UART2MQTT

A minimal Python bridge that connects USB UART devices to MQTT topics. It automatically discovers USB serial devices, filters them using a VID:PID allow list, and creates bidirectional communication between each serial port and its associated MQTT topic.

Features

• Automatically detects serial devices via /dev/serial/by-path
• Filters devices using VID/PID from /sys/class/tty/...
• Bidirectional communication between UART and MQTT
• Dynamic topic generation: <topic_base>/<port>/device_serial_output
• Configurable via a TOML file at /etc/uart2mqtt.toml

Configuration

Create /etc/uart2mqtt.toml:

[mqtt]
host = "mqtt-broker.local"
port = 1883
topic_base = "testbench"


# USB match sections are optional. If specified, it only matches with
# listed vid:pids. Can list [[usb_match]] multiple times, and can use "*" as 
# wilcards.
[[usb_match]]
vid = "1a86"
pid = "7523"

# If no usb_match is specified, all devices are matched similar to this:
[[usb_match]]
vid = "*"
pid = "*"

Usage

Run the bridge:

uart2mqtt

See the example "uart2mqtt.service" example file as well. Update it to include the user this will run as, then:

cp /uart2mqtt.service /etc/systemd/system/uart2mqtt.service
systemctl --now enable uart2mqtt.service

Requirements

• Python 3.11+
• pyserial
• paho-mqtt

Development Setup:

After cloning, install the git pre-commit hooks.

# Run once:
pre-commit install

# To run by hand before a commit
pre-commit run --all-files

License

MIT