Long distance comunication

noobmuncher

Hello,

I am working on an ever expanding robot and I would like to add wireless control to it. By this I mean I would like it to be able to communicate between the robot and my computer. I need it to be a wireless connection, but I require it to be able to have a range of 3 kilometers (1.8 miles). Does anyone have any suggestions or ideas as to how I can achieve this?
Thanks,

Mike Green

That's difficult (and expensive). Most of the short range solutions are low power and line-of-sight. You can't increase the power enough without getting a license and the frequencies involved require directional antennas and literally a direct view.

That said, there are some WiFi systems with that sort of range like:
radiolabs.com/products/wireless/antennas/2.4gig/long-range-wifi-kit.php. Do a web search for "long range wifi".

Other options include getting an amateur radio license, then using a 2M walkie-talkie with a packet modem at each end.

Another possibility would be to get a cell phone/modem designed to be used with an external controller and using the cell modem for communications. SparkFun has some modules and breakout boards: www.sparkfun.com/commerce/categories.php?cPath=66_69.

Ugha

I did a little research into long range wireless as well. I think Mike's right that cell phones are about the best bet you'll have.

Want to share why you need such a long range?

stamptrol

There are numerous unlicensed, FCC/IC approved data radios, one of which is from Maxstream (now called Digi). They are available in 100 mW and 1 watt power ranges. They are really easy to interface to the Stamps.

In the applications I've done, we were transmitting two-way data at 9600 and below. With reasonable line of sight, the 100 mW can work at a couple of miles, the 1 watt can get out there 5 - 7 miles. Special antennas can increase that to 30 - 40 miles but the antennas are very directional.

Mouser, Digikey, B&B Electronics all sell them. As Mike pointed out, they are more expensive than a piece of wire. You'll be looking at about $300 - $400 per transciever by the time you get an antenna and cables.

Cheers,

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Tom Sisk

http://www.siskconsult.com
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noobmuncher

Lol yeah i am looking into communicating from my high school (3.4 kilometers away) to my house wirelessly. I am rigging my house to be almost fully automated as far as security and roving robots goes. As well i also want to start looking into my next project which will be a self controlled flying or possibly blimp like robot. That is why i need a long range wireless solution.

As far as the cell phone module goes, can some one explain that to me please? I don't really understand how it works, what it is, or how i would be able to interface with a basic stamp.

Thanks

Mike Green

Look at the SparkFun page. They have a worked example of a weather station. Most of the communications with this cell phone module is via serial I/O (SERIN / SEROUT). You need voltage translation from the 5V logic of the Stamp to the 2.8V logic of the module. The manufacturer's hardware manual has an example of the circuitry needed.

noobmuncher

Okay I will look into it thanks

Ken Gracey

I've got an approach that will achieve your goal. Obtain your amateur radio operator's license and use handheld radios with this product http://www.tigertronics.com/rtx12.htm

Depending on obstructions, repeater access, antennas and radio setup this distance may or may not be a problem.

Ken Gracey