FieldMesh – a simple way to build small off-grid networks with MeshCore

In situations like music festivals or outdoor activities, it quickly becomes clear how dependent groups are on working mobile networks. Once those networks get overloaded, even basic coordination becomes difficult. That’s exactly the kind of practical problem FieldMesh was built to address.

Why I started looking into this

I regularly visit larger music festivals. On the festival grounds, the mobile network is usually so overloaded that communication within the group becomes almost impossible. Traditional radios are also not an option at many events due to strict security controls. That’s when I started looking into mesh networks.

My first experience was with Meshtastic. Its strength is clearly in small, spontaneous ad-hoc networks — which is exactly what you want in those situations.
The problem is that you don’t only use this kind of hardware in off-grid scenarios. Once you have it, you tend to use it in everyday situations as well — at home, in your city, or between nearby areas.
That’s where things started to break down for me. The network becomes very busy, a lot of telemetry is being sent, and actual communication becomes less reliable.
So while Meshtastic works well for small, local setups, it didn’t really fit my everyday use case.

With MeshCore, that changed.
It uses airtime more efficiently, generates less unnecessary traffic, and overall feels much more stable in everyday use.

Where MeshCore didn’t quite fit my use case

That said, there was still a gap.
MeshCore works really well when there is some form of infrastructure.
But as soon as you’re completely on your own — no repeater, no coverage — things get more complicated.

Client Repeat already provided the technical foundation for small local networks. But actually using it in the field wasn’t very practical. Switching frequencies, adjusting parameters, remembering settings — it’s not something you want to deal with in that moment.

The idea behind FieldMesh

The initial idea was simple:
Create a preset that covers exactly that use case.

A quick way to switch into a local off-grid network, without manual configuration.
And more importantly: simple enough that you can hand a device to someone who has never used mesh networking before.

That’s how FieldMesh started

Over time, more features were added, all focused on making that use case easier.

A central part of this is automatic tracking.
Nodes send adverts at fixed intervals, including their position. These are displayed separately: RECENT shows all recently received nodes, while TRACKING only shows nodes that have sent GPS data, including a calculated distance.
Distance is calculated once when a message is received and should be treated as a rough estimate. The goal is not precise positioning, but to quickly understand how far someone is roughly located.

Another important aspect is how the system behaves on the network.

In normal operation, adverts are deliberately kept local (zero-hop). This follows one of MeshCore’s core principles: using available bandwidth efficiently and avoiding unnecessary traffic.
As soon as off-grid mode is enabled, this behavior changes automatically. Adverts are then flooded to allow small local networks to form without existing infrastructure.
The user doesn’t have to think about this or change settings — the system adapts to the situation.

There is also a simple SOS feature, designed for local use. In situations where direct communication is no longer possible, it is often enough to trigger a signal within local range.

Context

FieldMesh is not a fully planned product.
It grew out of a specific need and developed over time.

I’m not a developer, and I built this out of personal interest. Because of that, the current state is quite pragmatic.

Some things are still hardcoded, and hardware support is limited simply because I don’t have access to more devices.

GitHub & what’s next

f you want to take a look or try it yourself:

https://github.com/TogeriX-hub/FieldMesh

Feedback, ideas, or real-world experiences are always welcome.Als nächste Schritte schaue ich mir aktuell vor allem an:

Right now, I’m mainly looking at:

• improving the messaging interface

• making off-grid configuration more flexible

• taking inspiration from existing custom firmware (e.g. Wio Tracker L1)

FieldMesh started as a simple idea — and grew from there.