What is it?
RNode is an integrated, long-range data-radio that uses raw LoRa modulation in a variety of frequency bands. It connects to a host via USB or serial, or can be directly programmed for independent operation.
Or in short: A swiss army-knife of a LoRa-based communication device.
RNode can functions as a:
- LoRa interface for your computer (or any device with a USB or serial port)
- Packet sniffer for LoRa networks
- LoRa development board
- A LoRa-based KISS-compatible TNC
- Network adapter for RNS
- A flexible platform for experiementing with LoRa technology
- LoRaWAN support is coming in a future firmware update
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.
For adding RNode to your Arduino environment, please see this post.
For configuring an RNode, please have a look at the RNode Config Utility.
RNodes are now shipping, get yours from my shop
- 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
- 15 general 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
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.
- 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).
Resources and Downloads
- User manual
- Configuration utility
- 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 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.