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2026-04-05
reticulumrnodelorasidebandmeshchatoff-gridradiotutorial

Go Off-Grid: Connect Sideband or MeshChat to Your RNode

Connect Sideband or MeshChat to your RNode and send your first encrypted message over LoRa radio — completely off-grid, no internet required.

Go Off-Grid: Connect Sideband or MeshChat to Your RNode

This is Part 6 of a 12-part series on building private, resilient communication networks with Reticulum, LoRa, and associated tools.

You have a flashed RNode from Part 5. You have Sideband or MeshChat from Parts 3-4. Now we connect them and send a message over radio — no internet, no cell towers, no infrastructure.

What You'll Need

  • Two RNodes (you need at least two radios to communicate)
  • Two devices to run Sideband or MeshChat (phones, laptops, Raspberry Pis — any combination)
  • Both RNodes configured to the same frequency, bandwidth, spreading factor, and coding rate

This is the critical point: both radios must use identical LoRa parameters or they won't hear each other.

Option A: Sideband + RNode on Android

This is the most portable setup — your phone becomes a handheld encrypted radio communicator.

USB Connection (OTG)

  1. Connect the RNode to your Android phone with a USB OTG cable/adapter
  2. Open Sideband
  3. Go to Hardware → RNode
  4. Enable the RNode interface
  5. Select the serial port (it should auto-detect)
  6. Configure LoRa parameters:
  7. Frequency: e.g., 867200000 (867.2 MHz)
  8. Bandwidth: 125000
  9. TX Power: 7
  10. Spreading Factor: 8
  11. Coding Rate: 5
  12. Go to Connectivity → enable Connect via RNode

Sideband will connect to the RNode and you'll see the interface come up.

Bluetooth Connection

If your RNode supports Bluetooth (most ESP32-based boards do):

  1. First, enable Bluetooth on the RNode: bash rnodeconf -b /dev/ttyUSB0
  2. Put the RNode in pairing mode: bash rnodeconf -p /dev/ttyUSB0
  3. Pair the RNode with your phone via Android's Bluetooth settings
  4. In Sideband, go to Hardware → RNode
  5. Set the connection to Bluetooth
  6. Select your paired RNode
  7. Configure the same LoRa parameters as above
  8. Enable Connect via RNode in Connectivity

Now you can disconnect the USB cable. Your phone communicates with the RNode wirelessly over Bluetooth, and the RNode communicates with the world over LoRa.

Option B: MeshChat + RNode on a Computer

Configure Reticulum

Add the RNode interface to ~/.reticulum/config:

[[RNode LoRa Interface]]
  type = RNodeInterface
  enabled = yes
  port = /dev/ttyUSB0
  frequency = 867200000
  bandwidth = 125000
  txpower = 7
  spreadingfactor = 8
  codingrate = 5

Start MeshChat

meshchat

MeshChat will use the shared Reticulum instance, which now includes the RNode interface. Open the web UI and you're communicating over LoRa.

WiFi Connection to RNode

Some RNodes support WiFi connectivity. You can connect to them over TCP instead of serial:

[[RNode LoRa Interface]]
  type = RNodeInterface
  enabled = yes
  port = tcp://10.0.0.50
  frequency = 867200000
  bandwidth = 125000
  txpower = 7
  spreadingfactor = 8
  codingrate = 5

Replace 10.0.0.50 with your RNode's IP address. You can also use mDNS hostnames like tcp://rnodef3b9.local.

Testing: Two-Node Communication

Set up two stations:

Station A: - Device: Laptop running MeshChat - RNode: Connected via USB - LoRa config: 867.2 MHz, 125 kHz BW, SF8, CR5

Station B: - Device: Android phone running Sideband - RNode: Connected via Bluetooth - LoRa config: 867.2 MHz, 125 kHz BW, SF8, CR5 (must match!)

Steps:

  1. Start both stations
  2. On both, send an Announce to broadcast your identity over the radio
  3. Wait for each station to discover the other (you'll see the announce arrive)
  4. Send a message from Station A to Station B

The message travels: MeshChat → Reticulum → RNode A → LoRa radio → RNode B → Reticulum → Sideband. Fully encrypted, fully off-grid.

Range and Antenna Tips

With the stock antenna that comes with most development boards, expect:

  • Urban (buildings, streets): 500m - 2 km
  • Suburban: 2 - 5 km
  • Rural/line-of-sight: 5 - 15 km
  • Elevated position with good antenna: 15 - 30+ km

To improve range:

  • Upgrade the antenna. The stock antennas are terrible. A proper tuned whip antenna or a small Yagi makes a huge difference.
  • Get height. LoRa is line-of-sight at these frequencies. Mounting an antenna on a roof, pole, or high window dramatically improves range.
  • Increase spreading factor. SF10 or SF12 gives more range at the cost of speed. For text messaging, speed barely matters.
  • Reduce bandwidth. 62.5 kHz instead of 125 kHz doubles sensitivity but halves throughput.
  • Use the right frequency. Lower frequencies (433 MHz) penetrate obstacles better than higher ones (915 MHz) but need larger antennas.

What If You Only Have One RNode?

You can still use a single RNode as a radio interface on one end, and have the other end connect via the internet or local WiFi. This is useful for:

  • Testing your RNode setup before buying a second one
  • Connecting a remote off-grid station to an internet-connected gateway (covered in Part 9)
  • Providing radio coverage for an area while backhauling over TCP

Airtime and Duty Cycle

LoRa operates in shared ISM bands. Be a good neighbor:

  • Don't transmit continuously — LoRa is designed for intermittent, low-duty-cycle use
  • Configure airtime limits in your Reticulum config (see Part 5)
  • Text messages are tiny and well within any duty cycle limits
  • Avoid large file transfers over LoRa unless necessary

Troubleshooting

RNodes can't hear each other: - Verify identical LoRa parameters on both sides (frequency, bandwidth, SF, CR) - Check that both antennas are connected - Try reducing the distance to rule out range issues - Check rnstatus to confirm the RNode interface is Up

Sideband can't connect to RNode: - Verify the serial port is correct - On Android, make sure you granted USB permission when prompted - For Bluetooth, ensure the RNode is paired and Bluetooth is enabled on both devices - Try power-cycling the RNode

Messages sent but not received: - Both sides need to have announced for the other to know their address - Check rnpath -t to see if a path exists to the destination - LoRa is slow — give it time, especially at high spreading factors

What's Next

You're now communicating off-grid over encrypted radio. In the next guide, we'll build a proper handheld RNode — a portable, battery-powered communicator in a 3D-printed case.

Previous: [Part 5 — Flash an RNode] Next: [Part 7 — Build a Handheld RNode (Portable Off-Grid Communicator)]

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