The RFD900x is a high-performance 900MHz, ISM band radio modem covering the 902 – 928 MHz frequency band. It is designed for long-range serial communications applications requiring best in class radio link performance.
New Features for the X series:
- New Processor, ARM 32 bit core.
- Air data rate: 500kbit/s.
- AES Hardware accelerated encryption. *Fully working*
- RC PPM Passthrough with telemetry at the same time.
- GPIO Pin Mirroring – see datasheet for more.
- Original SiK point to point firmware implemented.
- Asynchronous multipoint firmware, *Beta release*
- Long-range >40km depending on antennas and GCS setup
- 2 x RP-SMA RF connectors, diversity switched.
- 1 Watt (+30dBm) transmit power.
- Transmit low pass filter.
- > 20dB Low noise amplifier, high IP3.
- RX SAW filter.
- Passive front end band pass filter.
- Fully ESD protected + filtered – Every IO port is protected and filtered.
- Re-implemented SiK and Multipoint SiK firmware, field upgradeable, easy to configure.
- Small, lightweight.
- License-free use in Australia, Canada, USA, NZ.
- Note: Not air-compatible with older “+” series modems with current software.
The RFD900 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)
- Frequency Range: 902 – 928 MHz (USA) / 915 – 928 MHz (Australia) / 868 – 870 (European Band)
- Output Power: 1W (+30dBm), controllable in 1dB steps ( +/- 1dB @ <20dBm, +/- 0.5dB >=20dBm typical )
- Air Data transfer rates: 4, 64, 128, 250, 500 kbit/sec ( 64k/128k default )
- UART data transfer rates: 2400, 4800, 9600, 19200, 38400, 57600, 115200 baud , and higher. ( 57600/115200 default )
- 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 extremities
- 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.
- RF: 2 x RP-SMA antenna connectors – it is OK to have only one antenna connected
- Serial: Logic level RS232 (+3.3v nominal, +5v tolerant)
- Power: +5v, ~800mA max peak (at maximum transmit power)
- GPIO: 6 General purpose IO (Digital, ADC, PWM capable).
The following cable from FTDI is compatible with the RFD900 modem. Pin 1 of the FTDI cable connects to Pin 1 of the RFD900 header.
To power the modem from the +5V USB power, a jumper is needed between pins 4 and 6.
To power the modem from an external +5V supply, connect power to pins 2 and 4.
Pin Signals and Layout
|Pin #||SiK Mapping||Name 900a||Name 900u||Direction||Description||Max Voltage|
|3||–||CTS||CTS||Either||Clear to send||5V|
|5||–||Vusb||Vusb||–||Power Supply USB||5V|
|6||–||Vusb||Vusb||–||Power Supply USB||5V|
|7||–||RX||RX||Input||UART Data In||5V|
|9||–||TX||TX||Output||UART Data Out||5V|
|11||–||RTS||RTS||Either||Request to send||5V|
In case there is need to force the modem into boot mode, short circuit pads 1 and 2 (labeled BOOT) on the 9-way test pads.