Getting started with Meshcore¶

There are two ways of configuring a Meshcore device:

a companion: this a "client" to the mesh, that needs a repeater to relay messages, but that is the primary interface to send and receive messages
a repeater: this is the "relay" in the mesh, which transmits messages between clients and repeaters and other clients and repeaters

If you're just getting started, try a Companion, and we'll assume you're configuring a Companion for the rest of this guide, unless otherwise noted.

Warning

Some Meshcore configurations exposes your location by default on devices which have a GPS device! To work around this problem, you can disable the GPS or reduce the coordinates precision, we recommend two digits (~1km) for clients and 3 digits (~100m) for repeaters.

Hardware¶

Pick a device in our hardware review notes or the official hardware list.

It's cheap! Expect to pay 50$CAD for a starter kit, 150$CAD for a decent solar relay.

Tip

If the device you picked comes with a removable antenna, make sure you connect the antenna before powering up the device. A radio that transmits without an antenna can damage itself!

Software¶

Now you own a LoRa transceiver, congratulations! The next step is to make sure it runs Meshcore by installing firmware on it, and that you can talk to the device, typically by installing an app on your phone.

Backing up before flashing¶

If you're flashing an already configured device, you should backup before flashing it.

On the Meshcore you want to:

go into Settings (the "gear" icon)
go into Export Config
hit Select All
hit the check mark
save the file somewhere safe

Normally, flashing a Meshcore device with a newer version should be safe and your settings should be kept, but it's always good to backup your configuration anyways, and this can be used to copy your configuration to another device as well.

On Meshtastic, this can be done by exporting the configuration in the Meshtastic app settings, or with the Meshtastic command line tool:

meshtastic --export-config > devicename.yaml

Flash the firmware on the device¶

First you need to flash your device, which essentially means connecting to the following website.

https://flasher.meshcore.io

Your web browser must support the Web Serial API, which includes Chrome (and derivatives) and Firefox 151 or later.

You may skip this step if it comes flashed with Meshcore already.

Important

This is the moment when you pick between Companion and Repeater, and you can't go back without reflashing!

You will also have the option to flash a "Bluetooth" of "Serial" companion. You should typically choose "Bluetooth" unless you want to connect to the device over the USB cable. Those are exclusive: a Bluetooth device cannot be accessed over serial and vice-versa.

Proprietary software warning

While most Meshcore firmware is free software (the meshcore-dev/MeshCore repository, the T-Deck firmware is proprietary. Awesome MeshCore lists a few alternatives.

Connect your device to your computer using a USB cable. Note that for some USB-C cables, you might need to flip the cable over for the connection to work. A good hint is whether the device is charging or not from your laptop: if it isn't, it means it likely isn't connected correctly.

On many devices, you need to enter some special mode for flashing to work. Here are examples:

Heltec: hold the "program" (PRG) button while connecting the USB cable. For the Heltec v4, it will show up as a JTAG device. On the Heltec v3, it will show up as a CP2102 USB to UART Bridge Controller.
RAK: double-click the reset button will bring it in "DFU" mode, but the web flasher should also be able to do that automatically.

Bug

We have had trouble flashing RAK4631 device. You can:

download the U2F file
put the device in "DFU" mode
mount it
copy the file on the disk
unmount

This can also be done automatically with this reflashtic command:

reflashtic.py --pmount -i RAK_4631_companion_radio_ble-v1.15.0-dee3e26.uf2

The adafruit-nrfutil command can also apparently be used for this.

During first boot, the device will display the message:

Loading...

... for a solid minute, that is normal.

Repeater configuration¶

If you are configuring a repeater, this is also the step where you configure the repeater through the web interface. Some settings can be performed over Bluetooth later.

You need to at least:

set a name to the router: the local convention is to use a YUL- prefix and the general location of the router, e.g. YUL-Villeray or YUL-Parc-Extension
set an admin password and save it to your password manager for remote administration

The remaining settings can be done over Bluetooth from a companion, which we'll assume below.

Tip

Many settings can be done over a serial port, if you're an advanced user. You can connect to the serial port on Linux with tio:

tio /dev/ttyUSB0

Then the above commands are:

set name YUL-Villeray

You can also connect to your devices with the meschore-cli program. The full command line reference is available in the upstream documentation.

Flashing an observer¶

If you want to setup an "observer", you should head over to the observer.gessaman.com flasher and flash that firmware instead. It will flash a custom firmware that automatically connects to WiFi and MQTT to relay packet data.

You should not flash an observer if there is already one in your local area. As a rule of thumb, if you're multiple hops from the nearest observer, or it's far enough that it doesn't see your traffic, it's a good idea to set one up. Otherwise, we might not need your observer!

You can setup the observer as a Room Server if you want one of those in your area, but similarly, we might not need one of those if there is already one around.

In any case, it's likely not necessary to setup the observer as a "repeater" unless it's the only repeater in your area. In that case, either set it up as a room server or as a repeater with repeat turned off. This will help reduce the noise on the mesh.

Boot loader OTA fix¶

Advanced users only

This section is a little more advanced and not required for beginners.

You might want to flash upgrades "over the air" (OTA) if your device is in a hard to reach location. There are problems with built-in boot loaders for this, so it is recommended to flash this alternative boot loader.

For that, you need to flash a custom boot loader, before you install the device in the remote location:

find and download the right device file in the last release of the release list, which should end in a .uf2, for example in the current release the SenseCAP Solar P1 file is the update-sensecap_solar_p1_bootloader-0.9.2-OTAFIX2.2-BP1.3_nosd.uf2
connect the device to your computer over USB
put the device in DFU mode, which typically involves double-clicking on the reset button (clicking twice within 500ms)
mount the device that appears
copy the .uf2 file to the device

This should take only a short time and reboot the device.

OTA upgrades¶

Advanced users only

Over-the-air (OTA) upgrades are risky and should be used only if remote access is inconvenient, or if you have a secondary device to run a first test run on.

Beginners shouldn't need to follow those instructions.

You should also not do your initial flash over the air, it's not worth it!

Only use this for upgrades and only if you performed the above Bootloader OTA fix!

Once your device is correctly flashed for OTA (over the air) upgrades, you should be able to perform upgrades remotely, by following this official guide or the Ottawa Mesh guide. A few tips:

if you have a custom Android firmware, you might not have access to the App store and the nRF Device Firmware Update app. You can add this GitHub repository to Obtainium instead, which works fine.
you must change the settings in the app before flashing the upgrade, if you get a timeout, it's because the settings are wrong.
flashing over Bluetooth is slow, we're seeing 3KB/s transfer speeds

Here is a full procedure, but see the official or Ottawa mesh guide if it fails (and let us know):

install the nRF Device Firmware Update app (source code which can be installed through Obtainium)
configure the right settings in the app which is called DFU:
- Packet receipts notification - ON
- Number of packets - 8
- Request high MTU (Android only) - OFF
- Disable resume - ON
- Prepare object delay - 0 ms
- Force scanning - ON
Leave the other settings untouched.
download the right firmware for your device in the Meshcore web flasher interface, make sure you pick the .zip file!
connect to the device command-line, which should be accessible over the LoRa management interface
type the following magic command:
```
start ota
```
This will show the Bluetooth MAC address of your device, which can be used to identify it below.
back in the app, start the update, by tapping Select and picking the .zip file you downloaded earlier
select the device which should show up as something like SENSECAP_SOLAR_OTA and also show the MAC address above
press start

This will go through various steps. If you have messed up the settings, it will like timeout at the DFU initialized step. Otherwise it should show a progress bar and transfer rate after that.
you're done!

Install an app¶

Unless you picked a standalone device, now you'll need something to talk with people on the mesh. Unless you use a standalone device, this means installing software on your phone.

You can try that from your computer with a web browser by using Liam Cottle's web app. There are also iOS and Android versions and a pretty good Linux desktop app called Meshy.

Proprietary software warning

The official Meshcore app is proprietary software that do not publish their source code and require a subscription or a 10 second wait time for certain features.

You can work around some of those problems by installin the open app which requires going through Obtainium on Android or test flight. It's a little complicated, so don't venture there unless you get frustrated with the official apps. The open app also lacks a few features from the official one, namely:

To connect your phone to the device, you need to find the right device in your list, which can be challenging if you are in an environment with lots of Bluetooth devices.

Pick the device name that looks like the alphanumeric identifier displayed at the top left of the display.

The Bluetooth PIN should also be displayed, bigger, and in the center, as a string of 6 digits. That is different from the device name, which will have letters in it, and is only used in pairing.

The device name on the top left, however, identifies the device over the airwaves, both on the Mesh and Bluetooth.

Configuration¶

The main configuration you need to do on the device is set the preset, but you should also pick a display name.

Radio settings: "recommended USA / Canada"
Display name: your name, YUL-Area for a repeater, for example YUL-Villeray, YUL-Parc-Extension, etc
Region: do not set a region, as we currently do not use one, and it will interfere with routing

The "recommended USA / Canada" preset is, at the time of writing, the following settings:

Frequency: 910.525 MHz
Bandwidth: 62.5 kHz
Spreading Factor (SF): 7 or SF7
Coding Rate (CR): 5 or CR5

But you shouldn't need to write those down by hands, generally. Just pick the recommended preset.

Tip

You can also perform this configuration over the command line:

set freq 910.525
set bw 62.5
set sf 7
set cr 5
set name YUL-Area

Repeaters can lose track of time¶

Repeaters can lose their time after reboot.

Make sure the repeater has an accurate clock. Companion apps can be configured to automatically sync the clock on login to workaround this issue.

Repeaters without an accurate clock route packets properly, but its adverts will be ignored until its time is accurate.

Enabling the GPS on a device can keep the clock in sync at the cost of a lower battery life.

Multi-byte repeater configuration¶

On a repeater, you should also configure the router identifier for multi-byte path routing, specifically for three bytes, which is called "mode 2". For this, you need to enter the "command line" mode and enter the command:

set path.hash.mode 2

You can confirm the current mode with:

get path.hash.mode

And some relays require a reboot for the change to take effect:

reboot

Others have reported having to do the change twice for it to take effect as well.

Observer configuration¶

Assuming you flashed your device with the observer.gessaman.com flasher above, you need to do extra configuration here:

as above, setup the preset:
```
set radio 910.525,62.5,7,5
```
if setup as a repeater and you already have one of those, turn off repeat:
```
set repeat off
```

setup the right MQTT servers:

set mqtt1.preset meshcore-ca-1
set mqtt2.preset meshcore-ca-2
set mqtt.iata YUL

setup WiFi credentials:

set wifi.ssid YourWiFiNetwork
set wifi.pwd YourWiFiPassword

reboot:
```
reboot
```

You made it! Say hi!¶

At this point, your companion should be properly configured. Repeaters require a little more work, below.

Introduce yourself! Say "hi!" on the "Public" channel. Explain what device did you setup, where's your general area, what's the weather like, etc. Be kind, reply to people, participate!

Channels¶

If you want to go a little further, you should know that Meshcore supports the concept of "channels" which are essentially different communities separated by their own private keys.

Many of those are "public", in the sense that the encryption key is derived from an easy to guess name, like #testing, so those are not "really" encrypted.

But you can use channels to really create your own secret communication channels. Contents will be encrypted as long as the channel name remains secret, but who is talking to who, the number of messages sent will be visible to an attacker.

Public channels¶

We know about the follow channels currently in use¹:

Name	Hex Key	Base64	Purpose
Public	`8b3387e9c5cdea6ac9e5edbaa115cd72`	`izOH6cXN6mrJ5e26oRXNcg==`	General conversations
`#testing`	`cde5e82cf515647dcb547a79a4f065d1`	`zeXoLPUVZH3LVHp5pPBl0Q==`	Should be used for tests
`#wardriving`	`e3c26491e9cd321e3a6be50d57d54acf`	`48JkkenNMh46a+UNV9VKzw==`	Used by Meshmapper pings
`#habs`	`e570409412b40c123b4ab787351ab30b`	`5XBAlBK0DBI7SreHNRqzCw==`	Far from real time game updates and gossip
`#bots`	`0d24f5830b449668b8c221759b6c50d2`	`DST1gwtElmi4wiF1m2xQ0g==`	Where to run bots, a bot replies to `test` and `ping`there
`#ceuxquimarchemoyen`	`751be125eb7d167e07a95603c9e9a5dd`	`dRvhJet9Fn4HqVYDyeml3Q==`	Another test channel for people who have trouble

You should generally not need the hex and Base64 keys. They are only provided here as a reference for some rate situations where you need to enter the secret key directly. For example, some standalone firmware like the T-Deck might require this although you might get away with popping up the menu to select the Enter # option.

Other channels¶

See also the channels used in other communities:

References¶

Those hashes were generated with the one-liner:

python -c 'import base64; import hashlib; import sys; bytes = hashlib.sha256(sys.argv[1].encode("utf-8")).digest()[:16]; print(bytes.hex(), base64.b64encode(bytes).decode("utf-8"))' '#testing'

A more readable version is available as hashchan.py. ↩