The RFD900u is a high performance 900MHz, ISM band radio modem covering the 902 – 928 MHz frequency band. It is designed to be the smallest, lightest and most sensitive diversity switched modem on the market.
- The smallest, lightest and most sensitive diversity switched modem on the market.
- Long range >10km depending on antennas and GCS setup
- 2 x u.FL RF connectors, diversity switched.
- 2 x user controllable I/O pins.
- 100 mW (+20dBm) transmit power.
- Integrated transmit low pass filter to reduce interference to other co-located radio links.
- Latest technology pHemt, high gain > 24dB, high linearity Low Noise Amplifier (LNA).
- Receive SAW filter for blocking out of band interference.
- Open source firmware SiK / tools, field upgradeable, easy to configure.
- Multipoint software capability with MP SiK (V2.x)
- 128kB flash, 8kB RAM – more space for customisation.
- Compatible with 3DR / Hope-RF radio modules.
- License free use in Australia, Canada, USA, NZ
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)
- Output Power: 100mW (+20dBm), controllable in 3dB steps .
- Air Data transfer rates: 4, 8, 16, 19, 24, 32, 48, 64, 96, 128, 192 and 250 kbit/sec ( 64k/128k default )
- UART data transfer rates: 2400, 4800, 9600, 19200, 38400, 57600, 115200 baud ( 57600 default )
- Receive Sensitivity: <-111dBm at 9.6kpbs, <-107 dBm at 64kbps, <-105dBm at 129kbps (air serial speed)
- Size: 19.0 mm (wide) x 30.4 mm (long) x 4.5 mm (thick) – Including RF Shield and maximum connector extremities
- Weight: 2.7g
- Mounting: 2 x M1.5 screws
- Power Supply: +5 V nominal, (+3.5 V min, +5.5 V max), ~190mA avg TX +20dBm, ~230mA peak TX +20dBm, ~77mA RX
- Temp. Range: -40 to +85 deg C
- RF : 2 x u.FL/IPX connectors
- Serial: Logic level RS232 (+3.3v nominal, +5v tolerant)
- Power: +5v, ~300mA max peak (at maximum transmit power)
- GPIO: 2 General purpose IO (Digital, ADC, PWM capable).
- Connector: DF13, 8 way connector (interface cables available from RFDesign)
Pin Signals and Layout
|Pin #||SiK Mapping||Name||Colour||Direction||Description||Max Voltage|
|7||–||CTS||White||Either||Clear to send||5V|
|5||–||Rx||White||Input||UART Data In||5V|
|4||–||TX||Blue||Output||UART Data Out||5V|
|3||–||RTS||White||Either||Request to send||5V|
In case there is need to force the modem into boot mode, short circuit Pins 1 and 2 or Pads labelled CTS and GND on the back of the modem (BIG Pads on edge of board)