RFDesign - RFD 868ux Modem

RFD868ux New Features:

• Fully compatible with RFD868x modems.
• Air data rate up to: 500kbit/s. 
• AES Hardware accelerated encryption.
• RC PPM Passthrough with telemetry at the same time.
• SiK point to point firmware.
• Note: Currently due to the bandwidth limitations of the 868 modems Asynchronous Mesh and Multipoint Firmware are not officially supported for the 868X modems and correct operation of this code cannot be guaranteed
• **It requires the "ux PIXHAWK2 to RFD900 Telemetry Cable" - 150/300mm to interface to your application.

Features:

• Long range >40km depending on antennas and GCS setup
• 2 x u.FL RF connectors, diversity switched.
• 1 Watt (+30dBm) transmit power.
• Transmit low pass filter.
• > 15dB Low noise amplifier, high IP3.
• RX SAW filter.
• All I/O ESD protected and filtered.
• Re implemented SiK firmware, field upgradable, easy to configure.
• Small, light weight.
• License free use in Europe, India

 Interfaces:

• RF : 2x u.FL RF connectors
• Serial: Logic level TTL (+3.3v)
• Power: +5v, ~800mA max peak (at maximum transmit power)
• GPIO: General purpose IO (Digital capable). 

Specifications:

• Frequency Range:  865-867 MHz
• Output Power: 1W (+30dBm), controllable in 1dB steps ( +/- 1dB @=20dBm typical )
• Air Data transfer rates: 12, 56, 64, 100, 125, 200, 224, 500 and 750 kbit/sec (User settable, 64kbit default)*
• UART data transfer rates: 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800, 1M baud (User settable, 57600 default)*

*note these values are correct as of version 3.16 SiK firmware

• Output Power: 1W (+30dBm) max
• Receive Sensitivity: >111 dBm at 12kbps, 105 at 64 kbps and 98 at 200kbps
• Size: 25 mm (wide) x 33 mm (long) x 10.4 mm (thick) - Including RF Shield, PCB and Heatsink.
• Weight: 10g
• Mounting: Stand alone cable connection
• 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

Software / GCS Support:

The software solution is an open source development called "SiK".  It has been re implemented to suit the new processor architecture available on the 32bit ARM processor core.  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.

Integrated support for configuring the RFD868 radios is supported by APM Planner.

The default settings are at 57600 baud, N, 8, 1, and 200k air data rate.

The RFD868ux manual is here: RFD900ux Manual

The RFD868ux SiK software manual is here : RFD900x Peer-to-peer Manual

Software features include:

• Frequency hopping spread spectrum (FHSS)

• Transparent serial link

• Point to Point

• Configuration by simple AT commands for local radio, RT commands for remote radio

• User configurable serial data rates and air data rates

• 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 real time

• 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.