Meshtastic - LoRa-Mesh for Your Property: When Your Pond Tells You Itself

At some point, you walk out to your swimming pond again, look at the pressure gauge, and think: it’s due again. The filter needs backflushing, the pressure is too high - but you only noticed because you happened to pass by. Better would be: the thing just tells you itself.

That sounds like a minor inconvenience. Except it’s not when there’s no WLAN signal between your house and the pond, and laying cables isn’t an option. This is exactly where Meshtastic comes in - and it’s not what most people associate with it.

What is Meshtastic anyway?

Meshtastic is an open-source project that connects inexpensive LoRa-capable microcontrollers into a decentralized mesh radio network. No internet, no cellular, no central infrastructure. The devices communicate directly with each other - and over remarkable distances.

Originally, the project was mainly known in the outdoor and emergency communication community: hikers sending text messages when there’s no signal. That’s definitely cool - but I’m interested in a different angle: Meshtastic as a private sensor backbone for your property.

LoRa - the radio principle behind it

LoRa stands for Long Range and is a radio technology designed around one specific trade-off: little data, but great range and extremely low power consumption.

For comparison:

• WLAN sends a lot of data very quickly, but uses a lot of power and barely penetrates walls or longer distances.
• LoRa sends small amounts of data (bytes, not megabytes) very slowly - but over kilometers, through walls, trees, and on just a handful of milliwatts.

For sensor values - temperature, pressure, fill level - that’s ideal. A temperature reading is a few bytes. Transmitting it every 60 seconds doesn’t require WLAN.

The transmission works via license-free frequency bands (868 MHz in Europe), which you can use legally and without registration. This makes getting started simple and affordable.

How does a mesh network work?

A typical radio network has a central hub - a router, a base station. Everyone talks to the central hub, not to each other. If the hub fails, it’s over.

A mesh network works differently: each node can receive and retransmit messages. If device A sends a message that device C can’t receive directly, device B simply forwards it. The network grows with every device you add - and becomes more stable in the process, not more complicated.

In Meshtastic, this is called flooding: a message is relayed from node to node until it reaches its destination or hits a configured hop limit (3 hops by default). This prevents messages from circulating endlessly in the network.

For my scenario, this means: one node at the pond, another one somewhere halfway there (or simply a second node as a repeater), and the data reliably lands in the house - even if the direct connection alone wouldn’t be sufficient.

Meshtastic is more than text messages

Many people underestimate this on first glance: Meshtastic can’t just transmit text messages, it has a full telemetry mode. With it, you can transmit sensor data - temperature, air pressure, humidity, voltage, and much more - directly over the mesh network.

Each node can capture sensor data and feed it into the network. Another node that has a WLAN or Ethernet connection acts as an MQTT bridge and forwards the data into the home network. From there it lands in Home Assistant, Grafana, or whatever else you use.

That’s the decisive point: Meshtastic isn’t just a communication tool - it’s a radio infrastructure for distributed sensors that works without its own WLAN coverage.

The target image: Solar node at the swimming pond

My first productive node will be solar-powered right at the pond. It will capture:

• Water temperature surface - for a dashboard to keep an eye on the swimming factor
• Water temperature bottom - for comparison, interesting for layering in the pond
• Outdoor temperature - context for the water temperature values
• Filter pressure - and that’s the actually useful value: as soon as the pressure exceeds a defined threshold, I get a maintenance notification. Backflushing needed. No more guessing, no more random glances at the pressure gauge.

The temperatures land in a dashboard. The pressure triggers a notification. Simple, practical, and without a single WLAN antenna at the pond.

The hardware - a brief overview

For my test setup and first productive nodes, I’m using:

RAK WisBlock - a modular system where you simply plug sensor, radio, and base boards together. Extremely flexible, direct sensor connection, very power-efficient. This will be the pond solar node.

Seeed SenseCAP Indicator - a finished node with a large touchscreen display. Good for a stationary overview in the house - all sensor values at a glance.

Seeed SensorHub LoRa L1 and SensorHub L1 ePaper - finished solar nodes where you barely need to solder. The L1 with ePaper display is particularly interesting for outdoor use because the display is readable in sunlight and consumes no power at rest. For outdoor mounting, I’ve printed appropriate housings myself:

I’ll go into the hardware in detail in a separate part of the series.

Outlook: What comes next

The WisBlock Ethernet gateway deserves its own post - it’s the heart of the whole system:

In the next part of the series, I’ll build the MQTT bridge with the RAK WisBlock and an Ethernet module. That’s the heart of the whole system: the node that mediates between the LoRa mesh and the home network, and ensures that sensor data from the pond ultimately arrives in Home Assistant.

After that comes the actual solar node setup.

Meshtastic is a rabbit hole. But a very useful one.