RFD 868+ Modem

Features:

• Long range >40km depending on antennas and GCS setup2 x RP-SMA RF connectors, diversity switched.
• 1 Watt (+30dBm) transmit power.
• Transmit low pass filter.
• > 20dB Low noise amplifier, high IP3 (Updated on RFD868+)
• RX SAW filter.
• All I/O ESD protected and filtered (New on RFD868+)
• Open source firmware SiK (V1.x) / tools, field upgradeable, easy to configure.
• Multipoint software capability with MP SiK (V2.x)
• Small, light weight.
• Compatible with 3DR / Hope-RF radio modules.

 Interfaces:

• RF : 2 x RP-SMA connectors
• Serial: Logic level TTL (+3.3v nominal, +5v tolerant)
• Power: +5v, ~800mA max peak (at maximum transmit power)
• GPIO: 6 General purpose IO (Digital, ADC, PWM capable). 

Specifications:

• Frequency Range:  868 - 869 MHz
• Output Power: 1W (+30dBm), controllable in 1dB steps ( +/- 1dB @=20dBm typical )
• Air Data transfer rates: 4, 8, 16, 19, 24, 32, 48, 64, 96, 128, 192 and 250 kbit/sec ( User selectable, 64k default )
• UART data transfer rates: 2400, 4800, 9600, 19200, 38400, 57600, 115200 baud  ( User selectable, 57600 default )
• Output Power: 1W (+30dBm)
• Receive Sensitivity: >121 dBm at low data rates, high data rates (TBA)
• Size: 30 mm (wide) x 57 mm (long) x 12.8 mm (thick) - Including RF Shield, Heatsink and connector extremeties
• Weight: 14.5g
• Mounting: 3 x M2.5 screws, 3 x header pin solder points
• Power Supply: +5 V nominal, (+3.5 V min, +5.5 V max), ~800 mA peak at maximum power
• Temp. Range: -40 to +85 deg C, tested operational from -73 to +123 deg C.

Software / GCS Support:

Note: Firmware for the RFD868 is the same as RFD900, the board identity is defined in the bootloader.  The correct file to upgrade a RFD868 is RFDSik Vx.xx rfd900p.ihx

The software solution is an open source development called "SiK" originally by Mike Smith and improved upon by Andrew Tridgell and RFDesign. A boot loader and interface is available for further development and field upgrade of the modem firmware via the serial port.

Most parameters are configurable via AT commands, Eg. baud rate (air/uart), frequency band, power levels, etc., please see the 3DR wiki for commands below for now.

V2.x firmware has been updated to support multipoint networking on the RFD868/900.

V1.x (non multipoint) is suitable for point to point links - the sourcecode is located at:   https://github.com/RFDesign/SiK

The user manual / datasheet can be found here : RFD900 Datasheet

A software manual for SiK firmware is here : RFD868/900 Software manual

RFD868/900 configuration tool and firmware repository: RFDesign Files

3DR/RFD868,900 compatible configuration tool : http://vps.oborne.me/3drradioconfig.zip

Integrated support for configuring the RFD868/900 radios is supported by APM Planner, with other GCS solutions in development.

The default settings are at 57600 baud, N, 8, 1, and 64k air data rate.

Software features include:

• Frequency hopping spread spectrum (FHSS)
• Transparent serial link
• Point to Point, or Multipoint networking
• Configuration by simple AT commands for local radio, RT commands for remote radio
• User configurable serial data rates and air datarates
• Error correction routines, 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 realtime
• Automatic duty cycle throttling based on radio temperature to avoid overheating 

Compliance :

The modem is designed for system integrators who will integrate the modem into their own projects and product prototypes.  The user is responsible for compliance with local regulations for radio transmitters.