From Wikipedia:

MeshCore is an open-source mesh networking protocol and software platform designed for off-grid, low-power text communication using LoRa (Long Range) radio technology. The system enables decentralized, multi-hop wireless messaging without reliance on cellular networks or internet infrastructure.

Use cases include emergency and disaster communications, outdoor and remote activities, [...] and experimental and educational deployments of low-power mesh networking.

[It] is designed to [...] operate in unlicensed ISM frequency bands such as 868 MHz and 915 MHz, depending on regional regulations.

The idea is that each person has a small companion device C paired to their cellphone via Bluetooth, and via that device, they can text each other or post public messages using the 915 MHz band, all without a special license. The signal can travel directly between companion devices if they are close enough, or via a series of repeaters R to extend coverage.

• The MeshCore app downloaded to your cellphone or computer.
• A device with the MeshCore companion firmware paired to your cellphone.
• If needed, a device with the MeshCore repeater firmware to extend messaging range.

Each person who wants to send messages needs their own companion device.

• Search for “MeshCore” by “Liam Cottle” on Google Play or the Apple App Store.
• Alternatively, an offline copy can be downloaded for Android, Windows, macOS, Linux, and Web from https://meshcore.io. It's a good idea to have an offline copy in case of emergency.

• Recommended devices are listed at https://meshcore.io
• Alternatively, supported devices listed on https://meshcore.io/flasher can be purchased online from overseas suppliers such as AliExpress or Seeed Studio, or in Canada from Robot Shop.

If you already have MeshCore installed, back up your current settings:

• Open the MeshCore app
• Navigate to the Settings (the gear in the top right corner)
• Scroll down to the “Extra Tools” section and select “Export Config”
• “Select All” and click the check mark in the top right corner to save the “.json” file to your phone.

Flash the MeshCore Firmware:

• Connect the companion device to your computer via USB.
• Go to https://meshcore.io/flasher (using a Chromium Browser).
• Select your device.
• Select Companion Bluetooth.
• Select Enter DFU Mode.
• Select Erase Flash (for brand new devices only).
• Select Flash.

To reload your previous config file (required only if you lost your configuration for some reason).

• Open the MeshCore App.
• Connect to the companion device, but it probably has a different Bluetooth name now.
• Enter the PIN displayed on your MeshCore device’s screen. If your device doesn’t have a screen, the default PIN is “123456”.
• Skip Setup.
• Navigate to the Settings (the gear in the top right corner).
• Scroll down to the “Extra Tools” section and select “Import Config”.
• Click on “Select File”.
• Select the “*.json” file.
• “Select All” and click the check mark in the top right corner.

• Turn on your device.
• Open the MeshCore App.
• Tap the “Connect” button in the top right corner.
• Tap the “MeshCore-XXXX” device that matches the name shown on your MeshCore device’s screen.
• Enter the PIN displayed on your MeshCore device’s screen. If your device doesn’t have a screen, the default PIN is “123456”.
• Once pairing is successful, you’ll be taken to the main screen.

If you’re having trouble pairing with Bluetooth, try rebooting your phone.

The device name in Bluetooth will not update until you reboot your node.

This page shows nodes with duplicate addresses, which can be fixed by increasing the path hash size.

• Tap the “Default Path Hash Size” and select “2-byte” for companions, or “3-byte” for repeaters.
• Tap the ✔ icon in the top right corner to save the settings.

Finally, let's tap the ✔ icon in the top right corner one last time to save the settings before exiting.

There was a deliberate decision made to prevent auto advert for companions (but not for repeaters). As such, you should flood advert at least once a week so that new users can find and add you to their contact list.

• Tap the “wave” icon just to the left of the gears at the top
• Tap “Advert • Flood Routed”

The easiest way to add nodes that are in your neighbourhood to your contact list is to use the map feature. However, there are three different kinds of maps in MeshCore:

To populate your contact list, use the map under “Discover Contacts”. You might have to leave your node on for a bit for it to hear all the nodes in your area since they need to advert or transmit for your node to see them:

• In the “Discover Contacts” → “Map View”
• Tap on the filter icon and select “Users”.
• Tap on this ⋮ in the top right and uncheck “Show Added Contacts”

The map will only show users that have not been added yet. To add them:

• Tap on a node
• Under the node's name, tap on “Add”

If you go back to the main page's “Map” (1), you should now see that contact.

The maps only show nodes that have shared their Position in Advert. Nodes that have not shared their location will still show in the list, but you won't be able to tell where they are located. That's why it's important to share your approximate location: so others in your neighbourhood can add you to their contact list.

The fastest way to share your contact information with someone next to you is to use QR Codes. However, don't text or email these out; for that, there's a better way...

The easiest way to share your contacts via email or SMS is to use a contact link.

We haven't discussed Channels yet, so feel free to come back to this section later.

There are basically two different strategies for encrypting a message:

Symmetric-key cryptography is a system where the key to encrypt and decrypt a message is the same.

For example, if I generate a long random list of numbers between 1 and 26, I could use that to encrypt a message, and you could use the same list to decrypt it. Let's encrypt the word “hello” by shifting each letter by (1, 9, 2, 7, 3). The result is “innsr”. You can then shift them back using the key to recover “hello”.

This can be very secure if the key is random, is as long as the message itself, and is never reused for other messages. A big practical problem is that I have to somehow give you a copy of the key without it getting intercepted. If I can do that, I might as well give you the unencrypted message.

Public-key cryptography bypasses the problem of sharing the key securely.

You start with a large random number and use that to generate a pair of keys that are “inverses” of each other in some sense. That way, a message encrypted with one key can only be decrypted with its pair. This is based on the idea that a lot of processes in math are not easily reversible, so deducing one key from its pair is almost impossible.

Once you have this pair of keys, you keep one secret, and you publish the other one. That's right, you share one of your keys with everyone! Here are two things that you can now do:

• If I use your public key to encrypt a message that I post on a public forum, you're the only one who will be able to decrypt it with your private key.
• If I use my private key to encrypt a message that I post on a public forum, everyone will be able to decrypt the message (because they have my public key), but they'll know that the message has not been tampered with, and that it really comes from me because I'm the only one with the private key that encrypted it. Most software publishers use this scheme to sign the programs they publish online.

MeshCore uses Public Key Cryptography to:

• Identify you uniquely: your public key is your unique ID. It's listed in System -> Public Info, and it's part of the Contact Info that you share with others for them to add you to their contact list. Your private key can be exported for backup purposes or in case you upgrade your device and want to keep the same ID. But don't share your private key with anyone.
• A private message is encrypted with the recipient's public key. So even though it's transmitted over RF and everyone is receiving the message, only the recipient's private key can decrypt it.
• Different types of channels use public/private key pairs in different ways to make the channel either public or private (more on that in the next section).

To send a direct, private message to someone, you both need to be in each other's contact lists.

• Use one of the four methods for sharing contact info.
• From the “Contacts” screen, tap on a contact.
• Type your message as you would an SMS.

When you send a direct message to someone, it’s possible that it may not go through after several automatic attempts. This can happen for many different reasons, such as:

• Being out of range of the intended recipient.
• There are no repeaters in between you and the intended recipient.
• The intended recipient’s radio might be turned off.
• There might be interference on the radio spectrum.
• The recipient doesn't have you in their contact list.

To try sending the failed message again:

• Long-press the failed message shown in red.
• Tap the “Retry Sending” button shown in the message actions pop-up.
• Your message will try sending again.

Channels are “places” for people to share messages with groups of people. It's not possible to know who did and did not receive messages posted in channels. There is also no “storing” capability, so if someone's node is out of reach, they will miss these messages.

There are three types of channels:

By default, messages sent to the “Public” channel can be seen by anyone on the MeshCore network. They are repeated across the mesh by all repeaters that hear them. Other mesh nodes in range of you or a repeater that rebroadcast the message should receive it.

To send a message:

• Tap the channels tab at the bottom of the screen.
• Tap the “Public” channel.
• Type a message and press the send icon.

To join the “Public” channel if it's not there:

• Tap on ⋮ in the top right.
• Tap on “Add Channel”
• Tap on “Join the Public Channel”
• Leave the Channel Name as “Public” and tap “Join Channel”

Hashtag channels are public channels based on topics or regions. Here are a few channels used in the South West region of BC:

To join an existing hashtag channel, or create a new one:

• Tap on ⋮ in the top right.
• Tap on “Add Channel”
• Tap on “Join a Hashtag Channel”
• Type the channel name after the # symbol and tap “Join Channel”

Private channels create their key pairs randomly and independently of the channel name. As such, a private channel can be renamed without affecting its “identity”. Here are a list of some private channels used in the South West region of BC.

There may be more that we are not aware of, and we will not list the private keys for these channels here.

To join an existing private channel:

• Obtain the private key from someone in that channel.
• Tap on ⋮ in the top right.
• Tap on “Add Channel”
• Tap on “Join a Private Channel”
• Type the channel name, the secret key (private key), and tap “Join Channel”

To create a new private channel:

• Obtain the private key from someone in that channel.
• Tap on ⋮ in the top right.
• Tap on “Add Channel”
• Tap on “Create a Private Channel”
• Type the channel name and copy the secret key (you can do this later).

Each channel can be configured with one of three different notification levels:

To change a channel's default notification settings:

• Tap on ⋮ beside the channel you want to change.
• Tap on “Notifications”
• Select the notification level you want
• Tap the ✔ icon to save the settings.

There are two ways to mention someone in a channel:

• Long-press on one of their messages.
• Tap “Reply”
• Type your message after the string that's automatically added.

or

• In the message window, type: “@[TheirMeshCoreName]” somewhere in the message (it doesn't have to be at the beginning).

To check the signal strength to and from a nearby repeater, you can run a ping test:

• Tap on this ⋮ icon next to a repeater contact.
• Tap the “Ping (Zero Hop)” menu item.
• A green pop-up will show signal strengths if successful.
• A red pop-up will show “Timeout” if your companion didn’t hear the repeater.

Ping tests do not hop through multiple repeaters. You must be in range of the specific repeater you are ping testing. For a ping test to be successful, the repeater must hear your companion signal directly, and your companion must hear the repeater signal directly. If you’re not in range of the repeater, the ping test will fail with a timeout error.

This document is licensed under CC BY-SA 4.0 International. The original can be found at https://scarcs/links/meshcore/home

A big part of this document used Liam Cottle's MeshCore Quick Start Guide from November 2025 (CC-BY-SA) as a starting point. We then updated and expanded his guide with regional settings used on the South West Coast of BC.