Most “my node can’t see the others” problems come down to one of four things: the region, preset or channel don’t match; the antenna; the firmware; or the radio band of the board. Work through them in that order.
This happened to us: a Heltec V3 sat next to two working XIAO boards and never heard them, and they never heard it.
1. Compare the radio settings. All nodes need the same region, preset, channel name and key, and so the same frequency. Run tools/radio_check.py on each board; it lists them side by side and stars any difference. In our case everything matched: NP_865, LONG_FAST, the default key, and 867.875 MHz on both.
2. Check the radio chip starts. Open the serial monitor in the web flasher, press reset and look for SX1262 init success and Frequency set to 867.875. Ours started fine.
3. Swap antennas. Put a known-good antenna from a working board on the deaf one. It made no difference for us.
4. Match the firmware. The Heltec was on 2.7.26 and the XIAOs on 2.5.2. After reflashing the Heltec to match, it immediately heard both XIAOs at −21 to −56 dBm, and they heard it. Keep every board on the same firmware version, and read the release notes before upgrading only one node.
5. Check the band. Low-band (433/470 MHz) and high-band (868/915 MHz) versions of many boards look the same; Nepal needs high band. See Hardware.
Our first reflash accidentally installed a very old 2.0.x build. It talked to the others on the default channel, but meshtastic --device-metadata showed hw_model: UNSET and hasPKC: False, which means no encrypted direct messages. Reflash with the exact board name (for example Heltec V3) and a current version, and check:
meshtastic --device-metadata # expect your firmware version, the right hw_model, hasPKC: True
Only one program can use a board’s USB serial port at a time. Close the browser web client, the web-flasher serial monitor, the control panel, paxwatch.py and any other meshtastic command, then try again.
After a full erase the region is unset and the radio stays silent. Run meshtastic --set lora.region NP_865 and wait for the reboot.
Boards without GPS or an internet connection don’t know the time, so the “last heard” stored on the board can be wrong. The control panel times each packet with the computer’s clock instead.
Go through the map checklist. The usual misses are OK to MQTT being off, precise location left on, a 5 GHz-only WiFi network, or a custom channel key.
WiFi and Bluetooth must be off on the Paxcounter node, and it must be an ESP32 board. Reports arrive only once per interval (for example every 60 s). See Paxcounter.
meshtastic --info output publiclyThat output contains the node’s private key and possibly your WiFi password. Regenerate the keys (the security settings in the web client) and change the WiFi password.
Still stuck? Try the Meshtastic FAQ or open an issue.