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Flashing MeshCore Firmware

Flashing MeshCore Firmware

MeshCore firmware can be installed via the web flasher (easiest), the CLI tool, or OTA (over-the-air) for updates on already-running devices. All methods are covered below.

Method 1: Web Flasher (Recommended)

The web flasher at flasher.meshcore.io requires a Chromium-based browser (Chrome or Edge). Firefox does not support the WebSerial API and will not work.

  1. Open flasher.meshcore.io in Chrome or Edge.
  2. Connect your device via USB. Use a data-capable USB cable. Charge-only cables (common with power banks) will not expose the serial port. If the device does not appear, try a different cable first.
  3. Hold the BOOT button while plugging in (ESP32 devices) or double-tap the reset button (nRF52 devices) to enter bootloader mode.
  4. Select your device type from the dropdown.
  5. Select the firmware variant:
    • Companion — pairs with a phone app over BLE or USB
    • Repeater — autonomous relay node, no interaction needed
    • Room Server — store-and-forward message hub
  6. Click Flash. The process takes 1–2 minutes. Do not disconnect during flashing.
  7. After flashing completes, configure the device via the MeshCore app or CLI.

Method 2: CLI Flashing

The MeshCore CLI tool allows flashing and configuration from a terminal. Useful for bulk deployments or when the web flasher is unavailable.

pip install meshcore-cli

Connect via serial (USB):

meshcore-cli --serial COM3          # Windows
meshcore-cli --serial /dev/ttyUSB0  # Linux/macOS

Connect via BLE:

meshcore-cli --ble connect

Connect via TCP (remote node on same network):

meshcore-cli --tcp 192.168.1.100:4403

Method 3: OTA Update (ESP32 devices only)

For devices already running MeshCore firmware, OTA updates avoid needing a USB connection.

  1. In the MeshCore app, open the Command Line for your device.
  2. Type: start ota
  3. The device will create a Wi-Fi hotspot named MeshCore OTA.
  4. Connect your phone or computer to the MeshCore OTA Wi-Fi network.
  5. Open a browser and navigate to http://192.168.4.1/update
  6. Upload the new firmware file (.bin). Wait for the device to reboot.

Method 4: OTA Update (nRF52 devices)

nRF52-based devices use the Nordic DFU protocol for OTA updates.

  1. In the MeshCore app, type start ota in the Command Line.
  2. Use the nRF Device Firmware Update app (available for Android/iOS).
  3. Set packet count:
    • RAK4631: use 10
    • Heltec T114: use 8
  4. Select the firmware .zip DFU package and transfer.

Bootloader Entry by Device

DeviceMethod
Most ESP32 devices (V3, V4, T-Beam)Hold BOOT button while connecting USB
nRF52 (T-Echo, RAK WisBlock, Wio series)Double-tap reset button quickly
LilyGo T-Deck variantsDepress trackball while connecting USB
Heltec V4May need CH340 USB-serial drivers installed first

Post-Flash Configuration

After flashing, the device needs basic configuration before it will function on the network:

  • Set device name (used to identify you in the mesh)
  • Set region/frequency (ensure this matches your local regulations — 915 MHz for North America)
  • Set TX power (default is usually fine; reduce for indoor testing)
  • For Repeater variant: set the repeater name and ensure auto-start is enabled
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