Features: Long range 40km depending on antennas and setup x 80km demonstrated by Edge Research labs on a balloon , 57km in , on Dipoles. 2 x RP-SMA RF connectors, diversity switched. 1 Watt (+30dBm) transmit power. Transmit low pass filter. 20dB Low noise amplifier, high IP3. SAW filter. All I/O ESD and filtered. Re implemented and Multipoint firmware, field upgradeable, easy to configure. Compatible with 3DR / -RF radio modules. Interfaces: RF : 2 x RP-SMA connectors. Serial: level TTL (+3.3v) Power: +5v, ~800mA max (at maximum transmit power) GPIO: 6 IO (Digital, , PWM capable). Software / Support: The software solution is an development called "". It has been re implemented to suit the new processor architecture available on the 32bit ARM processor core. A 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. rate (air/uart), frequency band, power levels. Integrated support for configuring the RFD900 radios is supported by Planner. The default are at 57600 , 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. configurable serial data rates and air datarates. Error correction routines, Mavlink protocol framing ( selectable) Mavlink radio status reporting (Local RSSI, Remote RSSI, Local Noise, Remote Noise) Automatic antenna diversity switching on a packet basis in . Automatic duty throttling based on radio temperature to avoid overheating. Important note: keep a distanceof more than when the two data transmission modules are powered on, otherwise it may cause abnormal frequency matching of data transmission and seriously burn the high-frequency circuit. main features RDF900A is a wireless data transmission module with small volume and performance. The main features are: 1. Regardless of transceiver design, each module is integrated with USB serial port chip, and USB and UART interfaces are automatically switched. USB takes precedence 2. Operating frequency range: 902-928 MHz, band 3. The transmitting circuit is designed with a low-noise amplifier 20DB, and a low-pass filter unit is added 4. The transmission power is adjustable, Maximum 1W transmit power 5. High sensitivity LNA and SAW circuits in front of receiving circuit 6. The outdoor communication distance can reach 40 km or more in a straight line (depending on antenna performance and communication rate requirements) 7. The air data rate can reach up to 250Kbps 8. Dual antenna interface, supporting antenna diversity and differentiated antenna configuration 9. Support AT configuration of local radio station and RT configuration of remote radio station 10. It has module temperature monitoring function and automatically adjusts the duty according to the temperature to avoid overheating 11. Working temperature - 40 to + 85 12. The size is 33mm x 53mm x 9.5mm 13. Weight: 23g Material: metal+plastic Color: as shown Package Contents: 1 x RFD900A 915Mhz 3DR Radio Telemetry Modem Module Kit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.