Reflashing and Factory Reset

When a MeshCore repeater becomes unreachable, misconfigured, or boot-loops, reflashing is the recovery option. This page covers reflash procedures for all common device families.

When to reflash vs. when to reconfigure

Symptom	Try first	If that fails
Node working but wrong settings	Reconfigure via meshcli or serial CLI	Factory reset + reconfigure
Boot-looping or immediate crash	Power cycle; hold reset during boot	Reflash firmware
BLE not discoverable	Power cycle; V3: check BLE antenna	Reflash
Firmware corruption after interrupted flash	—	Reflash (required)
Unknown configuration state	Factory reset via serial: factory-reset	Reflash if serial inaccessible

Before reflashing: document your current config

If the device is still accessible, record its configuration before wiping:

meshcli info > node_config_backup.txt
# Records: name, ID, role, preset, TX power, position, advert settings

Reflash via MeshCore web flasher (recommended)

1. Connect device to PC via USB
2. Open meshcore.io/flasher in Chrome or Edge (WebSerial required)
3. Click “Connect” and select your device’s serial port
4. Select device type and firmware variant (Repeater)
5. Click Flash and wait (~2 minutes)
6. Device reboots automatically when complete

Entering bootloader/DFU mode (when auto-detect fails)

ESP32-based devices (Heltec V3, V4, T-Beam)

Hold the BOOT button, press and release RESET, then release BOOT. The device enters download mode and should appear as a serial port. Some devices require the BOOT button held while inserting the USB cable.

nRF52840-based devices (RAK4631, T-Echo, Nano G2 Ultra)

Double-tap the reset button quickly. The device enters DFU mode and appears as a USB drive named “BOOT” or similar. Copy the .uf2 firmware file to this drive to flash.

Alternatively, use the web flasher which handles DFU automatically for most nRF52840 devices.

Station G2

Power requirement: Station G2 requires 9–19V DC or a 15V USB-C PD source. It will NOT flash or boot reliably on a standard 5V USB cable. Use a USB-C PD charger that supports 15V or a proper DC power supply.

Post-reflash configuration

After flashing, the device has factory defaults. Reconfigure for repeater operation:

# Apply regional preset
meshcli set preset usa

# Set role
meshcli set role repeater

# Set name (use your documented name)
meshcli set name "REPEATER-NAME"

# Set position
meshcli set lat 47.6062 --lon -122.3321 --alt 150

# Set advertisement mode
meshcli set advert-hops flood
meshcli set advert-interval 720

# Set TX power (adjust for your antenna + EIRP compliance)
meshcli set txpower 27

# Verify
meshcli info

# Reboot
meshcli reboot

When the device is completely unresponsive

If USB serial doesn’t appear and the device shows no activity:

1. Try a different USB cable. Many micro-USB and USB-C cables are charge-only and have no data lines. Use a known-good data cable.
2. Try a different USB port. USB hubs can cause issues; try a direct port on the computer.
3. Install the correct driver: Heltec V4 requires the CH340 USB driver on Windows. RAK4631 and T-Echo use standard USB CDC (usually auto-installs).
4. Check for physical damage: Inspect the USB port for bent pins or corrosion. A damaged USB port prevents flashing.
5. Last resort: Some boards can be recovered via JTAG/SWD with a debug probe. Consult the manufacturer’s documentation.