Gets started with Meshcore

Mesh radio

After my last round of testing on the window sill, I realized we need to talk about how these radios actually talk to each other. Mesh radio is basically just small devices passing notes across town, bouncing the signal until it reaches the right person.

The two main firmwares we use right now are Meshtastic and Meshcore, and they handle that note passing in completely different ways. I have been playing with both, and here are my toughts regarding the differences.

Meshtastic

Meshtastic works like a loud crowded room where everyone repeats every single word they hear. It is super easy to set up for a spontaneous weekend hike or a outdoor event, since any new radio just joins the shouting match immediately.

The problem is that in a dense urban environment, all that shouting creates massive radio congestion. And in a low density city as where I live (and most Swedes) there will never be enough devices to get around all buildings.

Meshcore

Meshcore is entirely different, acting more like a structured postal system with dedicated mail carriers. It takes a bit more effort to set up the infrastructure, but the resulting network is incredibly stable and reliable.

The only real downside is that you have to flash separate firmwares for your companion devices and your repeater devices. You can not just grab any node from the scrap pile and expect it to do everything at once.

Repeater

So I dug into how the repeaters actually work, and it is pretty clever. A meshcore repeater occasionally sends out a flood advert, which basically tells all the local nodes exactly where it is and how to route traffic through it. Instead of everyone shouting, the repeater handles all the heavy lifting and pathfinding. This keeps the radio channels clear and drastically improves the reliability of the whole setup.

Companion

Then you have the companion nodes, which are the devices you actually carry in your pocket. They stay completely silent until you send a message, either communicating directly with another companion nearby, or routing it silently up to the nearest repeater. Because they are not constantly repeating background traffic, the battery life on a companion node is absolutely fantastic, and my handheld unit lasts forever now.

Try it out

If you want to try it out, you can just plug a board into your computer and use the flasher at https://meshcore.io directly in your browser. I mostly use the Heltec v3 or the Heltec v4 for my pocket companions, but a solid Heltec wireless stick works well enough for a repeater if you have one on the shelf. The whole network isn’t 100 percent finished yet, but I am already looking for the next improvement to get my coverage over those annoying hills.

I have also written a longer comparison between Meshcore and Meshtastic