BLE mesh packet logging

[sybrenstuvel]

Disclaimer: this PR is indended as a starting point for the feature. The code itself is more a proof of concept, and I'm happy to go over it & clean things up. Let's first look at whether it's a feature that has the project's interest.

This PR adds support for mesh packet logging via a Bluetooth connection.

Adds a wrapper around the Serial.print() calls for MESH_PACKET_LOGGING. The wrapper can either send to serial, as MeshCore does now, or to a BLE client.

The BLE connection doesn't require any PIN, making it easy to connect with meshcore-to-mqtt. I have a matching PR for that too: Cisien/meshcoretomqtt#35

BLE MTU is set to max 256 bytes; the size actually used is also determined by the remote side. The payload will be split into multiple BLE messages when they are longer than the MTU.

For debugging independently of meshcore-to-mqtt, use this script. It uses the bleak package to do BLE.

I've tested this with a Heltec Wireless Tracker, and my meshcoretomqtt branch on a macbook.

#!/usr/bin/env python

import asyncio
from bleak import BleakScanner, BleakClient

NUS_TX = "6e400003-b5a3-f393-e0a9-e50e24dcca9e"
NAME = "repeater-roomserver-name"  # Name of your repeater / room server.


def on_notify(_, data: bytearray):
    print(data.decode("utf-8", errors="replace"), end="")


async def main():
    print(f"Scanning for '{NAME}'...")
    device = await BleakScanner.find_device_by_name(NAME, timeout=10)
    if not device:
        print("Not found")
        return

    async with BleakClient(device) as client:
        print(f"Connected: {client.address}")
        await client.start_notify(NUS_TX, on_notify)
        await asyncio.sleep(3600)  # run for an hour, Ctrl-C to stop


try:
    asyncio.run(main())
except KeyboardInterrupt:
    pass

Disclaimer: this PR was made with the help of Claude AI. I'm a human, though, and happy to personally work on any feedback.