HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old May 26, 2012, 01:02 PM
Registered User
Australia, QLD, Brisbane
Joined Nov 2011
118 Posts
New Product
RFD900 - Long range radio modem

Update - Multipoint software is now available!, please see our website or RFD900 product page for details.

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/index.php/rfd900

The RFD900 radio modems and accessories are now available at:
http://store.rfdesign.com.au/ (RFDesign - Australia)
http://store.jdrones.com/ (JDrones - Thailand)
https://www.event38.com/ProductDetails.asp?ProductCode=RFD900 (Event38 - USA)

Some of the key features of the RFD900 are as follows:
  • Multipoint link capable for multiple GCS stations and single air station with Mavlink
  • Easy to use, no adaptor or interface boards required
  • Long range >40km depending on antennas and GCS setup
  • 2 x RP-SMA RF connectors, diversity switched.
  • 1 Watt (+30dBm) transmit power, 1dB steps.
  • Air data rates programmable from 4k to 250kbit/s
  • Serial data rates from 2400 to 115200 baud.
  • Integrated Transmit low pass filter.
  • >20dB Low noise amplifier.
  • On board RX SAW filter.
  • Passive front end band pass filter.
  • Open source firmware (V1.x) / tools, field upgradeable, easy to configure.
  • Windows based configuration tools available.
  • Small (30 x 57 x 13 mm), light weight (14.5g including heatsink).
  • 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.
They are 100% compatible with 900MHz Hope-RF based radios (3DR) and similar.
These modems have been flying in various platforms and have demonstrated excellent performance in real applications.

A couple of Outback challenge UAV entries are testing these radios for long range communications

RFD900 modems are expected to be available in a few weeks time, before the end of June in production quantities.
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.

Will keep you posted with updates on performance, availability and in the meantime if you would like any more info, let us know!

Seppo Saario
rfdesign.com.au
Seppos is offline Find More Posts by Seppos
Last edited by Seppos; May 25, 2013 at 02:00 PM. Reason: Multipoint software available
Reply With Quote
Sign up now
to remove ads between posts
Old May 29, 2012, 04:02 AM
Registered User
Australia, QLD, Brisbane
Joined Nov 2011
118 Posts
A quick update on the RFD900 modems,

Production boards are due to arrive tomorrow (30th May), with a verification build happening towards the end of the week to make sure everything is still within spec.

One of the motivations on designing the RFD900 was the lack of features in existing modems tailored for UAV applications. I had not seen integrated support for antenna diversity which is very beneficial for mobile platforms like UAVs.
The diversity implementation on the RFD900 chooses the best antenna on a packet by packet basis. Having one antenna vertically polarised and the second antenna horizontally polarised (or both at +/- 45 deg) will cover most airframe attitudes reducing the chance of link loss.

Another thing is the attention to filtering - since most RC/UAV platforms operate with a number of radios, being "nice" in terms of reducing noise on other bands (especially GPS, 2.4GHz) is key. The RFD900 has integrated transmit low pass filtering and a chebyshev front end band pass filter on both the transmit and receive path.

Will post more updates on the production boards as they are built !
Seppos is offline Find More Posts by Seppos
Reply With Quote
Old May 29, 2012, 10:39 AM
Registered User
Near Austin
Joined Dec 2001
5,406 Posts
Have a target price?
CenTexFlyer is offline Find More Posts by CenTexFlyer
Reply With Quote
Old May 30, 2012, 07:59 AM
Registered User
Australia, QLD, Brisbane
Joined Nov 2011
118 Posts
Target price for the radios is $90 AUD per modem, pending final manufacturing costs from the contract manufacturer. I am still "convincing" them to reduce their build costs

There will be US based and Australian based distributors where modems can be purchased to reduce freight costs and transit time.

Production PCBs have arrived today, running through initial board level testing of the front end filters, LNA and PA. This will confirm that the PCBs have the same characteristics as the ones used prototype builds.

Will post some link results from actual flights shortly to show what kinds of results can be expected.
Seppos is offline Find More Posts by Seppos
Reply With Quote
Old Jun 05, 2012, 06:28 AM
vau
Registered User
UK
Joined Jan 2007
252 Posts
This I like the look of - a contender to knock the 9xstream out of top spot maybe.

Do you have latency figures for trasmitting (from the time into the UART on the TX side to out of the UART on the RX side) at 9600? Also what is the receiver sensitivity like at 9.6k - I see -120db suggested for 'low data rates' but does this mean 2.4k?

One of the things i found with the maxstream is that you really have to tweak the settings (retransmit, sleep time, packetisation etc) to get a good telemetry rate down and still have enough space and gaps in downstream transmission to send data back up.

Size and weight look great too.
vau is offline Find More Posts by vau
Reply With Quote
Old Jun 08, 2012, 12:08 PM
Registered User
Joined Feb 2012
813 Posts
Interesting. I like the idea of replacing my GCS 3DR Radio with a system with built in diversity...
epyonxero is offline Find More Posts by epyonxero
Reply With Quote
Old Jun 28, 2012, 07:24 AM
Registered User
Australia, QLD, Brisbane
Joined Nov 2011
118 Posts
RFD900 Modems are available for purchase from the RFDesign online store : http://store.rfdesign.com.au

End of last week we ran through SMT production in Melbourne, Australia and this week we have run through testing and finishing of the radios.

So far they have flown with a few open source autopilots, with nice range..
A datasheet with more detailed specifications is in progress.
Seppos is offline Find More Posts by Seppos
Reply With Quote
Old Jul 04, 2012, 12:45 PM
Registered User
Australia, QLD, Brisbane
Joined Nov 2011
118 Posts
RFD900 25km+ range from hilltop to ground level

We did some preliminary tests with the radios at full power, 1 Watt to see what is possible.

This was of course done in the middle of the night in the freezing cold (Winter in Brisbane, Australia).

One radio was on Mt Cootha, just to the northwest of the city, and the other radio was out of a car window on a wooden stick, connected to a laptop. (at ground level). This is quite nasty for multipath and noise at ground level.
We achieved a bit over 25km with this configuration, at standard air data rate settings (64k).
The picture below shows the two locations where we had a stable link.

The range can be significantly improved with getting the antennas raised above ground level and reducing air data rate which will reduce noise in the receive channel due to narrower filters.

The antennas used were the standard 1/2 wave dipoles at each end of the link.
Next tests will be to an airborne platform, with the GCS antenna elevated a couple of meters.
Seppos is offline Find More Posts by Seppos
Reply With Quote
Old Jul 05, 2012, 08:42 AM
Registered User
Joined Feb 2012
813 Posts
Thats pretty impressive with just dipole antennas.
epyonxero is offline Find More Posts by epyonxero
Reply With Quote
Old Jul 26, 2012, 02:38 PM
Registered User
Australia, QLD, Brisbane
Joined Nov 2011
118 Posts
Frozen RFD900

We decided to be cruel and do some extreme testing to see how the RFD900 modems behave under extreme cold conditions.

The modem was shut down and allowed to cold soak at -60 degrees C. Then powered up to maximum power and had a look at data transfer and connectivity tests. All works just fine.

The modems are available from Australia from the RFDesign web-store, but we are also making arrangements for a wider distribution network. -- Announcements coming soon!
Seppos is offline Find More Posts by Seppos
Reply With Quote
Old Jul 26, 2012, 04:04 PM
Registered FPVer :)
markus123456's Avatar
Switzerland, LU, Buchrain
Joined Aug 2006
2,853 Posts
Quote:
Originally Posted by Seppos View Post
Hi All,

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

[snip]

Will keep you posted with updates on performance, availability and in the meantime if you would like any more info, let us know!

Seppo Saario
rfdesign.com.au
Any information on what the achiveable data transfer rates are? I haven't found this info on your website...

Markus
markus123456 is offline Find More Posts by markus123456
Reply With Quote
Old Jul 26, 2012, 06:37 PM
Registered User
Near Austin
Joined Dec 2001
5,406 Posts
Quote:
Originally Posted by Seppos View Post
The modem was shut down and allowed to cold soak at -60 degrees C.
Shoot! You didn't have to worry about heat buildup did you? How about the other way? We fly in 110F pretty regularly. Keep it all enclosed and toasty in its' own little box.

and +1 on what Markus said.....
CenTexFlyer is offline Find More Posts by CenTexFlyer
Reply With Quote
Old Aug 01, 2012, 06:45 PM
Registered User
San Marcos, CA
Joined Aug 2009
2,866 Posts
This is highly interesting... any info when available in the USA?
flyandi is offline Find More Posts by flyandi
Reply With Quote
Old Aug 05, 2012, 07:59 AM
Rana
Gurgaon - India
Joined Jul 2009
154 Posts
What is the maximum RF baud of the RFD900 ?
It is nowhere mentioned at the product page.

Why two antenna port ? Are both ports transmitting - receiving ? Or one port is only dedicated TX port and the other dedicated RX port.

Generically receivers only have been seen with diversity antenna.
What highest baud the RFD900 would support with APM, without any link loss ?
narpat007 is offline Find More Posts by narpat007
Reply With Quote
Old Aug 05, 2012, 01:28 PM
Registered User
Australia, QLD, Brisbane
Joined Nov 2011
118 Posts
Thanks for the heads up! - yes, thats a pretty key bit of information - I have updated the product pages and website.

The air data rates supported are from 4k up to 250kbit/sec, these are settable via AT commands. The serial datarates are from2400 to 115200 baud. At the moment, the list of rates and commands are listed on the 3DR wiki from the RFD900 page. I will bring this information into the RFD900 pages for easy reference.

Two antenna ports are used for diversity. The Si1000 has built in diversity support such that it will select the best antenna for every packet. Both antennas get used for transmit and receive, depending on which has the best signal.
If you have a specific requirement for one antenna to transmit, the other to receive, it is possible to modify the open source firmware to do this.

Generally I have used APM 1 and 2, with the default settings, 57600 baud, 64k air data rates. If higher rates are needed, 115200baud, 250k air rates are available. It is also possible to turn off ECC and opportunistic resend to increase throughput. Typical throughput rates for mavlink data are in the order of 80% or so due to overhead from the TDMA framing overhead.

Due to popular demand I will undertake some mean HIGH TEMP tests on the modems. One modem will get a good roasting while at full power, maximum data transmission. . Any guesses on where it will get to before it kicks the bucket ?

Quote:
Originally Posted by narpat007 View Post
What is the maximum RF baud of the RFD900 ?
It is nowhere mentioned at the product page.

Why two antenna port ? Are both ports transmitting - receiving ? Or one port is only dedicated TX port and the other dedicated RX port.

Generically receivers only have been seen with diversity antenna.
What highest baud the RFD900 would support with APM, without any link loss ?
Seppos is offline Find More Posts by Seppos
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Range of 2.4GHz RF Modem? GuerillaFilm FPV Talk 1 Apr 18, 2013 07:06 PM
Discussion 12ch Radio relay for wireless long range UHF ground station i3dm FPV Talk 0 Mar 22, 2012 04:20 AM
Sold Short Range - Long Range ! 2x Lawmate receivers, 1x 1000mw VTX & 1x 50mw VRX crashtested FPV Equipment (FS/W) 7 Mar 11, 2012 06:32 PM
Discussion Radio Frequency for Long Range? AeroWRX FPV Talk 3 Feb 13, 2012 11:36 PM