Experimental: a Cairn companion for the Heltec WiFi LoRa 32 V3. It builds but hasn't run on a V3 with this build (its last outing was the Cairn 107 preview). Please tell us what you see.
What experimental builds are. Use MeshCore-HeltecV3-Cairn130-2026-11-10-ble-full.bin unless you want the app over a USB cable. The V3 repeater build is in the normal Cairn 130 release, not here.
Cairn 130 for the Heltec WiFi LoRa 32 V3 -- companion test build (2026-11-10)
For the Heltec WiFi LoRa 32 V3 (ESP32-S3, SX1262, 0.96" 128x64 OLED, 8 MB flash). Not for the V4 or the
V2. Nothing in it can damage the board, and you can always flash MeshCore or Meshtastic back the same way.
What it is:
- The Heltec T096's one-button screen on the V3's OLED: Home dashboard (clock, date and time zone,
phone link, nodes heard, uptime), Messages, Nodes, Spectrum and the Menu with its Settings. The PRG
button does everything: a click steps the pages, a hold acts, a double-click goes back.
- Pair it from the Cairn app (CairnOS) or the MeshCore app, as any companion. The PIN is 123456.
The online update never offers this build: flash the next one by hand.
Files:
MeshCore-HeltecV3-Cairn130-2026-11-10-ble-full.bin the app over Bluetooth
MeshCore-HeltecV3-Cairn130-2026-11-10-usb-full.bin the app over the USB cable
the two -update.bin files for a V3 already on Cairn: at 0x10000,
keeps your identity, contacts and settings
FLASH IT (Chrome or Edge on a computer)
1. Open https://espressif.github.io/esptool-js/
2. Plug the V3 in with a USB-C data cable. Click Connect and pick its port.
No port, or it won't connect: hold PRG, press and let go of RST, let go of PRG, then Connect again.
3. Click Erase Flash and wait for it to finish (this clears the other firmware's settings).
4. Flash Address 0x0, the -full.bin above, then Program.
5. When it says done, press Disconnect, then press RST.
Back up your node's private key from the app first if the board has an identity you want to keep.
WHAT TO TELL US
- Does the screen show Home, the right way up and readable?
- Does the PRG button work: click, hold, double-click?
- Does it pair? Does it hear and send messages?
- With many contacts: does anything pause when an advert comes in, and are your contacts all there
after a restart? (This board has no PSRAM, so it saves the contact list the older way.)
- If it restarts or freezes: a serial log at 115200 baud from just before helps most.