Three Nodes on the Air

You have two LoRa boards. They arrived this week, you’ve read enough to know what MeshCore does, and now you want to see packets move. This post is the LoRa mesh network setup tutorial that gets you to a working three-node mesh — one you can feel confident about, not just hope is working.

The whole process takes less than an hour.

What you need

Hardware: Two LoRa boards to start, three if you want to test a relay hop. Any supported board works — Heltec V3, RAK WisBlock 4631, LilyGo T-Beam, or Wio Tracker L1 Pro. The boards don’t need to match. A USB-C cable and a phone or computer to run the companion app.

Firmware: No toolchain. Use meshcore.io/flasher in Chrome or Edge. It runs entirely in the browser and directly flashes the board over USB.

App: The MeshCore companion app for Android, iOS, or the web app at app.meshcore.nz.

Step 1: Flash both boards

Connect each board one at a time. Open meshcore.io/flasher, select your board model, and choose Companion firmware. Flash. Repeat for the second board.

If you’re flashing a third board for a Repeater, return to the flasher and select Repeater firmware for that one. The hardware is identical; the firmware role is what determines behavior.

Firmware version doesn’t need to match between boards for basic operation, but keeping them on the same release reduces variables when you’re troubleshooting. You can check the version from each board’s serial output or via the companion app’s node info screen.

Step 2: Configure name and radio settings

For Companion nodes: pair the board to your phone via Bluetooth and open the app. Set a node name — something you’ll recognize — and verify the radio frequency matches your region. In the US, this is 915 MHz. Boards shipped for the US are pre-configured for 915 MHz, but confirm it.

For a Repeater: connect via USB and open config.meshcore.io in a browser to set the node name and verify frequency. Repeaters are configured via the web config tool or directly over serial — not via the companion app.

The critical rule: nodes must share frequency, bandwidth, spreading factor, and coding rate to hear each other. If you’re starting with fresh firmware on both boards, the defaults will match. If one board was previously configured for a different region, check before you wonder why they can’t hear each other.

Step 3: Power on both nodes — start close

Put both nodes within 5 meters of each other. Not because that’s the real range (it isn’t), but because at close range you eliminate RF and placement variables entirely. You want to confirm the software is working before you test the physics.

Power on both Companion nodes and open the app on your phone, paired to one of them. Wait about 60 seconds.

Step 4: Confirm the link

In the MeshCore companion app, open the Contacts list. You should see the other node appear as a new contact within the first minute — MeshCore nodes broadcast periodic advertisement packets, and your companion picks them up. Tap the contact and check the SNR reading on the most recent advert.

Any positive SNR at 5 meters indoors is the right answer. At that distance you’re looking at +10 to +15 dB on a clear bench — the physics have no way to produce a weak signal that close. If you’re seeing a negative number or no contact at all, there’s a configuration issue: re-check frequency match, re-check that both boards are powered and running the right firmware.

Once you see the contact and a positive SNR, send a message. Watch it arrive. That’s your first working MeshCore link. The bench test is done.

Adding the Repeater

Move one Companion node to a different room or the other end of the space. Leave the other where it is. Power on your Repeater and place it roughly between them, elevated if possible (on a shelf, not on the floor).

Watch what happens in the app. Messages that previously needed direct range now route through the Repeater. In the contacts view, the hop count on packets from the far node will show 2 instead of 1 when the Repeater relays them.

This is the first working mesh topology: two endpoints and one relay. It’s exactly the same structure as a neighborhood-scale network — just smaller. Repeater placement is where the engineering of larger networks starts, but at this scale the logic is already visible.

Reading the numbers

The SNR reading that appears in the app on every received packet is the link quality signal. Higher is cleaner; lower is marginal. The threshold for a reliable link — the one worth building your network around — is roughly +5 dB or better in typical conditions. Below +3 dB, the link works most of the time; below 0 dB, count on occasional failures.

If you have Waev connected with an enrolled observer, those same SNR readings appear in Live Packets with timestamps and a persistent per-link history. That history is what lets you distinguish a transient interference event from a structurally weak link. Reading the Signal covers how to interpret what you’re seeing.