Everything you wanted to know about the mesh

A single LoRa hop is line-of-sight dependent. In built-up areas with obstructions you might get a mile or two between devices; with real line of sight and a good antenna up high, a single hop can reach many miles, and well-elevated links can stretch well beyond that. The bigger story is the mesh itself: messages relay through repeaters, so the network's total reach is far greater than any one radio. MeshCore lets a message travel up to 64 hops node to node, so it can cross a whole region as long as there's a path — and coverage grows with every node the community adds.

They run on the same kind of cheap LoRa hardware but they are different, incompatible protocols, and a MeshCore node cannot talk to a Meshtastic node. The biggest practical difference is routing. Meshtastic relies on managed flood routing, where messages get rebroadcast widely. MeshCore uses hybrid routing: a message floods once to discover a path to its destination, then future messages follow that learned route directly. That means less airtime congestion and better behavior as the network gets dense. MeshCore also separates devices into clear roles — companion, repeater, and room server.

The mesh self-heals. There is no central server to fail. If a repeater that was carrying your messages goes offline, the learned path stops working, so MeshCore re-discovers a new route through whatever other nodes are available. As long as some path exists between you and your destination, the network will find it. This decentralization is a core reason mesh radio is so resilient during disasters: knock out one node and traffic simply routes around it.

Roughly, but not instant. Direct messages between nodes that are in range of each other arrive within seconds. Each additional hop adds a little delay as the packet is relayed along the route, and busy airwaves or longer paths add more. It feels like text messaging with a short lag, not a live phone call. For people who are offline or out of range, a room server acts as a store-and-forward post office, holding messages and delivering the previously unseen ones (up to 32) when that person reconnects.

A companion is your personal device, paired to your phone, that you send and receive messages with; it does not relay other people's traffic, which saves battery and keeps the airwaves clean. A repeater is pure infrastructure whose only job is to forward packets toward their destination using smart routing; mount it high and power it from solar or continuous USB to extend the whole mesh's reach. A room server is a store-and-forward bulletin board that holds messages for people who are offline and delivers them later, and it can also act as a repeater. Most members only ever need a companion.

LoRa range depends heavily on a clear line of sight, so height dramatically increases how far a signal travels. A repeater on a rooftop, hill, or tower can cover far more ground than one at street level. If you have a high spot, hosting a repeater is one of the most valuable things you can contribute.

It works in all of those, but performance varies a lot. LoRa penetrates buildings reasonably well at close range, so indoor-to-indoor over a short distance often works. Dense cities add obstructions that shorten each hop, which is exactly why repeaters mounted high (rooftops, towers) matter so much downtown. Mountains are a mixed bag: ridgelines and peaks make superb repeater sites with enormous line-of-sight range, but valleys and canyons can be shadowed. The fix in every environment is the same: get antennas up high and add repeaters where the terrain blocks line of sight.

A Heltec LoRa 32 V3 (around $20–30) plus a 915 MHz antenna is the most common starter. Pair it to your phone over Bluetooth, learn how the mesh behaves, and add a longer-battery or standalone device later. Always confirm the board is the US/915 MHz version.

Yes, for the United States. MeshCore runs on the 915 MHz LoRa band (902–928 MHz) here. The same boards are sold in 868 MHz (EU) and 433 MHz versions that will not interoperate with a US mesh, so check the band on the listing before you buy.

Yes. A room server can also take on the repeater role, forwarding traffic while it stores and delivers messages for offline users. You set the role by the firmware you flash.

Yes. MeshCore and Meshtastic run on the same popular LoRa boards, and you can switch between them by reflashing without damaging the device. You choose the network by flashing the corresponding firmware. The two networks do not interoperate, so a board running MeshCore cannot message one running Meshtastic.

The node usually just won't boot or behave correctly — for example loading a build for a different board onto a Heltec V3. Nothing is damaged. Reflash with the build that matches your exact board and role and you're back in business. Using the MeshCore web flasher's device selector avoids the problem.

A 5–10 W panel with a 3000–3500 mAh 18650 or a 2000–5000 mAh LiPo covers most single-radio repeaters. In northern winters, size the battery for 2–3 days with little sun. When unsure, over-spec both rather than risk a dead node.

It depends heavily on the device, firmware, and how it's used. A companion node spends most of its time listening and only briefly transmitting, so it sips power. In practice a typical companion board runs for a day or more on its internal battery, and much longer with a larger pack or a low-power firmware build. Repeaters that run continuously are usually powered from solar or a steady USB source rather than a small battery.

Because it protects your hardware. Powering on or transmitting a LoRa radio with no antenna attached can permanently destroy the radio chip, since the transmit energy has nowhere to go. Always connect the antenna before you power the device on or plug in USB, every single time, on every device. It's the one rule we will never stop repeating.