to https://docs.openmqttgateway.com/upload/web-install.html
2. Connect the ESP32 by USB.
3. Select esp32dev-ble.
4. Connect to the temporary Wi‑Fi SSID broadcast by the ESP32.
5. In the installer, set Wi‑Fi credentials and the MQTT broker IP/host (must be done here; later edits are limited in 1.8.0/1.8.1).
6. Finish the install and reboot the ESP32.

Running on Raspberry Pi​

If you already have a Pi with Bluetooth, you can keep everything on one box:

• Start nettemp client and use nettemp config to enable the MQTT bridge and subscriber rules.
• Let it listen passively for BLE beacons and forward readings to your Nettemp MQTT broker.

Known issues / tips​

• Chrome flashing glitch? Restart Chrome and retry the web installer.
• Set the MQTT server IP during the Wi‑Fi setup step—later edits are blocked in OMG 1.8.0/1.8.1.
• In nettemp config you can auto-discover topics, and subscribe with one save.

links​

https://github.com/1technophile/OpenMQTTGateway

• Two-way MQTT: Nettemp Client ingests data from wireless devices (e.g., ESP running ESP Mega firmware) and forwards it to Nettemp Docker or Nettemp Cloud. It can also publish its own readings back to your broker.
• Expanded Xiaomi support: It adds the Xiaomi Mi Temperature & Humidity Monitor 2 (LYWSD03MMC). Turn the sensor on, let Nettemp detect it—no Xiaomi app needed. A Raspberry Pi Zero 2W with built-in Bluetooth works great here.
• Easier configuration: Clear options with hints in Nettemp Client Installation. Enable MQTT, pick your server, review the detected sensor, and turn on only what you need.

What is NetTemp?​

NetTemp is an IoT sensor monitoring platform designed for Raspberry Pi and Linux devices. It combines:

• Easy hardware support - 22+ sensor types, plug-and-play
• Real-time dashboards - See your data instantly
• Smart alarms - Get notified before problems occur
• Cloud or self-hosted - You choose where your data lives

What You'll Need​

1. Hardware

   • Raspberry Pi (any model) or Linux device
   • At least one sensor (DHT22, BME280, DS18B20, etc.)
   • MicroSD card with Raspberry Pi OS

2. Account

   • Free NetTemp account at app.nettemp.pl

3. Time

   • About 10 minutes for initial setup

Step-by-Step Setup​

1. Create Your Account​

Head to app.nettemp.pl and register:

Email: your@email.com
Password: ••••••••

After registering, verify your email. You'll be redirected to the dashboard.

2. Get Your API Key​

In the dashboard:

1. Click Settings → API Tokens
2. Click Generate New Token
3. Give it a name like "Living Room Pi"
4. Copy the token (starts with ntk_)

⚠️ Important: Save this token! You'll need it in step 4.

3. Install Client on Raspberry Pi / Linux​

📖 For detailed setup with interactive configuration tool, see the Nettemp Client Installation documentation

The installation guide covers everything: automatic setup, sensor configuration, hardware discovery, and troubleshooting.

View Your Data​

Back in your browser, go to app.nettemp.pl:

Overview Tab​

You'll see a tile for your device showing:

• Device name ("living-room-1")
• Latest sensor readings
• Last update time
• Green status badge (online)

Click the tile to see all sensors from this device.

Charts Tab​

Click Charts to visualize your data:

• Select sensor(s) to plot
• Choose time range (1h, 6h, 24h, 7d, 30d)
• Zoom and pan to explore
• Hover to see exact values

My View Tab​

Create a custom dashboard:

1. Click My View → Edit Mode
2. Click + Add Value Tile
3. Select your sensor
4. Drag to position
5. Click Save

You can add gauges, mini charts, and floor plans too!

What's Next?​

Now that you have data flowing, here are some ideas:

Set Up Alarms​

Get notified when temperature goes too high:

1. Go to Alarms tab
2. Click New Alarm
3. Configure:
   • Sensor: living-room-1 → Temperature
   • Condition: Temperature > 25°C
   • Cooldown: 60 minutes
4. Add notification:
   • Channel: Email
   • Template: Default
5. Click Save

Now you'll get an email if temperature exceeds 25°C!

Add More Sensors​

See the Client Installation Guide for 22+ supported sensor types and configuration examples.

Create Floor Plans​

If you have a floor plan image:

1. Go to My View → Edit Mode
2. Upload floor plan (Settings → Devices → Upload Plan)
3. Add Plan Tile to your dashboard
4. Position sensors on the plan
5. See real-time status on your floor plan!

Export Data​

Need your data in Excel/CSV?

1. Go to Charts
2. Select sensor and time range
3. Click Export CSV
4. Open in Excel, Google Sheets, etc.

Troubleshooting​

Having issues? The interactive configuration tool can help diagnose problems:

nettemp config

Use the tool's features:

• Discover Devices - Check if sensors are detected
• Test Sensor Readings - Verify sensors are working
• System Management → Check Status - See if client is running

For detailed troubleshooting steps, see the Client Installation Guide.

Getting Help​

Stuck? We're here to help!

• Documentation: Full guides at nettemp.pl
• Discord: Live chat at discord.gg/S4egxNvQHM

Next Steps​

Explore the NetTemp Cloud dashboard to discover all features including sensor configuration, alarm setup, custom dashboards, and API integration.

Welcome to the NetTemp community! 🎉

We can't wait to see what you build. Share your setup in our Discord!