RFDesign - RFD 868x Long Range Modem
The RFD 868x Modem by RFDesign is a ultra long-range RF modem with 1 Watt transmission power. This enables ranges of up to 40km (Peaks: 80km demonstrated by Edge Research labs on a balloon !, 57km in India, on Dipoles). The software "SiK" is an Open Source development. A Boot Loader and interface are provided for adjustments of model firmware via a serial port.
- Long range >40km depending on antennas and GCS setup *80km demonstrated by Edge Research labs on a balloon !, 57km in India, on Dipoles.
- 2 x RP-SMA RF connectors, diversity switched.
- 1 Watt (+30dBm) transmission power.
- Transmit low pass filter.
- > 20dB Low noise amplifier, high IP3.
- RX SAW filter.
- All I/O ESD protected and filtered.
- Re implemented SiK and Multipoint SiK firmware, field upgradeable, easy to configure.
- Small, light weight.
- Note: Not compatible with older modems
- RF : 2 x RP-SMA connectors
- Serial: Logic level TTL (+3.3v)
- Power: +5v, ~800mA max peak (at maximum transmission power)
- GPIO: 6 General purpose IO (Digital, ADC, PWM capable).
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
- EN: 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.
- The RFD868 is designed to be compliant with the following standards:
- FCC Part 15.247 (Frequency hopping and digitally modulated intentional radiators)
- AS/NZS 4268:2012 (Radio equipment and systems – short range devices)
- 1x RFD 868x Modem
- 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, 500 kbit/sec ( User selectable, 64k default )
- UART data transfer rates: 9600, 19200, 38400, 57600, 115200, 400k, 921k 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°