# MicroMesh 📻

**A tiny, dependency-free Meshtastic client for MicroPython.**

MicroMesh lets a small MicroPython board talk to a Meshtastic radio over UART. Use it
to receive messages, send text and position packets, inspect the node list, or power a
full-screen terminal dashboard.

No protobuf compiler runs on the board. No threads. No `google.protobuf`. Just a UART,
three wires, and regular Python.

> [!NOTE]
> MicroMesh is young and intentionally small. It supports the most useful Meshtastic
> client operations, but it is not yet a complete replacement for the official desktop
> [`meshtastic`](https://github.com/meshtastic/python) package.

## What can it do?

- Connect to a Meshtastic radio using its framed serial API
- Download and track the radio's node database
- Receive and send text messages
- Send binary data and positions
- Read user, position, signal, battery, and hop information
- Preserve unknown protobuf fields for forward compatibility
- Recover from serial noise and skip newer messages it cannot decode
- Run a curses dashboard with live stats, nodes, and messages
- Work on MicroPython without third-party runtime dependencies

## Pick your setup

| I want to… | Use this |
| --- | --- |
| Run a simple listener on a XIAO RP2040 | [XIAO quick start](#xiao-rp2040-quick-start) |
| View nodes and messages through my XIAO | [Curses dashboard](#curses-dashboard-through-the-xiao) |
| Connect my computer directly to the Meshtastic radio | [Direct desktop dashboard](#direct-to-radio-dashboard) |
| Use a Pico, Pico W, or ESP32 | [Other boards](#other-boards) |
| Write my own program | [Python API](#python-api) |

## How the XIAO setup works

The XIAO is the computer running MicroMesh. The Meshtastic device is the LoRa radio.

```text
 Mac / PC                    XIAO RP2040                 Meshtastic radio
┌─────────┐   USB/REPL    ┌────────────────┐   UART    ┌─────────────────┐
│ terminal│◀─────────────▶│ MicroPython +  │◀────────▶│ Meshtastic      │◀──▶ LoRa
│ or UI   │               │ MicroMesh      │ 3 wires  │ firmware        │
└─────────┘               └────────────────┘          └─────────────────┘
```

The XIAO does not contain a LoRa radio. It controls a separate Meshtastic device over
UART.

## Before you begin

You need:

- A Seeed Studio XIAO RP2040 with MicroPython installed
- A separate Meshtastic-compatible radio running Meshtastic firmware
- Three jumper wires for TX, RX, and GND
- A data-capable USB cable for the XIAO
- Python 3 on your Mac, Linux computer, or Windows PC

Configure the Meshtastic radio's serial interface for:

```text
Enabled: yes
Mode:    PROTO
Baud:    115200
```

The radio's UART pin names depend on its model. Consult that board's pinout before
connecting wires.

> [!CAUTION]
> Use **3.3 V UART logic** and always connect the grounds. Do not connect the boards'
> power pins unless you have verified their voltage and current requirements.

## XIAO RP2040 quick start

### 1. Wire the boards

UART wires cross: TX goes to RX, and RX goes to TX.

```text
XIAO RP2040                         Meshtastic radio
────────────────────────────────────────────────────
D6 / GPIO0 / UART0 TX  ──────────▶ UART RX
D7 / GPIO1 / UART0 RX  ◀────────── UART TX
GND                    ─────────── GND
```

The XIAO D6/D7 mapping comes from the
[`XIAO RP2040 pinout`](https://wiki.seeedstudio.com/XIAO-RP2040/).

### 2. Prepare a Python environment

Run these commands from the MicroMesh repository directory:

```sh
python3 -m venv .venv
source .venv/bin/activate
python -m pip install --upgrade mpremote
```

Windows PowerShell uses this activation command instead:

```powershell
.venv\Scripts\Activate.ps1
```

### 3. Find the XIAO serial port

Connect the XIAO over USB, then run:

```sh
mpremote connect list
```

On macOS it will usually look similar to `/dev/cu.usbmodem2101`. Linux commonly uses
`/dev/ttyACM0`; Windows uses a name such as `COM4`.

The commands below use `/dev/cu.usbmodem2101`. Replace it with your port.

### 4. Install MicroMesh on the XIAO

```sh
mpremote connect /dev/cu.usbmodem2101 mip install package.json
```

This installs the `micromesh` package under `/lib` on the board.

### 5. Run the example

The example broadcasts one `hello from XIAO RP2040` message after each successful
configuration download. Comment out its `mesh.sendText(...)` line first if you want a
receive-only test.

```sh
mpremote connect /dev/cu.usbmodem2101 run examples/xiao_rp2040.py
```

You should immediately see:

```text
MicroMesh starting on XIAO RP2040
UART0: D6/GPIO0 TX -> radio RX
UART0: D7/GPIO1 RX <- radio TX
UART0: 115200 baud; common GND required
configuration requested; id=...
```

When the radio finishes sending its configuration and node database:

```text
radio configuration complete; sending greeting
connected; 17 nodes known
```

The number of nodes will be different for your radio. Press `Ctrl-C` to stop.

### 6. Start it automatically

Once the temporary run works, save it as the XIAO boot program:

```sh
mpremote connect /dev/cu.usbmodem2101 fs cp examples/xiao_rp2040.py :main.py
mpremote connect /dev/cu.usbmodem2101 reset
```

To stop or replace an automatically running script, connect the XIAO, press `Ctrl-C`
in `mpremote repl`, and upload a different `main.py`.

## Curses dashboard through the XIAO

The desktop curses dashboard provides keyboard message composition and a resizable UI.
It displays live connection stats, known nodes, battery levels, SNR, hops, last-seen
times, and incoming messages. The XIAO runs a small bridge between the radio UART and
the dashboard over USB.

The dashboard needs a small bridge program on the XIAO. The regular
`xiao_rp2040.py` example prints human-readable logs; it does not expose structured data
to desktop applications.

### 1. Install the desktop dependencies

```sh
source .venv/bin/activate
python -m pip install -e . pyserial
```

Windows users also need:

```powershell
python -m pip install windows-curses
```

### 2. Install the bridge on the XIAO

This replaces the current `main.py`:

```sh
mpremote connect /dev/cu.usbmodem2101 fs cp examples/xiao_dashboard_bridge.py :main.py
mpremote connect /dev/cu.usbmodem2101 reset
```

### 3. Close `mpremote`, then launch the dashboard

```sh
python examples/curses_dashboard.py --xiao-bridge /dev/cu.usbmodem2101
```

Only one application can own a serial port. Close `mpremote`, Arduino Serial Monitor,
screen, minicom, and other serial tools before launching the dashboard.

The message field is always active. Type a message and press Enter—there is no separate
compose mode.

| Key | Action |
| --- | --- |
| Type + Enter | Broadcast the text in the message field |
| Escape | Clear the message field |
| `F5` (or `Ctrl-R`) | Request the configuration and node database again |
| `F10` (or `Ctrl-Q`) | Quit cleanly |

To switch back to the regular logging example:

```sh
mpremote connect /dev/cu.usbmodem2101 fs cp examples/xiao_rp2040.py :main.py
mpremote connect /dev/cu.usbmodem2101 reset
```

## Direct-to-radio dashboard

If the Meshtastic radio itself is connected to your computer over USB, the desktop can
talk directly to it. Do not use `--xiao-bridge` in this mode.

```sh
python -m pip install -e . pyserial
python -m serial.tools.list_ports -v
python examples/curses_dashboard.py /dev/cu.YOUR_RADIO_PORT
```

The XIAO's USB port identifies as a MicroPython board. Direct mode will not work with
that port; use `--xiao-bridge` when the radio is wired through the XIAO.

## Other boards

Ready-to-run examples are included for common MicroPython boards:

| Board | Example | UART | TX | RX |
| --- | --- | --- | --- | --- |
| Seeed Studio XIAO RP2040 | [`xiao_rp2040.py`](examples/xiao_rp2040.py) | UART0 | D6 / GPIO0 | D7 / GPIO1 |
| Raspberry Pi Pico / Pico W | [`raspberry_pi_pico.py`](examples/raspberry_pi_pico.py) | UART0 | GP0 | GP1 |
| Generic ESP32 | [`esp32.py`](examples/esp32.py) | UART2 | GPIO17 | GPIO16 |

Change the UART and pin numbers if your board uses a different mapping. See the
complete [examples guide](examples/README.md) for wiring notes.

## Troubleshooting

### `could not enter raw repl`

Use the exact port instead of `connect auto`:

```sh
mpremote connect list
mpremote connect /dev/cu.usbmodem2101 exec "print('MicroPython REPL OK')"
```

If it still fails, close every other serial application, unplug and reconnect the
XIAO, and try again.

### It repeatedly says `waiting for radio data`

The XIAO is running, but no complete Meshtastic frame has arrived. Check:

1. XIAO D6/TX goes to radio RX—not radio TX.
2. XIAO D7/RX goes to radio TX.
3. Both boards share GND.
4. The radio UART is enabled in `PROTO` mode at 115200 baud.
5. The configured radio UART pins match the pins you physically connected.

### The desktop curses dashboard stays at `configuration requested`

If the radio is wired through the XIAO, install `xiao_dashboard_bridge.py` as
`main.py` and include `--xiao-bridge` in the dashboard command. Without the bridge,
the desktop sends Meshtastic data to the MicroPython REPL instead of UART0.

Also confirm that `mpremote` or another serial monitor is not holding the port.

### The node count appears, but no messages appear

The node list is stored data downloaded from the radio. It is not a message history.
Send a **new** text from another Meshtastic node while MicroMesh is running.

### A frame is skipped or reports a decode error

Meshtastic's protobuf schema evolves. MicroMesh reports and skips newer messages that
its compact schema does not yet understand. Text and other supported packets continue
processing. Update the installed files after pulling a newer MicroMesh version:

```sh
mpremote connect /dev/cu.usbmodem2101 mip install package.json
```

### The serial port is busy

One port can have only one owner. Quit the dashboard before using `mpremote`, and close
`mpremote` before restarting the dashboard.

## Python API

Here is the smallest useful program:

```python
from machine import Pin, UART
from time import sleep_ms

from micromesh import PortNum, SerialInterface


def received(packet):
    if packet.WhichOneof("payload_variant") != "decoded":
        return
    if packet.decoded.portnum == PortNum.TEXT_MESSAGE_APP:
        print("from !%08x: %s" % (
            packet.from_,
            packet.decoded.payload.decode("utf-8"),
        ))


uart = UART(0, 115200, tx=Pin(0), rx=Pin(1), timeout=0, rxbuf=1024)
mesh = SerialInterface(uart, on_packet=received)
mesh.connect()

while True:
    mesh.poll()
    sleep_ms(10)
```

### Send packets

```python
# Broadcast text on the primary channel
mesh.sendText("hello mesh")

# Direct message with an acknowledgement
mesh.sendText("hello", destinationId="!a1b2c3d4", wantAck=True)

# Position packet
mesh.sendPosition(45.5152, -122.6784, altitude=15)

# Custom application data
mesh.sendData(b"custom", portNum=PortNum.PRIVATE_APP)
```

Payloads may be at most 233 bytes. `poll()` is non-blocking when the UART uses
`timeout=0`, so call it frequently from your main loop.

### Inspect connection state

```python
if mesh.config_complete:
    print("connected to", mesh.my_info.my_node_num)
    print("known nodes:", len(mesh.nodes))

for number, info in mesh.nodes.items():
    name = info.user.long_name if info.HasField("user") else "unknown"
    print("!%08x %s" % (number, name))
```

### Use the lightweight protobuf codec

```python
from micromesh import Data, PortNum

message = Data(portnum=PortNum.TEXT_MESSAGE_APP, payload=b"hello")
encoded = message.SerializeToString()
decoded = Data().ParseFromString(encoded)
print(decoded.payload)
```

Generated-module-style imports are available as `micromesh.mesh_pb2` and
`micromesh.portnums_pb2`. A protobuf field named `from` is accessed as `from_` because
`from` is a Python keyword.

## Installation alternatives

Install from a local checkout with MicroPython's package installer:

```sh
mpremote mip install package.json
```

Or copy the package directory manually:

```sh
mpremote fs cp -r micromesh :lib/
```

For CPython development:

```sh
python -m pip install -e .
```

After the first PyPI release:

```sh
python -m pip install micromesh
```

## Supported scope

MicroMesh currently models the most useful portions of the Meshtastic API:

- `ToRadio` / `FromRadio` framing and configuration handshake
- `MeshPacket`, `Data`, `Position`, `User`, and `NodeInfo`
- Device metrics, waypoints, routing, queue status, and log records
- Unknown-field preservation and stream resynchronization

Large configuration, admin, metadata, and module-configuration messages are retained
as encoded bytes rather than fully interpreted.

The protocol definitions come from
[`meshtastic/protobufs`](https://github.com/meshtastic/protobufs).

## Development

Set up the project and run the tests:

```sh
python3 -m venv .venv
source .venv/bin/activate
python -m pip install -e .
python -m unittest discover -s tests
```

The test suite covers encoding, decoding, framing, serial recovery, sending, and
configuration state.

## Releasing to PyPI

Maintainers publish with GitHub Trusted Publishing; no long-lived PyPI token is stored
in the repository. Configure the pending publisher with:

| Setting | Value |
| --- | --- |
| PyPI project | `micromesh` |
| GitHub owner | `pdxlocations` |
| Repository | `micromesh` |
| Workflow | `release.yaml` |
| Environment | `pypi` |

Keep the version in `pyproject.toml`, `package.json`, and `micromesh/__init__.py` in
sync. Publishing a matching GitHub release, such as `v0.1.0`, builds, validates, and
uploads the wheel and source distribution.

## License

MicroMesh is released under the [GNU General Public License v3.0 or later](LICENSE).