sim-mesh is a LoRa testbed. Its stations are real firmware, built for Linux and run as ordinary processes, each on its own loopback address; below their radio driver sits a model of the radio chip on a virtual SPI bus, and between the models sits one medium, the ether, which decides who hears what from a table of every pair’s path loss over real or synthetic ground. A map in the browser places the nodes and shows every frame on the air. It is the firmware under test, built for a different target — not an emulator.

A run goes in real time, for working with stations by hand, or in virtual time, as fast as the stations can compute: an hour of a busy network in seconds, the same frames at the same instants in every run of one seed.

• Get startedClone, start, add firmware, run a script. Docker or Podman is all it needs.
• Pre-built firmwareStation builds ready to add, for aarch64 and x86_64.
• Bring your firmwareThe zip, its driver, the ether's protocol and the virtual radio, specified.

What it is made of

browser ── localhost:8800 ──► front ─┬─► simd (one simulation) ─┬─ ether      who hears what
                                     │                          ├─ stations   firmware processes, one pty each
                                     │                          └─ proxy      each station's own web UI
                                     ├─► a script's runner, driving one simulation
                                     └─► the planner: real ground, built from public sources

One simulation is one simd; the front runs several behind one port, computes their loss tables, runs scripts against them and builds real ground from public data. Around them are the things sim-mesh keeps:

• firmware — station builds, each a zip with its own driver, installed from a file or from the pre-built ones;
• geodata — the ground, a pack built from public sources or synthetic;
• nodesets — which nodes stand where, with what antenna and power;
• scripts — plain Python that says what each node runs and what is done;
• runs and snapshots — what a simulation did, and moments of it to start again from.

sim-mesh holds nothing of any one firmware project. A firmware tells sim-mesh how to talk to it through its driver, a Python module in its own zip, and a script asks for the same things — an announce, a message, a path — of every firmware of a category. Reticulum firmware is the first category; MeshCore and Meshtastic are next.

Source: github.com/sim-mesh/sim-mesh, Apache 2.0.