Setting Up the Client

Pair node 2 with the MeshCore phone app over Bluetooth and match its radio settings

Node 2 has companion firmware on it. It has no keyboard and no way to type a message - that is your phone’s job. Let’s pair them up.

Getting the app

The MeshCore companion apps are built by Liam Cottle and are available for iOS, Android, Windows and macOS. Search your app store for MeshCore, or grab them from files.liamcottle.net/MeshCore.

The app is free. There is an optional in-app purchase that removes a wait timer on remote server management, which becomes relevant in lesson 13 - you do not need it yet.

No phone? If you flashed Companion (USB Serial) instead of BLE, plug the board into a computer and open app.meshcore.nz in Chrome or Edge. It is free, open source, and does the same job over USB.

Pairing over Bluetooth

1. Power up node 2 with its antenna fitted. The OLED should show a pairing screen or the node’s name
2. Open the MeshCore app and choose to add or connect a device
3. Pick your node from the Bluetooth list - it will have a generic name like MeshCore-a1b2 to begin with
4. If a pairing code is requested, the default is usually 123456, and the OLED will show a code if one is generated
5. The app connects and shows you the node’s status

A note on Bluetooth: BLE range is a few metres. The board needs to be near your phone - it is a radio modem for your phone, not something you leave in the loft. The long range part happens on the LoRa side.

Naming your node

In the app’s settings, set your node’s name. This is what other people in the mesh will see.

Pick something you are happy being public. Kev-Handheld is good. Your full name and postcode is not.

Matching the radio settings

This is the step that decides whether the whole project works.

1. Go into the app’s settings for the connected node
2. Find the frequency or radio section
3. Look for a preset menu - usually a three-dot icon next to the frequency field
4. Choose EU/UK (Narrow)
5. Apply, and confirm

Verify the four numbers against what your repeater reported when you ran get radio in lesson 7:

If these do not match your repeater exactly, nothing that follows will work. It is worth double checking now rather than debugging later.

Send an advert

With the settings applied, tell the mesh you exist. In the app there will be an option to advertise or send advert - often on the node’s status screen or in a menu.

You have two choices:

• Zero-hop advert - heard by anything in direct radio range, including your repeater
• Flood advert - passed on across the whole mesh

Start with a zero-hop advert. If your repeater is on the desk next to you, that is all you need.

Why this matters: Unlike repeaters, client nodes do not advertise automatically on a timer. Nobody knows you exist until you tell them. If you have set everything up correctly and your contact list is empty, sending an advert is usually the missing step.

Battery and power

The companion node is the one you carry, so power matters:

• USB-C from a power bank is the simplest option
• A LiPo on the SH1.25 connector makes it properly portable
• The OLED is a meaningful power draw - some builds let you dim or blank it

Try it Yourself

1. Pair the app, rename the node, and confirm the new name appears on the OLED.
2. Send a zero-hop advert, then walk 20 metres away and send another. Does the repeater still hear you?
3. Challenge: unpair and re-pair the node. Getting comfortable with this saves panic later when the app forgets a device.

Common Issues

Problem: The node does not appear in the Bluetooth list.

Solution: Confirm you flashed Companion (BLE) and not Companion (USB Serial) or Repeater.

Why: Only the BLE build advertises over Bluetooth. Repeater firmware has no BLE interface at all.

Problem: The app connects, then immediately disconnects.

Solution: Forget the device in your phone’s Bluetooth settings, then pair again from inside the MeshCore app.

Why: Pairing at the OS level rather than in the app confuses the connection state on some phones.

Problem: Everything looks fine but my contact list is empty.

Solution: Send an advert, and get someone else to send one too.

Why: Contacts are learned from adverts. A silent mesh looks identical to a broken one.

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