RFD900x-US User Manual V2.0 www.rfdesign.com.au RFD900x-US Radio Modem User Manual 902-928MHz frequency band 1 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au General Cautions During operation there must be a separation distance of 20cm between all persons and the antenna. Ensure that all used RF connectors are secure and properly terminated. When used in the US - FCC Caution Caution: The user is cautioned that changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment. This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Note: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:
Reorient or relocate the receiving antenna. Increase the separation between the equipment and receiver. Connect the equipment into an outlet on a circuit different from that to which the receiver is connected. Consult the dealer or an experienced radio/TV technician for help. This equipment complies with FCCs RF radiation exposure limits set forth for an uncontrolled environment. The antenna(s) used for this transmitter must be installed and operated to provide a separation distance of at least 20 cm from all persons and must not be collocated or operating in conjunction with any other antenna or transmitter. Installers must ensure that 20cm separation distance will be maintained between the device
(excluding its handset) and users. When used in Canada - ISED Caution This device complies with RSS 210 of the Industry Canada Rules. Operation is subject to the following two conditions:
(1) this device may not cause interference, and (2) this device must accept any interference, including interference that may cause undesired operation of the device. Le prsent appareil est conforme aux CNR dIndustrie Canada applicables aux appareils radio exempts de licence. Lexploitation est autorise aux deux conditions suivantes :
(1) lappareil ne doit pas produire de brouillage, et (2) lutilisateur de lappareil doit accepter tout brouillage radiolectrique subi, mme si le brouillage est susceptible den compromettre le fonctionnement. This equipment complies with Canada radiation exposure limits set forth for uncontrolled environments. This equipment should be installed and operated with a minimum distance of 20cm may be adjusted according to actual calculation result between the radiator and your body. This transmitter must not be co-located or operating in conjunction with any other antenna or transmitter. Dclaration dIC sur lexposition aux radiations:
2 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au Cet quipement est conforme aux limites dexposition aux radiations dfinies par le Canada pour des environnements non contrls. Cet quipement doit tre install et utilis une distance minimum de 20 cm entre lantenne et votre corps. Cet metteur ne doit pas tre install au mme endroit ni utilis avec une autre antenne ou un autre metteur Acceptable Antennas - US This device has been designed to operate with the antenna(s) listed below and having a maximum gain of 3 dBi. Antennas not included in this list or having a gain greater than 3 dBi are strictly prohibited for use with this device. The required antenna impedance is 50 ohms. Acceptable antenna 3dBi RFD whip. Acceptable Antennas - Canada This radio transmitter 24610-900X2 has been approved by Innovation, Science and Economic Development Canada to operate with the antenna types listed below, with the maximum permissible gain indicated. Antenna types not included in this list that have a gain greater than the maximum gain indicated for any type listed are strictly prohibited for use with this device. Acceptable antenna 3dBi RFD whip. 3 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au Table of contents 1 2 Key Features .................................................................................................................................... 5 Specifications .................................................................................................................................. 6 3 OEM Labelling ................................................................................................................................. 7 4 5 6 7 Pin signals and layout ...................................................................................................................... 8 Physical dimensions ........................................................................................................................ 9 Software/GCS Support .................................................................................................................. 10 Diversity ........................................................................................................................................ 11 7.1 7.2 Spatial diversity ..................................................................................................................... 11 Polarisation diversity ............................................................................................................. 11 8 Network options ........................................................................................................................... 12 8.1 8.2 Simple pair (P2P) ................................................................................................................... 12 Asynchronous non-hopping mesh ........................................................................................ 12 8.3 Multipoint synchronised mesh ............................................................................................. 13 9 Frequently asked questions (FAQ) ................................................................................................ 14 9.1 9.2 How many antennas do I need to use? ................................................................................. 14 How do I connect the FTDI cable to the modem? ................................................................ 14 9.3 What do I need to upload the firmware or to change the modem configuration? .............. 14 9.4 I upgraded to asynchronous firmware and the modems don't connect anymore? ............. 14 How do I configure 2 base stations and one Airborne platform with 3 modems?
9.5
(Asynchronous) ................................................................................................................................. 14 10 11 Useful links ................................................................................................................................ 16 Revision History ......................................................................................................................... 16 4 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au 1 Key Features Features Out of the box RF communications. Air data rate speeds of up to 224kbps Diversity antenna support Weight of 14g Outdoor RF line-of-site range of 40km or more depending on antenna configuration Operational Operating voltage: 5V, I/O Voltage (3.3V) Temperature range: -40C to +85C Dimensions of 30mm x 57.7mm x 12.8mm Current consumption:
TX mode: ~1A peak at +30dBm, RX mode: 60mA (typical) Applications Telemetry data UAV control Remote weather station House automation Long range RC 5 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au 2 Specifications Performance Supported RF Data Rates Indoor Range Line-Of-Sight Range Transmit Power Receiver Sensitivity Low Noise Amplifier Features Serial Data Interface Configuration Method Frequency Band Interference Immunity Serial Interface Data Rate Antenna Connection GPIO Compliance Standards 12 to 224 kbps dependent on type and version of firmware 500m 1km 40km or more depending on antennas and settings 0 to 30dBm in 1dBm steps
>121dBm at low data rates
>20dB gain
+3.3V nominal, 3.3V tolerant AT Commands, APM Planner, RF Design Modem Tools 902MHz - 928MHz FHSS (Frequency Hopping Spread Spectrum) 2400 to 1000000 bps dependent on type and version of firmware 2 x RPSMA diversity switched ports 6 pins (Digital, PPM capable) FCC Part 15.247, AS/NZS 4268:2012 Networking and Security Addressing Options Channels Supported Network Topologies Network ID: 0 255 Up to 51 Frequency Hopping Channels Point-to-point and asynchronous mesh1 and multipoint synchronous mesh1 1 Only available in separate firmware versions available on the RFD website Power Requirements Supply Voltage Transmit Current Receive Current
+5V nominal (+5V min, +5.5V Max, +6V ABS Max),
~1A peak at max power
~60mA 6 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au 3 OEM Labelling For equipment containing the RFD-900x-US where the RFD-900x-US label is not visible the following applies. Equipment using the RFD 900x-US in the USA must display a label referring to the enclosed module. This label must contain the words Contains FCC ID: 2ADLE-900X2. Equipment using the RFD 900x-US in Canada must display a label referring to the enclosed module. This label must contain the words Contains IC ID: 24610-900X2. 7 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au 4 Pin signals and layout Pin #
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Name GND GND CTS Vcc Vusb Vusb RX GPIO5/P3.4 TX GPIO4/P3.3 RTS GPIO3/P1.3 GPIO0/P1.0 GPIO2/P1.2 GPIO1/P1.1 GND Direction
Either
Input Either Output Either Either Either Either Either Either
Description Ground Ground Clear to send Power supply Power supply from USB Power supply from USB UART Data In Digital I/O UART Data Out Digital I/O Request to send Digital I/O Digital I/O Digital I/O Digital I/O, PPM I/O Ground Max Voltage 0V 0V 3.3V 5V 5V 5V 3.3V 3.3V 3.3V 3.3V 3.3V 3.3V 3.3V 3.3V 3.3V 0V Figure 5-1: Physical pin layout of the RFD900x Radio Modem GPIO pins will configure for 40kOhm pull down or pull up based on setting as input or output. They can sink or source approximately 5 mA each. 8 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au 5 Physical dimensions 9 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au 6 Software/GCS Support The default firmware (see Useful Links) is a development of the open source project called SiK and was created by Mike Smith. It has been further developed and modified by Andrew Tridgell and RFDesign. The modems feature a boot loader to facilitate field upgrade of the modem firmware via the serial port. This is most easily performed by using the latest version RFD Modem tools (see Useful links) Parameters such as power levels, air data rates, serial speeds, GPIO pins etc can all be custom set by the user using the AT Command set, the RFD Modem Tools V2 or later and APM Planner. Default serial port settings are as follows:
57600 baud No parity 8 data bits 1 stop bit The RFD900x Radio Modem has many software features including:
Frequency Hopping Spread Spectrum Transparent Serial Link Configuration by AT commands for local radio, RT Commands for remote radio User configurable serial data rates and air data rates Error correction routines 128-bit AES hardware encryption with user settable key MAVLink protocol framing (user selectable) MAVLink radio status reporting (Local RSSI, Remote RSSI, Local Noise, Remote Noise) Automatic antenna diversity switching on a packet basis in real-time Automatic duty cycle throttling based on radio temperature to avoid overheating PPM (R/C signal) pass through (Control vehicle across radio). GIPO pin mirroring 10 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au 7 Diversity The RFD900x has two antenna ports and firmware which supports diversity operation of antennas. During the receive sequence the modem will check both antennas and select the antenna with the best receive signal. The antenna selected during receive is then also used for subsequent transmission. In the case of only one antenna connected, it will automatically select the port with the antenna connected. Testing by Silicon Labs has shown that link budgets can be improved up to the order of 8dB by employing a diversity scheme. 7.1 Spatial diversity Spatial diversity is the case where the antennas are separated by some distance from one another. It is recommended that two antennas connected to the RDF900 modem be separated by at least 25cm, more if possible. 7.2 Polarisation diversity Polarisation diversity is the case where the antennas are perpendicular to each other. i.e. one vertical, and one horizontal. This is effective in reducing multipath effects which affect one or the other polarisation. This scheme also helps to maintain the link between non-static objects such as aircraft performing acrobatics by increasing the likelihood that one antenna will maintain the same polarisation as an antenna on the other side of the link. Figure 8-1 depicts how two right-angle monopole antennas can be positioned to achieve polarisation diversity. Figure 8-1: Antenna configuration to achieve polarisation diversity 11 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au 8 Network options RFD900x support firmware for simple pair (peer to peer), asynchronous mesh network and multipoint network. Available for download from the website (see Useful Links). 8.1 Simple pair (P2P) The out-of-the-box firmware of the RFD900x radio modem is set to work in simple pair mode. If you purchased a bundle, you are only required to connect the antennas and supply to initiate the link. As soon as the pair synchronises, the on-board LED will become solid green. Nodes within range Node 1 Node 2 Figure 8-1 Peer to peer modem pair network 8.2 Asynchronous non-hopping mesh The asynchronous non-forwarding mesh firmware offers a straight forward communication option that allows the user to quickly transmit and receive data across a great distance between two or more nodes. Figure 9-2 depicts this communication topology. If all the nodes are within range and have compatible parameters, communication between them will succeed. 12 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au All nodes within range Node 0 Node 1 Node 2 Node 3 Node 4 Figure 8-2 Asynchronous mesh topology It is also possible to establish forwarding between nodes in the network. (See the asynchronous firmware datasheet for details) 8.3 Multipoint synchronised mesh The network requires that one of the devices assumes a base role to control the timeslot distribution of the surrounding radios. If one the nodes is out of the bases range, communication is still possible if the parameter SyncAny is properly set. Within base node range Node 0 Base Node 1 Node 2 Node 3 Figure 8-3 Multipoint mesh topology 13 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au 9 Frequently asked questions (FAQ) 9.1 How many antennas do I need to use?
One is the minimum. Two is recommended. 9.2 How do I connect the FTDI cable to the modem?
The black cable of the FTDI (pin 1) should connect to pin 1 on the modem as shown in Figure 10-1. Figure 10-1: An FTDI cable connected to the RFD900x modem 9.3 What do I need to upload the firmware or to change the modem configuration?
Download the latest firmware (see Useful Links). Download the RFD900x Modem Tools (see Useful Links). Connect the FTDI cable to the modem and to a computer. Use the RFD900x Modem Tools to upload the latest firmware or to change the modem configuration (see RFD900x Modem Tools User Manual). 9.4 I upgraded to asynchronous firmware and the modems don't connect anymore?
The default setting for a modem is to have a NODEID set to 1 and DESTID set to 2. As communication is addressed NODEID must be different for all units and DESTID will set the modems to connect to. 9.5 How do I configure 2 base stations and one Airborne platform with 3 modems? (Asynchronous) Set the Airborne platform as follows:
14 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au NODEID = 1 DESTID = 65535, (32768 from version 2.45F) MAVLINK = 1 Set the ground station as follows:
NODEID = 2 or 3 DESTID = 1 MAVLINK = 1 This will allow the airborne modem to handover to multiple ground stations as it flies from the coverage area of one ground station, to another. Both ground stations can be connected and can control the Airborne platform simultaneously. (APM Planner using MAVLink) 15 21/2/2022 RFD900x-US User Manual V2.0 www.rfdesign.com.au 10 Useful links RFD900x-US Firmware http://rfdesign.com.au/firmware/
RFD SiK firmware is default RFD Asynchronous firmware RFD Multipoint firmware RFD900x-US Flash Programmer http://rfdesign.com.au/downloads/
FTDI Cable documentation http://www.ftdichip.com/Support/Documents/DataSheets/Cables/DS_TTL-232R_CABLES.pdf 11 Revision History Version 1.0 1.1 2.0 2.1 2.2 Date 22/09/17 22/05/18 1/11/18 8/1/2019 21/2/2022 Changes Release document Updated to correct typos, mistakes and changes in new versions Updated for Compliance Add label details Update for Version 2 16 21/2/2022