XBee Pro, Pool light controller

Hello all,

My boss's $700 LED pool light broke and he wanted me to fix it. I figured I put an Xbee in there so he can have a wireless remote control to control it. He was hoping for individual R,G,B led control so I figured this would work well. My only concern is if the Xbee will have any trouble with range. I ordered the higher powered 60 mW wire antenna, https://www.sparkfun.com/products/8742

Now as far as I can tell there are no options to run any additional wires so the Xbee is a must. It is about 5 feet underground in a glass enclosure surrounded by water and cement/dirt I assume. What kind of range can he expect with a remote? Also the pool light has 12 volts AC and a ground wire. I am a real noob with radio stuff but is there anyway to increase the Xbee range by tieing the antenna to ground or to one of the 12 volt wires with some electronics or something?

Thank you!

I appreciate your time for reading this and look forward to your posts/suggestions.

You won’t get VHF or UHF signals propagating through anything containing moisture
in any form.

(This is the principle of the microwave oven - all the RF energy is dumped in the outer
few cm of the food because it contains moisture)

so then I will have to make sure it goes through the ground. will this cause directional reception issues ? with the water blocking half of the signal? and what kind of range will I get through about 5 feet of earth and dirt?

2.4GHz through anything with moisture: not good. Since you already ordered it, test it.

I have used 900MHz Xbees in industrial applications and the limit for reliable communication was about 120 meters. There is no direct line of sight, and lots of metal.

I'm not saying 900MHz would get you 100 meters with 5 feet being underground, but I would expect it to be better than the 2.4GHz. Did you read this: https://www.sparkfun.com/pages/xbee_guide

Would grounding the antenna to earth ground (green wire) increase range? I know very little about radio, I do know antennas have specific heights for reasons but in this case would it somehow increase range? Or would this make it even worse?

No, that won't help.

so basically the 2.4 GHz Xbee did not work. It works in 1 foot of water but beyond that it doesn't would any of the 900 MHz Xbees work in this application? I really would like to know if anyone could possibly test this with any 900MHz modules or if they have done something similar in the past before I order anything or return anything. Is there any other clever ways to have the pool light communicate with the surface? All I am trying to do is send a R,G,B values to the light from above water.

Well, I don't think anyone is going to test your particular set up. However, I happen to have a spare set of 900MHz Xbee radios here, so I did a simple test. I placed the transmitter on a pole about 1 meter above the ground and drove down the road holding the receiver in my car. I went over 550 meters until the road curved, and the Xbees never lost communication.

Then I placed the transmitting Xbee on the ground behind the berm of the road, which was about 1 meter below the road grade. I then drove about 360 meters where communication failed.

"Your mileage may vary!" But I am quite sure the 900MHz Pro modules will work better than the 2.4GHz version, as stated above.

And finally, you could use get one with an RPSMA connector and put the antenna above ground. That could theoretically get you 15 mile range. Again: Did you read https://www.sparkfun.com/pages/xbee_guide