hi all,
i am using a 433 mhz, 3dr radio telemetry. i have thought 433 mhz to be of good frequency for a longe range radio telemetry. however when i am using it in the field, i find the range of the telemetry module to be no more than 30 meters radially.
i would like to know how to increase the range on the module. i am using the supplied omni antennas.
thanks in advance
Replies
Hi all,
I have narrowed down this problem that people seem to be having with their telemetry radios giving very poor range. It appears that the Android apps Tower and Droid Planner both return significantly reduced range compared to the very same 3DR radio unit plugged into a PC and using Mission Planner.
This is very unfortunately as I was hoping to replace PC groundstations with a simple, lightweight tablet with long battery life etc etc. Does anyone have any clue as to why this is happening? Maybe something to do with how the Android USB works? I tried to use a micro to full size USB adapter in order to run a full length USB cord to put the telemetry radio higher into the air in an effort to gain more range, but the telem radio no longer worked with this wire so I suspect the 3DR supplied micro to micro USB is special for the telemetry radios.
Hi Christoph,
We are wanting to use the tables in a commercial solution at Agribotix so we want them to be foolproof. We have greatly improved the performance through a few channels.
Firstly we tested multiple tablets and some are much better than others. We settled on the Nexus 9 as it was a good priced tablet that performed as well as a very high end Nvidia tablet.
The second thing key thing we did was use a bluetooth adapter instead of the supplied USB cable. Even when powering the telem radio with it's own lipo, it still worked much better over bluetooth than USB.
Lastly we specced the Hobbyking 500mw 915mhz modules instead of the 3DR 100mw 915mhz modules and upgraded our ground antennas to a nice 5dbi L-Com omni. It's unfortunate that the hardware upgrades are necessary but in our testing that's what's required to fly 1km with good signal quality using the tablet solution.
Now give me a PC and a pair of 100mw 3DR radios and it will go 3km or more with great signal quality. I really hope the next version of Tower figures this out.
Yes we tried the RFD900 but abandoned it because it's a pain to wire and setup correctly, isn't as reliable to connect, and doesn't really perform any better than the 500mw unit with a good L-Com antenna.
check what voltage your device outputs in OTG mode when the radio is on, is it true 5v ?
I am not sure of the voltage as I haven't measured it yet, but I get the same exact performance when using an Event38 bluetooth bridge instead of the 3DR radio which has its own internal battery.
http://copter.ardupilot.com/wiki/common-3dr-radio-version-2/
good read and good luck
verify that you have correct antennas, not 5.8ghz, 2.4ghz, or 900Mhz..
you should have >1Km on stock settings.
DO NOT up output power to compensate for defective or wrong antenna, you can easily destroy transmitter transistor.
also, try telemery alone, away from a certain place or computer - some hardware can be very noisy around those freqencys.
As Steven G said, read the manual
As for the 3d radios you don't need FTDI cable to adjust radios settings, just the normal usb cable to connect your pc with the radio.
You will need Mission Planner on your pc
The supplied antennas aren't going to assist with interstellar communications, but they're not useless - I get at least 1km with them. Ramping up the power isn't likely to fix a 30m range issue but will likely break the law in most european countries I believe.
Check for loose connection of the aerial, including wires inside the case, and it's worth trying a reflash/upgrade of the firmware.
Also note that there does seem to be a small failure rate of these 433 radios, so you should ask 3dr or your reseller that you bought them from.
http://ardupilot.com/forum/viewtopic.php?f=22&t=5939
http://diydrones.com/forum/topics/only-1m-range-with-433mhz-telemet...
Steven G, sorry to contradict you but i also have telemetry problems with 3d radios, do I am using 915 and I believe rfdesign are also 915.
I tried changing antennas and install rfdesign antennas and monitor with the 3DRRadio 1.3.exe software from Michael Oborne and found that there is not much difference with the stock 3d antennas....
Shall be grateful if you could prove me wrong because it is an annoying issue this lack of range
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