RFD900+ Modem
RFD900+ Modem
The RFD900+ 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.
Key Features
- 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.
- RX SAW filter.
- Passive front end band pass filter.
- Open source firmware (V1.x) / tools, field upgradeable, easy to configure.
- Small, light weight.
- Compatible with 3DR / Hope-RF radio modules.
- License free use in Australia, Canada, USA, NZ.
Compliance
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)
Specifications
- Frequency Range: 902 – 928 MHz (USA) / 915 – 928 MHz (Australia)
- Output Power: 1W (+30dBm), controllable in 1dB steps ( +/- 1dB @ <20dBm, +/- 0.5dB >=20dBm typical )
- 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: >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
Interfaces
- 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.
http://www.ftdichip.com/Support/Documents/DataSheets/Cables/DS_TTL-232R_CABLES.pdf
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.
9 way test pad pinout
Physical pinout on the RFD900
Pin Signals and Layout
| Pin # | SiK Mapping | Name 900a | Name 900u | Direction | Description | Max Voltage |
|---|---|---|---|---|---|---|
| 1 | – | GND | GND | – | Ground | 0V |
| 2 | – | GND | GND | – | Ground | 0V |
| 3 | – | CTS | CTS | Either | Clear to send | 5V |
| 4 | – | VCC | VCC | – | Power Supply | 5V |
| 5 | – | Vusb | Vusb | – | Power Supply USB | 5V |
| 6 | – | Vusb | Vusb | – | Power Supply USB | 5V |
| 7 | – | RX | RX | Input | UART Data In | 5V |
| 8 | 0 | P2.3 | P3.4 | Either | Digital I/O | 5V |
| 9 | – | TX | TX | Output | UART Data Out | 5V |
| 10 | 1 | P2.2 | P3.3 | Either | Digital I/O | 5V |
| 11 | – | RTS | RTS | Either | Request to send | 5V |
| 12 | 2 | P2.1 | P1.2 | Either | Digital I/O | 5V |
| 13 | 5 | P0.1 | P1.0 | Either | Digital I/O | 5V |
| 14 | 3 | P2.0 | P1.3 | Either | Digital I/O | 5V |
| 15 | 4 | P2.6 | P1.1 | Either | Digital I/O | 5V |
| 16 | – | GND | Black | – | Ground | 0V |
In case there is need to force the modem into boot mode, short circuit pads 1 and 2 (labelled BOOT) on the 9-way test pads.