This library provides UDP-based broadcasting of Meshtastic-compatible packets.

Installation

pip install mudp

Command Line

To view all Meshtastic udp activity on your LAN:

mudp

mudp accepts the Meshtastic 1-byte PSK aliases AQ==, Ag==, Aw==, BA==, BQ==, Bg==, and Bw== anywhere a channel key is used and normalizes them internally.

If multicast binding needs tuning, set MUDP_BIND_MODE to auto, group, or any. auto prefers binding to the multicast group first on Linux, then falls back to 0.0.0.0.

PubSub RX Topics

When using this library as a listener, it can publish received packets to the Python pubsub system. The following topics are available:

• mesh.rx.raw – publishes (data, addr) with the raw UDP packet bytes and source address tuple.
• mesh.rx.decode_error – publishes (addr) when a packet fails to decode.
• mesh.rx.packet – publishes (packet, addr) for all successfully parsed MeshPacket objects, including duplicates.
• mesh.rx.unique_packet – publishes (packet, addr) only for the first copy of a packet seen by the listener.
• mesh.rx.duplicate – publishes (packet, addr) when the listener sees the same (from, id) again.
• mesh.rx.decoded – publishes (packet, portnum, addr) when the decoded portion is available for a unique packet.
• mesh.rx.port.<portnum> – publishes (packet, addr) for filtering unique packets by port number.
• mesh.rx.text – publishes (packet, addr) for unique decoded TEXT_MESSAGE_APP packets.
• mesh.rx.routing – publishes (packet, routing, addr) for unique decoded ROUTING_APP packets.
• mesh.rx.ack – publishes (packet, routing, addr, pending) for unique routing ACKs and clears any matching pending outbound ACK state.
• mesh.rx.nak – publishes (packet, routing, addr, pending) for unique routing NAKs and clears any matching pending outbound ACK state.

Use mesh.rx.packet when you need every wire observation. Use mesh.rx.unique_packet and the decoded/per-port/text/routing topics for application logic that should run once per logical message.

UDPPacketStream also accepts dedupe_ttl_sec and dedupe_max_entries to tune how long (from, id) observations stay in the duplicate-suppression cache and how large that cache can grow.

Reliability Topics

When sending direct packets with want_ack=True, mudp tracks pending ACK state and retransmits the original serialized packet if no ACK or NAK is received.

• mesh.tx.retry – publishes (pending) when a tracked outbound packet is retransmitted.
• mesh.tx.retry_error – publishes (pending, error) if a retransmit send attempt fails locally.
• mesh.tx.max_retransmit – publishes (pending, error_reason) when retry attempts are exhausted.

Current behavior:

• direct want_ack packets are retried
• broadcast packets are not retried
• ACK and NAK handling uses ROUTING_APP packets
• duplicate classification happens at the listener level using a TTL-backed (from, id) cache

Send Functions (see examples for further information):

from mudp import (
    conn,
    node,
    send_nodeinfo,
    send_reply,
    send_text_message,
    send_device_telemetry,
    send_position,
    send_environment_metrics,
    send_power_metrics,
    send_health_metrics,
    send_waypoint,
    send_data,
)

# meshtastic <2.8
# MCAST_GRP = "224.0.0.69"
MCAST_GRP = "239.0.0.69"
MCAST_PORT = 4403

node.node_id = "!deadbeef"
node.long_name = "UDP Test"
node.short_name = "UDP"
node.channel = "LongFast"
node.key = "1PG7OiApB1nwvP+rz05pAQ=="
conn.setup_multicast(MCAST_GRP, MCAST_PORT)

send_text_message("text", keys=values...)
send_reply("text", packet.id, keys=values...)
send_reply("👍", packet.id, emoji=True, keys=values...)
send_nodeinfo(keys=values...)
send_device_telemetry(keys=values...)
send_position(latitude, longitude, keys=values...)
send_environment_metrics(keys=values...)
send_power_metrics(keys=values...)
send_health_metrics(keys=values...)
send_waypoint(latitude, longitude, keys=values...)
send_data(destination_id, payload, portnum=256, want_ack=False)

Optional Arguments for all message types:

- to=INT
- hop_limit=INT
- hop_start=INT
- want_ack=BOOL
- want_response=BOOL

Example:
```python
send_text_message("Happy New Year", to=12345678, hop_limit=5)
send_reply("👍", reply_id=packet.id, emoji=True)
send_reply("message received", reply_id=packet.id)
send_data("!deadbeef", b"raw bytes here", portnum=256, want_ack=True)

Use emoji=True when the reply payload is an emoji reaction. Plain-text replies only need reply_id.

Supported keyword arguments for nodeinfo:

• node_id
• long_name
• short_name
• hw_model
• is_licensed
• role
• public_key

Supported keyword arguments for device metrics:

• battery_level
• voltage
• channel_utilization
• air_util_tx
• uptime_seconds

Supported keyword arguments for position metrics:

• latitude (required)
• longitude (required)
• latitude_i
• longitude_i
• altitude
• precision_bits
• HDOP
• PDOP
• VDOP
• altitude_geoidal_separation
• altitude_hae
• altitude_source
• fix_quality
• fix_type
• gps_accuracy
• ground_speed
• ground_track
• next_update
• sats_in_view
• sensor_id
• seq_number
• timestamp
• timestamp_millis_adjust

Supported keyword arguments for environment metrics:

• temperature
• relative_humidity
• barometric_pressure
• gas_resistance
• voltage
• current
• iaq
• distance
• ir_lux
• lux
• radiation
• rainfall_1h
• rainfall_24h
• soil_moisture
• soil_temperature
• uv_lux
• weight
• white_lux
• wind_direction
• wind_gust
• wind_lull
• wind_speed

Supported keyword arguments for power metrics:

• ch1_voltage
• ch1_current
• ch2_voltage
• ch2_current
• ch3_voltage
• ch3_current

Supported keyword arguments for health metrics:

• heart_bpm
• spO2
• temperature

Supported keyword arguments for waypoints:

• id
• latitude
• longitude
• expire
• locked_to
• name
• description
• icon

Install in development (editable) mode:

python3 -m venv .venv
source .venv/bin/activate
pip install -e .