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RFD900, RFD900+ - New long range radio modem

Posted by Seppo on May 25, 2012 at 8:15am

Hi All,

I would like to introduce you to a new radio modem that we developed for very long range datalinks!

http://rfdesign.com.au/RFD900.php

Some of the key features of the RFD900 are as follows:

  • Multi point and point to point link capability.
  • 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 / tools, field upgradeable, easy to configure.
  • Small (30 x 57 x 13 mm), light weight (14.5g).
  • Compatible with 3DR / Hope-RF radio modules.
  • License free use in Australia, Canada, USA, NZ.

 

These modems are designed to support long range applications, while being easy to use and affordable.  

These modems have been flying in various platforms and have demonstrated excellent performance in real applications. 

RFD900 modems are now available at: http://store.rfdesign.com.au

Support within APM planner and the radio configurator from Michael Oborne is already available.

It works seamlessly with APM planner, all radio Mavlink parameters are available.

Update, December 2014:  The RFD900+ with improved specifications is available now at:

http://store.rfdesign.com.au/rfd-900p-modem/

Seppo Saario

rfdesign.com.au

 

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Replies

  • kent Martin February 15, 2017 at 1:25pm

    Reuben,

    I had a look at the taranis and there is a telemetry port connector in the battery compartment.

    However I'm not sure of the data format. If it is the same as the standard mav data sent from the flight controller then you may be able to run the tx line from the rfd900 into the rx pin on the taranis (and ground of course). This is 0-3.3V on the RFD900x. This pin is used by your ftdi usb serial converter of course , so you would need a way to piggy back both ports onto the one connector. Maybe we can make this easier with a module in future so any input will be useful for making decisions on what requirements are.

    Reuben said:

    Hi I see its possible to use the radios as TX and RX for control ..so we don't have to use std rc receivers .. The question is, can it possible to get the mavlink data onto the Taranis Radio screen? Normally we would use a converter connected to the the Frsky Rx data port for down streaming to the radio. so since there would now be no Frsky Rx ..how could this be achieved? Thanks 

  • Jeremy Stromsoe February 14, 2017 at 6:59pm

    SOLVED!!

    @Seppo

    All, this boiled down to a bad whip antenna attached to the ground side RFD900+.  I was flying one day with the tracker and had a buddy troubleshoot hardware by disconnecting individual components.  Once we unscrewed the whip, the Bi-Quad Antenna from VAS worked rock solid.  Highly recommend antennas from Video Aerial Systems.  

    One thing I want to add is the Flexible PCB Antenna from RFD on the air side, which I did get in from Australia (I live in California, DHL Shipped in 4 days!).  Question is about that (and all antennas on the RFD site) could you provide a polar -3dB plot for that antenna so I can see where the beamwidth drops off?  That way I can figure out a proper mounting orientation etc.  Here's an example. 

    I thought about mounting it on the bottom of my quad against a thin layer of carbon fiber, but without a beam plot I have no idea if that is optimum or not.  


    Jeremy Stromsoe said:

    All in the know about RFD900 radios with Mavlink based telem data.

    So believe it or not I'm having some range issues with my RFD900+ radios.  I keep reading and reading and hearing about how folks are getting 10km or 15km or more with the 30dBm setting and 64kbps bandwidth, but I'm getting ~1000ft!  No problems actually connecting, just really short range before degradation, details on setup below.  I'm putting ample power into both RFDs so I just can't figure out what the problem is.  Wondering if anyone has experienced something similar or maybe I just have defective radios?

    I got my antenna tracker up and working with a 900MHz biquad attached to the rfd900+ but my telemetry link is marginal at best even at 1000ft away.  My tracker actually stops pointing due to data loss at anything more than that.  Any thoughts?  I have quarter wave dipoles on the "tx" end and on the "rx" end I've got my tracker with one biquad and one larger whip.  I'm only running the radios at 20dBm power output (default) but I should still get much further than 1000ft!  I put tx and rx in quotes since the link is obviously bidirectional.  Here's a couple photos of my setup.  Any help would be greatly appreciated. 

    ?ui=2&ik=68f5b70eba&view=fimg&th=159809653763e3aa&attid=0.1&disp=emb&realattid=1598095a482c6d3a241&attbid=ANGjdJ9-vD9oVpnk-m0iRKTWVQNA2taE4_Vr4Qgg4X91UgtiRQdNxfqdZRQXaZKp7PFxhgALpe4NC9xLrlI7YvbJKJMeWmRyznruH__TqmvJ1MDVW7-H4r9j4m2XBO8&sz=s0-l75-ft&ats=1484076405034&rm=159809653763e3aa&zw&atsh=1

    ?ui=2&ik=68f5b70eba&view=fimg&th=159809653763e3aa&attid=0.3&disp=emb&realattid=1598095ea00a82726233&attbid=ANGjdJ9zmE0YStutUTJGSvY4X0pv2lT6FOXiNt5NQW_A3A1jL7aZzomv2M8bXcQENe1ua3gdqLMWupYBghjSdaBPU9if2ctuXPdS6tMuLNJaLrVOqUq6cIfvuod1F0k&sz=s0-l75-ft&ats=1484076405034&rm=159809653763e3aa&zw&atsh=1
    ?ui=2&ik=68f5b70eba&view=fimg&th=159809653763e3aa&attid=0.2&disp=emb&realattid=1598095d42a43e112222&attbid=ANGjdJ8vSn_G2IDqnl45RZmky0MiMB5Yq4ZOto8C1Wwcpd9XIc3jPfzO4FGDMAELgNWuT6Z8E5huZ9yY-v-ujMMlz-1AEH9ip33GYjABRE6f7Z3S3vOku4XVeiM9k4A&sz=s0-l75-ft&ats=1484076405034&rm=159809653763e3aa&zw&atsh=1
    helical beamwidth polar - Google Search
  • kent Martin February 7, 2017 at 10:11pm


    Reuben,

    Could you elaborate more? I'm assuming here the frsky has a data port as well? 

    How does it get back into the taranis? SBUS? or other port?

    External wiring or is it directly into the back where the module plugs in?

    The mav serial data comes out the normal serial port on the RFD900x (TTL rs232 serial data) 

    which normally goes through a FTDI converter back to your PC. 

    If you want this in the taranis we need to know what format and where to put it to see if it is feasible.

    A plug in tx module would be the ideal case , so if we can get a bit more info it might make into our product development.

    Thanks.

    Reuben said:

    Hi I see its possible to use the radios as TX and RX for control ..so we don't have to use std rc receivers .. The question is, can it possible to get the mavlink data onto the Taranis Radio screen? Normally we would use a converter connected to the the Frsky Rx data port for down streaming to the radio. so since there would now be no Frsky Rx ..how could this be achieved? Thanks 

  • kent Martin February 7, 2017 at 10:04pm

    Right,Got it. The Frsky XM+ doen't support PPM however I believe, so it wouldn't be able to be used with the PPM functionality of the RFD900x. SBUS is not currently supported.

    Not to say that it can't be on this hardware, but all things in time.


    Vadym Yunyk said:

    Kent

    receiver is connected to the RFD900x on the ground. 

    Taranis X9D --- Frsky XM+ ---- RFD900x


    kent Martin said:


    Vadym,

    This thread is about PPM which negates the need for a receiver as long as your control systems can use a PPM stream.

    I don't understand why you need to use a receiver with the RFD900x?


    Vadym Yunyk said:

    I can use the receiver FrSky XM+ with RFD900x?

  • Reuben February 6, 2017 at 11:19am

    Hi I see its possible to use the radios as TX and RX for control ..so we don't have to use std rc receivers .. The question is, can it possible to get the mavlink data onto the Taranis Radio screen? Normally we would use a converter connected to the the Frsky Rx data port for down streaming to the radio. so since there would now be no Frsky Rx ..how could this be achieved? Thanks 

  • Vadym Yunyk February 6, 2017 at 8:38am

    Kent

    receiver is connected to the RFD900x on the ground. 

    Taranis X9D --- Frsky XM+ ---- RFD900x


    kent Martin said:


    Vadym,

    This thread is about PPM which negates the need for a receiver as long as your control systems can use a PPM stream.

    I don't understand why you need to use a receiver with the RFD900x?


    Vadym Yunyk said:

    I can use the receiver FrSky XM+ with RFD900x?

  • Thomas Stanley-Jones February 6, 2017 at 6:21am

    Could someone tell me how I can set up a radio to listen only?  I'm using 2.6 firmware with RFD900+ and have them setup for multiple basestations.  But it would be great if the other basestations were only for watching and won't transmit back to the copter.  Keep from accidental control actions by the non-pilots.

  • kent Martin February 5, 2017 at 3:14pm


    Vadym,

    This thread is about PPM which negates the need for a receiver as long as your control systems can use a PPM stream.

    I don't understand why you need to use a receiver with the RFD900x?


    Vadym Yunyk said:

    I can use the receiver FrSky XM+ with RFD900x?

  • Vadym Yunyk February 4, 2017 at 4:30am

    I can use the receiver FrSky XM+ with RFD900x?

  • Michael Nunan January 31, 2017 at 7:04am

    Got it working (with a digital scope as target so far).

    I used pin 15 on both ends of the link (Pin 2.6 in my documentation).

    3702347113?profile=original

    I did not have to use the AT Commands mentioned in the post

    AT commands are:
    1. for PPM input (ground)(pin 15 of header GPIO1.1,GPI1_1R/CIN ) "ATI16 = 1 "
    2. for PPM output (pin 15 of header GPIO1.1,GPI1_1R/COUT ) "ATI17 = 1 "
    3. to record the PPM stream for link loss "AT&R"
    I just used Mission Planner to do the setup. I will be looking into the AT&R to see if we need to use it.
    3702347331?profile=original
    Thanks
    Michael Nunan
    https://storage.ning.com/topology/rest/1.0/file/get/3702347113?profile=original
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