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Meshtastic Python Development

A note to developers of this lib

We use the Visual Studio Code (VScode) default python formatting conventions (autopep8). So if you use that IDE you should be able to use "Format Document" and not generate unrelated diffs. If you use some other editor, please do not change formatting on lines you have not changed yourself.


To build a new release
apt install pandoc
sudo pip3 install markdown pdoc3 webencodings pyparsing twine autopep8 pylint pytest pytest-cov
For development
pip3 install -r requirements.txt


pylint meshtastic


Install and run pytest

  • For more verbosity, add -v or even -vv
pip3 install .
pytest -vv
Run just unit tests
# or (more verbosely)
pytest -m unit
# or
Run just integration tests
pytest -m int
Run the smoke test with only one device connected serially (aka smoke1)
pytest -m smoke1

Running smoke1 will reset values on the device, including the region to 1 (US). Be sure to hit the reset button on the device after the test is completed.

Run the smoke test with only two device connected serially (aka smoke2)
pytest -m smoke2
Run the wifi smoke test
pytest -m smokewifi
Run a specific test
pytest -msmoke1 meshtastic/tests/

# or to run a specific smoke2 test
pytest -m smoke2 meshtastic/tests/

# or to run a specific smoke_wifi test
pytest -m smokewifi meshtastic/tests/

Add another classification of tests such as unit or smoke1

See pytest.ini.

To see the unit test code coverage
pytest --cov=meshtastic
# or if want html coverage report
pytest --cov-report html --cov=meshtastic
# or
make cov
To see slowest unit tests, you can run
pytest --durations=0
# or
make slow

Wire encoding

When sending protobuf packets over serial or TCP each packet is preceded by uint32 sent in network byte order (big endian). The upper 16 bits must be 0x94C3. The lower 16 bits are packet length (this encoding gives room to eventually allow quite large packets).

Implementations validate length against the maximum possible size of a BLE packet (our lowest common denominator) of 512 bytes. If the length provided is larger than that we assume the packet is corrupted and begin again looking for 0x4403 framing.

The packets flowing towards the device are ToRadio protobufs, the packets flowing from the device are FromRadio protobufs. The 0x94C3 marker can be used as framing to (eventually) resync if packets are corrupted over the wire.

Note: the 0x94C3 framing was chosen to prevent confusion with the 7 bit ascii character set. It also doesn't collide with any valid utf8 encoding. This makes it a bit easier to start a device outputting regular debug output on its serial port and then only after it has received a valid packet from the PC, turn off unencoded debug printing and switch to this packet encoding.