A MeshCore companion starts with an empty contact list. You fill it two ways: by announcing yourself, and by hearing others announce themselves.
Send an advert
In the app, tap Advert (the megaphone). Two flavours:
- Zero-hop - heard only by nodes in direct radio range. Polite, cheap, good for "is anyone near me?"
- Flood - repeaters pass it along, so the whole local mesh learns you exist. Use this when you first set up and when you've moved somewhere new. Not every five minutes.
Anyone who hears it gets you as a contact. Anyone whose advert you hear - repeaters included - appears in Contacts with their role and how many hops away they were.
The Public channel
Every node ships with a Public channel. Messages there flood through repeaters to everyone within reach, encrypted with a shared default key - so "public" is accurate. Say hello there first; it's where you'll find out who's around. Regional or club channels use their own key and are added from a link or QR your state group shares.
Direct messages
Tap a contact and write. Direct messages are end-to-end encrypted to that contact's key and sent along a path - the specific repeaters your companion learned can reach them. You'll see the path on the message (each repeater's short id) and a delivery tick when the far end acknowledges. If there's no path and the contact isn't in direct range, the message simply won't go - MeshCore won't flood a DM.
Reading what you see
- SNR / RSSI on a contact: the last packet's signal quality. Above 0 dB SNR is comfortable.
- Hops: 0 means direct, 1+ means a repeater carried it.
- Last seen: when their last advert or message reached you. Old contacts don't go away on their own - prune occasionally.
Post a screenshot of your contact list in the state MeshCore group. People will tell you which repeaters you should be hearing and aren't, and that's how gaps get found.