I would like to introduce you to a new radio modem that we developed for very long range datalinks!
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:
I have been fighting with these units for two days. We originally had two 900x hooked up to the platform but in order to shave the most possible weight off of them, I decided to get a 900u. Initially I could not get flash any firmware because the proper cable was not available (yes I do know I could have made my own)! After a day of trying to get the 900u to flash 2.5 multipoint firmware I was finally successful, did nothing different just kept plugging it in and trying again again and again, it finally flashed today. Our base station is running sik multipoint 2.53, now the two 900x we previously had working like a charm are not working at all MP fails to connect but does connect except it only loads 7-15 parameters and that is all. The only thing I could see that may be causing this is we have updated to 3.8.0beta 4 on our quadranger, it was perviously running 3.7.1 but we were unable to inject gps corrections in that version so we have upgraded. Im about at my wits end trying to trouble shoot these radios. I have attached a couple of photos of the error messages we have been getting in hopes someone can point me in the right direction. I also was wondering if someone has a copy of the FTDI drivers that are needed for using these as I think that may be an issue that is causing these to not work properly, I remember reading on RFD design that they wanted you to use a specific FTDI driver but cannot seem to relocate that documentation or the FTDI driver they had wanted you to use. Am I wrong in making the assumption that 900u and 900x should be able to talk to each other. Does it matter if base is running multipoint 2.53 and the air module is running a different version? Any and all help would be appreciated!!
Finally received my 8 way connector and now am having trouble flashing firmware RFD900u now shows red light when it is plugged in. Which tool are you suppose to use I have downloaded the datasheet for it but the screen shot on that shows a version of config tool that I cannot find anywhere is there a special tool to use or will the one that was used on the RFD900x work for 900u?
Many thanks. I would be interested in these when they are done if you wouldn't mind dropping me a note.
I did have success though by following your details, I got he zenner and capacitor and have tested our Jeti Rx9 with passthru on the RFD868x works a treat! Next step is to add other nodes.
Thanks again for your help very much appreciated.
Adapters we are making are for plug in modules directly into transmitter.
We are still working on enclosures for them.
We haven't made an adapter for the 5V to 3V input yet.
Justin Baxter said:
Thank you for the swift reply. You did mention that you guys might be selling adapters for this. Do you have these now?
If not then is there any particular amp rating required for the 3V Zener and the 1K resistor? Looking at geting from maplins to give it a go today..
Command description is here
As for your setup I assume you are using the Jeti Duplex R9 reciever PPM output and intend on connecting that to the rfd868x, and the R9 receiver is receiving signals from your jeti transmitter?
it seems like there are 2 ways to get PPM output from it.
Either should do.
See below for schematic of PPM wiring from Jeti to rfd868x ground side.
Air side will jut be wire from pin 15 to pixhawk ppm input. (+ ground wire of course).
Justin Baxter said:
Would it be possible to draw on your knowledge please.
We have just received our 868x units and we use Jeti Controllers. We would like to connect our Jeti Duplex R9 to the Ground RFD868x connected to MP and then have the Air RFD connected to our Pixhawk.
This is to allow us to be able to move out when our aircraft is within LOS and take over with our Controller.
I have setup the RFDs out of the box and they worked straight away for telemetry but I am just a little unsure of the necessary setup for the Input and Output on the other than the Pin 15 buy do not know how to do the voltage drop down on the ground side. Would you maybe have a diagram?
We have some more 900u to 8W cables in stock.
They come with the header pins to connect an FTDI cable for upgrade..
This is the recommended way to upgrade firmware on the 900u's
MATTHEW R CUNNINGHAM said:
I have a 4 RFD 900's [ the 1 watt version ] from about 3-4 years ago. Would there be any advantage to me updating the FW say for better range??
sure wish somebody made a df13 to usb wire...