An RNode is an integrated, long-range data-radio that uses raw LoRa modulation in a variety of frequency bands. You can think of it as a general-purpose LoRa-based network card for your computer or mobile device. It connects to a host via USB, UART serial, Bluetooth or WiFi. It can also be programmed for independent operation. In short: A swiss army-knife of a LoRa-based communication device.
You can turn different kinds of LoRa development boards into an RNode, build one yourself, or buy a ready-to-use version from my shop. Self-built versions, and RNodes repurposed from other LoRa dev boards will be functionally identical, but may come in many different shapes and sizes, and have different pin layouts. Most of the details on this page concern the original RNode design, but will also be applicable to any other type of RNode.
An RNode can functions as a:
- Network interface adapter for Reticulum
- LoRa development board
- LoRa-based KISS-compatible amateur radio TNC
- Packet sniffer for LoRa networks
- flexible platform for experiementing with LoRa technology
- LoRa interface for any device with a USB or serial port
- LoRA-based network interface for Ethernet and IP over LoRa
- General-purpose long-range data radio
RNode is controlled by a powerful ATmega1284p MCU, and is fully Arduino compatible. You can use the included firmware, or it can be programmed any way you like, either from the Arduino IDE, or using any of the available tools for AVR development. The included firmware can also be edited and compiled directly from the Arduino IDE.
- High-quality LoRa module with genuine Semtech SX1276 chip
- Powered by an ATmega1284p MCU clocked at 16 MHz
- 128 kilobytes of flash
- 16 kilobytes of RAM
- Large payloads with a packet MTU of 500 bytes
- Up to 17 dBm continuous TX output in 820-1020 MHz
- Up to 14 dBm continuous TX output in 410-525 MHz
- Sensitivity down to -139 dBm
- Data rates ranging from 20 bps to 21.88 kbps
- Mini-USB connector
- SMA antenna connector
- Fully programmable
- Arduino compatible
- Open source firmware and config util
- 17 multi-purpose IO ports available
- All ports can be used as digital inputs or outputs
- 5 ports can be used as analog inputs
- An extra UART serial port is available on two of the pins
- I2C port
- Two PWM outputs are available
- JTAG port available
- Operating range: -20°C to 60°C (non-condensing)
- 23.3 mA idle power consumption
RNode can operate in the following two frequency bands:
- 410 - 525 MHz
- 820 - 1020 MHz
Custom made or RNodes made from repurposed boards may be able to utilise other frquency bands depending on their transceiver setups.
RNode can operate in two modes, host-controlled (default) and TNC mode:
- When RNode is in host-controlled mode, it will stay in standby when powered on, until the host specifies frequency, bandwidth, transmit power and other required parameters. In host-controlled mode, promiscuous mode can be activated to sniff any LoRa frames on the specified channel configuration.
- When RNode is in TNC mode, it will configure itself on powerup and enable the radio immediately. This mode can be enabled by using the configuration utility (the utility will guide you through the settings if you don't specify them directly). This is useful for using RNode as an amateur radio TNC with any legacy packet radio applications.
Resources and Downloads
- User manual
- Download configuration utility
- Configuration utility documentation and source
- Firmware downloads and source code
- LoRa packet sniffer program for RNode
- Programming examples
- Schematics and design files
- Adding RNode to the Arduino IDE
Examples and Learning Resources
If you want some inspiration to get started with RNode, have a look at the following examples. Most of them contain step-by-step instructions on how to do them yourself.
- Using RNodes With Amateur Radio Software
- Super long distance SSH link
- RNode as wireless network card
- APRS over LoRa
- LoRa packet sniffing
Pinout and Overview
Using the included libraries, it's easy to use RNode in your software. Here's a Python example:
from RNode import RNodeInterface def gotPacket(data, rnode): print "Received a packet: "+data rnode = RNodeInterface( callback = gotPacket, name = "My RNode", port = "/dev/ttyUSB0", frequency = 868000000, bandwidth = 125000, txpower = 2, sf = 7, cr = 5, loglevel = RNodeInterface.LOG_DEBUG) rnode.send("Hello World!")
USB and Serial Protocol
You can communicate with RNode either via the on-board USB connector, or using the serial pins on the board (labeled RX0 and TX0). RNode uses a standard FTDI USB chip, so it works out of the box without additional drivers in most operating systems.
All communications to and from the board uses KISS framing with a custom command set. RNode also does not use HDLC ports in the command byte, and as such uses the full 8 bits of the command byte is available for the actual command. Please see table below for supported commands.
|Data frame||0x00||A data packet to or from the device|
|Frequency||0x01||Sets or queries the frequency|
|Bandwidth||0x02||Sets or queries the bandwidth|
|TX Power||0x03||Sets or queries the TX power|
|Spreading Factor||0x04||Sets or queries the spreading factor|
|Coding Rate||0x05||Sets or queries the coding rate|
|Radio State||0x06||Sets or queries radio state|
|Radio Lock||0x07||Sets or queries the radio lock|
|Device Detect||0x08||Probe command for device detection|
|Promiscuous||0x0E||Sets or queries promiscuous mode|
|Ready||0x0F||Flow control command indicating ready for TX|
|RX Stats||0x21||Queries received bytes|
|TX Stats||0x22||Queries transmitted bytes|
|Last RSSI||0x23||Indicates RSSI of last packet received|
|Random||0x40||Queries for a random number|
|Firmware Version||0x50||Queries for installed firmware version|
|ROM Read||0x51||Read EEPROM byte|
|ROM Write||0x52||Write EEPROM byte|
|TNC Mode||0x53||Enables TNC mode|
|Normal Mode||0x54||Enables host-controlled mode|
|ROM Erase||0x59||Completely erases EEPROM|
|Error||0x90||Indicates an error|
A few notes on the EEPROM
As a completely open device, RNode does not block you from modifying the EEPROM contents, which specifies things like radio parameters, serial number, manufacture date and similar. But please be aware that doing so might render the device inoperable or burn out the radio. Before making any modifications, please make sure to create a backup of the EEPROM. RNode includes a cryptographic signature of the EEPROM contents, which validates all the information stored within it. You will not be able to re-create a valid signature if you erase it! Without this signature, the board will still function, but warranty will be void. If you upload your own programs or alternative firmwares to RNode, you should make sure that they don't write to the last 200 bytes of EEPROM. You can back up your EEPROM with the config utility.
How do I get it?
You can buy one from my shop, or make it yourself. Using the circuit design files, it is possible to build a fully functional RNode on a breadboard. See the following articles for more info on how to easily make your own RNodes from common boards: