RFD900, RFD900+ - New long range radio modem - Discussions

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

Michael,

The radio hops but it not spread spectrum. The number of channels used does not effect the timeslot duration(hop time) so fewer channels won't change data throughput. Best to leave it at 20 for Australia to be compliant. The rfd900+ uses the si1000 radio. The radio firmware is SiK if you want to delve into it's depths. I assume your using standard SiK code that it came with.

Kent.

Michael Shanaher said:

Hi all. I am using the RFD900+ modems for my high altitude UAV project and am about to conduct a range test. The goal is determine the maximum range afforded by the dipoles and see if I need to use a directional antenna to meet the requirements.

Part of this testing will involve changing some of settings and seeing how the radios perform in our environment, the aim being to find a balance between power consumption, telemetry rate and range.

I have a few questions:

Does anyone have any experience with experimenting with the number of FHSS bins? The obvious choice is the maximum number available in order to minimise the effects of noise. However, is there any advantage in selecting fewer bins? I could see there being an advantage of increased data rate if the dwell time is increased as the number of bins is decreased but I'm not sure if that's how it works. On that note, can anyone tell me what chip is being used so I can get a data sheet and look at how FHSS is implemented and how the number of frequency bins parameter affects the link.

I'll be sure to post back with the test set up and results.

FYI: we're aiming for 50 to 100 km.

Regards,
Mike

Replies

Seppo September 30, 2016 at 1:24am

Hi John,

I received your message a couple of hours ago. It does look like you have received a modem that has issues.

Our field failure rate is very low, but, unfortunately failures can occur with almost any product.

Regarding errors in documentation, feedback is always welcomed and incorporated.

I am arranging a replacement modem for you and apologise for the inconvenience caused.

With best regards,

Seppo
Developer

davidbuzz September 30, 2016 at 12:47am

Just for the record.... I'm not presenting un-educated opinion here. I know the manufacturer, they are in the same city as me. I have visited their offices many times.
John DeVere September 30, 2016 at 12:35am

davidbuzz said:
The manufacturer is most certainly not "abandon"-ing anything, quite the opposite, they have invested heavily in new design/s, features, code, etc, as will be seen soon enough.... and if you feel their documentation is lacking, then it's only got to be because they are so busy! They've recently moved to new/better offices too!

With regard to "one of them is bad" - If you've had it only a couple of weeks, it sounds like you need to see if it's a software or a hardware issue ( try re-flashing it, and then be sure to ensure all settings in both radios are 100% identical), and if it's a hardware issue, contact the manufacturer for a warranty claim.

I don't agree. And yes one of them is absolutely defective .. and yes I have contacted the manufacturer, who is the same as the original poster. And yes I am waiting for a reply.

And the documentation isn't just lacking, it's incorrect in so many places. And there are multiple versions with inconsistent information.. I've had to go through the code on github just to make sure I'm not hallucinating.
Developer

davidbuzz September 30, 2016 at 12:31am

The manufacturer is most certainly not "abandon"-ing anything, quite the opposite, they have invested heavily in new design/s, features, code, etc, as will be seen soon enough.... and if you feel their documentation is lacking, then it's only got to be because they are so busy! They've recently moved to new/better offices too!

With regard to "one of them is bad" - If you've had it only a couple of weeks, it sounds like you need to see if it's a software or a hardware issue ( try re-flashing it, and then be sure to ensure all settings in both radios are 100% identical), and if it's a hardware issue, contact the manufacturer for a warranty claim.
John DeVere September 30, 2016 at 12:01am

Mike Mac said:
Why are we getting zero support from the manufacturer?

I ordered a pair of rfd900's two weeks ago, I've had them a little while now, and one of them is bad.. I see features described two years ago, yet I don't see them. (Dynamic output power?) all the docs and firmware have the appearance of something that was abandoned long ago.

I bought these because I had just finished dealing with another product which was "released" two years ago, still has "beta" firmware and tools, and no support..

Now, I hope it's not as bad as it looks.. I'd like to hear what others customers have to say about this. Did anyone else purchase this perhaps based on an illusion?

I hope I'm just looking the wrong places... I want it to work!
Glen Leeon September 29, 2016 at 4:09am

I've just read on Ardupilot they recommend to run a separate 5v power line to the onboard radio. At the moment power is being fed from the Pixfalcon FC. Would this make any difference? It doesn't seem to matter if I connect to Mission Planner, however, no telemetry sent to QGroundControl.
Glen Leeon September 29, 2016 at 1:58am

I need some help with my connection.

Here is my setup. Hexicopter, Pixracer, D4R-II, 5.8Ghz - 600mw VTX

My first choice was to go with Mission Planner, so connected everything. Had telemetry from RFD but I could not get a good stable flight no matter what I tried.

So, I flashed PX4 and tried again. This time I get relatively stable flight (which I believe I can tune), but now no RFD data to QGroundControl. Also when connected this way, my computer suffers severe interference and sends the cursor all over the place on my screen opening windows disappearing just going mental. The green lights are solid (slight flickering) just like it is when I get good connection and data feedback from Mission Planner.

Anyone?

Thanks.
Soo Ting CH August 31, 2016 at 12:53am

HI,

I would like to know is this connection block could works? The 433mhz using normal apm telemetry.

https://storage.ning.com/topology/rest/1.0/file/get/3702291935?profile=original
Developer

Jani Hirvinen August 30, 2016 at 5:27am

Michael, if you have good antennas and a tracker. Reaching your target range is not a problem. There are users already who are reporting 100km range for RFD sets.

So have a good parabolic or yagi antenna on ground and have good finetuned antennas on your plane. Also remember to keep your ground antenna high enough :)
kent Martin August 30, 2016 at 4:57am

Michael,

The radio hops but it not spread spectrum. The number of channels used does not effect the timeslot duration(hop time) so fewer channels won't change data throughput. Best to leave it at 20 for Australia to be compliant. The rfd900+ uses the si1000 radio. The radio firmware is SiK if you want to delve into it's depths. I assume your using standard SiK code that it came with.

Kent.

Michael Shanaher said:

Hi all. I am using the RFD900+ modems for my high altitude UAV project and am about to conduct a range test. The goal is determine the maximum range afforded by the dipoles and see if I need to use a directional antenna to meet the requirements.

Part of this testing will involve changing some of settings and seeing how the radios perform in our environment, the aim being to find a balance between power consumption, telemetry rate and range.

I have a few questions:

Does anyone have any experience with experimenting with the number of FHSS bins? The obvious choice is the maximum number available in order to minimise the effects of noise. However, is there any advantage in selecting fewer bins? I could see there being an advantage of increased data rate if the dwell time is increased as the number of bins is decreased but I'm not sure if that's how it works. On that note, can anyone tell me what chip is being used so I can get a data sheet and look at how FHSS is implemented and how the number of frequency bins parameter affects the link.

I'll be sure to post back with the test set up and results.

FYI: we're aiming for 50 to 100 km.

Regards,
Mike

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