I’ve been working on some basic aerial telemetry to/from a UAV and today we did our first flights with the UM96 RF modems onboard.
Although these things are claimed to have 500m of range, we went out to 1Km and they were still going strong – and that’s with the tiny whips that come standard with them.
When our schedule allows I’ll try to find the ultimate range, then we’ll throw a patch aerials on the receiver and see how much further we can get.
Not bad value for $39.
A little feedback - that’s what we like to hear!
We were equally impressed with the range. When it takes a GPS unit to test an RF unit, you know its got to be good…
-Nathan
Hello Xjet
Do you have the schematic for connecting the UM96 module? Because I have trouble getting it work properly so I thought it would be a good idea to compare your schematic with my mine in order to spot any mistake.
Wavemanx
Sure, what are you trying to connect it to? I’ve got one hooked up to a regular RS232 port and another connected to a GPS receiver operating at TTL levels so that covers most options.
Hi Xjet
I am trying to connect HAC-UM96 to my simple microcontroller chip- AT89C51 for transmitter and receiver respectively.
I could not get the result as I was trying to transmitt a simple character such as 5 from transmitter to receiver.
If you look at my code in HAC-UM96 - http://www.sparkfun.com/cgi-bin/phpbb/v … php?t=1875
I have been spending 8 hours trying to solve the problem and I could not identify the problem.
Your help would be greatly appreicated
Waveman
UM12
How far?
Quite actually 
200m in thick bush
600m line of sight, ran out of sight 
the road curved
Test setup.
TX sent out a sentence every 2 seconds.
UUU12345
Alternating between each transmitter
RX recieves and checks sentence then lights led corasponding to the TX.
DOes the grundplane make a difference?
A little.
Very happy for the price :)](http://i11.photobucket.com/albums/a184/asnz2005/zbf2/02/DSC00066.jpg)](http://i11.photobucket.com/albums/a184/asnz2005/zbf2/02/DSC00065.jpg)](http://i11.photobucket.com/albums/a184/asnz2005/zbf2/02/DSC00064.jpg)
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<LINK_TEXT text=“http://i11.photobucket.com/albums/a184/ … C00065.jpg”>http://i11.photobucket.com/albums/a184/asnz2005/zbf2/02/th_DSC00065.jpg</LINK_TEXT>
<LINK_TEXT text=“http://i11.photobucket.com/albums/a184/ … C00066.jpg”>http://i11.photobucket.com/albums/a184/asnz2005/zbf2/02/th_DSC00066.jpg</LINK_TEXT>