These steps turn a supported LoRa board into an RNode. They were tested on a Heltec WiFi LoRa 32 V4 on Linux, in Chrome. Flashing replaces the firmware that is on the board, such as MeshCore. Save anything you want to keep first.

Read Before you power on a radio first. Attach the antenna before you plug the board in.

Allow access to USB devices (Linux)

Your user needs permission to open USB serial devices. Do this once, with the group for your system:

SystemCommand
Archsudo usermod -aG uucp $USER
Debian, Ubuntu, Fedorasudo usermod -aG dialout $USER

Then restart the computer. Logging out may not be enough. Without this step, flashing stops with Failed to open serial port.

Get the firmware

Download the file for your board from the RNode firmware releases. For the Heltec V4 it is rnode_firmware_heltec32v4pa.zip. Do not unpack it.

Flash

  1. Plug the board in with a USB cable that carries data. Some cables only charge.
  2. Open the flasher in Chrome, Edge or Chromium.
  3. Choose your board.
  4. Open the 2 Firmware tab, select the .zip file and click to flash it. Pick the port when the browser asks.
  5. Wait until it says the firmware has been flashed. Do not unplug the board while it runs.

If it cannot connect to the board

The error is often Invalid custom reset sequence. Put the board into download mode by hand, then flash again:

  1. Find the two small buttons. On Heltec boards they are next to the USB port.
  2. Press and hold PRG (it may say USER or BOOT).
  3. While you hold it, press and release RST.
  4. Wait a second, then let go of PRG.

The board stays quiet in this mode. Press RST when flashing is done.

Set up the board

  1. Open the 3 Provision tab, choose your board and model, and click Provision. For the Heltec V4 the model is 868 MHz / 915 MHz / 923 MHz with PA.
  2. Open the 4 Hash tab and click Set Firmware Hash.
  3. Press RST.

Leave TNC mode disabled. Reticulum apps need it off.

Check that it works

Close the flasher page so it lets go of the board, then type this in a terminal:

rnodeconf /dev/ttyACM0 --info

You should see your board’s name under Product, and Firmware version. EEPROM checksum correct should appear near the top.

The signature warning

rnodeconf warns that the device is not verifiable and shows Device signature : Unverified. That is expected on a board you flashed yourself with this page. The warning does mean you should only flash firmware from the official sources it lists, and only trust a board if you flashed it yourself.