lqml/examples/meshtastic

Info

Please note: this is WIP!

Currently it can be used to send direct messages between any number of radios.

It's basically meant to be used in an emergency situation, where internet is not available, in order to communicate with simple text messages. This kind of mesh network is limited to about 70 nodes/radios/users to remain reliable.

Technical notes

This app uses both BLE (bluetooth low energy) and the protobufs serialization library version 3.

For BLE you need to build the plugin in cpp/ first (written in Qt5).

The cl-protobufs library is included here because the official version doesn't work without the C++ plugin installed (which we don't need here). So I made some small adaptions and included all generated proto Lisp files in order to be independent.

Unfortunately cl-protobufs loads very slowly on mobile (and conses hugely during startup). On an older phone and a cold startup this may take more than 20 seconds. On newer phones and warm startup it should 'only' take around 10 seconds (which seems acceptable).

For the above reason, an animation is shown while loading the app, together with a counter. For this to work, the app is loaded in the background (that is, in a separate thread). You'll need to rebuild the lqml library for this to work.

You will see a json output of all data sent/received. It simply uses the print-json convenience function from cl-protobufs.

The message db uses sqlite, but in a lispy manner, storing basically just a plist for every message.

The reason I chose Qt qsqlite over cl-sqlite is mobile: Qt comes with its own version, which is pulled in automatically, so one doesn't need to care about the OS limitations or indirect requirements. Additionally, cffi (as a dependency of cl-sqlite) currently needs a small hack to even work on mobile.

Tested

Tested on Linux, macOS, android, iOS. The macOS version shows an ECL exception during BLE ini, but works nevertheless.

It should also work on Windows >= 10, but this is not tested yet.

Since this is WIP, it may currently not work on all platforms (e.g. mobile).

How to use cl-meshtastic

Your radio needs to be turned on and bluetooth needs to be enabled before you start the app.

On android coarse location permission is required for BLE to work.

Pairing of your LoRa radios is generally not needed beforehand, the app will ask for pairing/PIN during BLE ini. If your device doesn't have a display, use 123456 as your PIN.

It may occur that the devices are sometimes not found; in those cases

• try to turn bluetooth off and on again, and/or:
• try to reboot your radios, and/or:
• try to unpair your radios from all computers/devices

A generic bluetooth app like nRF Connect may help in order to see if the devices themselves work and are able to connect.

See also readme-usage.

Run

lqml run.lisp

Optionally pass -slime to start a Swank server, and connect from Emacs with M-x slime-connect.

During development you can pass -auto, which will reload all QML files after you made a change to any of them and saved it. For re-initialization after reloading, file lisp/qml-reload/on-reloaded will be loaded.

Closing the window quits the app. If you try to kill it with ctrl-c, you need an additional ctrl-d to exit from ECL. To quit from Slime, do (qq) which is short for (qquit).