Mari is a lightweight wireless connectivity solution designed for dense IoT networks, with a focus on supporting real-time interactions and fast over-the-air (OTA) updates.

The driving use case for the design of Mari is the OpenSwarm Testbed of 1,000 DotBots. Mari is suitable for any dense IoT deployment requiring low-latency communication.

This repository ships two halves:

• firmware/ — the C firmware that implements the Mari TSCH-over-BLE link layer on Nordic nRF52840 / nRF5340.
• marilib/ — the Python control plane (mari-edge, mari-cloud CLI agents) that talks to a Mari gateway over UART or MQTT and renders a Rich-based real-time TUI.

Each half is self-contained: its build config, tests, and examples live in its own directory.

• TSCH over BLE: Time-Synchronized Channel Hopping (TSCH) over Bluetooth Low Energy 2 Mbps PHY
• Multi-Gateway Architecture: scale by adding more gateways
• Non-Coordinated Gateways: gateways are independent — infrastructure setup is simple
• Fast Handovers: quick transitions between gateways as nodes move
• Low-Power Operation: energy-efficient for battery-powered devices
• Real-Time Communication: 100–150 ms average latency with 100 nodes per gateway
• Reasonable Throughput for OTAP: about 10 Kb/s downlink
• Quick Network Join: 150 ms best-case, 6 s worst-case
• Dense Network Support: scales for hundreds to thousands of nodes

mari/
├── firmware/       # C firmware (mari TSCH-over-BLE link layer)
│   ├── app/        # Applications and tests
│   ├── drv/        # Hardware drivers
│   ├── mari/       # Core protocol implementation
│   └── nRF/        # Nordic Semiconductor SDK files
└── marilib/        # Python package + tests + examples
    ├── marilib/    # The importable Python package
    ├── tests/
    ├── examples/
    ├── pyproject.toml
    └── install_marilib.sh

Validated on Nordic nRF52833, nRF52840, and nRF5340 (dual-core; gateway on the network core).

cd firmware
make node        # nrf52840dk node
make gateway     # nRF5340 net-core gateway
make all         # default
make docker      # CI path (Docker-wrapped SEGGER ES)

The project uses SEGGER Embedded Studio .emProject files, clang-format v15, and pre-commit (root config).

// Gateway init
mari_init(MARI_GATEWAY, MARI_NET_ID_DEFAULT, schedule, event_callback);

// Node init
mari_init(MARI_NODE, MARI_NET_ID_PATTERN_ANY, schedule, event_callback);

To run a Mari network on your computer, follow the wiki: https://github.com/DotBots/mari/wiki/Getting-started#running-mari-network-on-your-computer

cd marilib
python -m venv .venv && source .venv/bin/activate
pip install -e .

For a Raspberry Pi edge node, ./install_marilib.sh (inside marilib/) bootstraps a venv and installs the package.

mari-edge  -m mqtts://argus.paris.inria.fr:8883           # UART-attached gateway
mari-cloud -n 0x0100 -m mqtts://argus.paris.inria.fr:8883 # cloud bridge over MQTT

mari-edge --help documents all flags. The TUI shows real-time network state with an ASN-decomposed latency breakdown (host/dl/app/ul) and a Q (sf) column for per-node uplink-queue depth — see marilib/AGENTS.md for column semantics.

import time
from marilib.marilib import MarilibEdge
from marilib.serial_uart import get_default_port

def main():
    mari = MarilibEdge(lambda event, data: print(event.name, data), get_default_port())
    while True:
        for node in mari.gateway.nodes:
            mari.send_frame(dst=node.address, payload=b"A" * 3)
        time.sleep(0.25)

if __name__ == "__main__":
    main()

More examples in marilib/examples/.

cd marilib
hatch test                                   # pytest --doctest-modules --cov=marilib
hatch fmt --check
hatch build

This repository uses gitflow: develop is the integration branch, main is releases. Feature branches off develop; PRs target develop.

If you are an AI coding agent working in this repo, read AGENTS.md (cross-cutting), firmware/AGENTS.md, and marilib/AGENTS.md.

Apache 2.0 — see LICENSE.

• Fedrecheski et al., "Mari: Connecting Large Scale Robot Swarms over BLE using TSCH with Multiple Independent Gateways", CrystalFreeIoT Workshop 2025 [Forthcoming]

This project has received funding from the EU's Horizon Europe Framework Programme under Grant Agreement No. 101093046.