radio signals

jb44

Hi I'm new to the Basic Stamp but not new to programming. I need to send a radio signal reliably up to 1/2 mile based on a condition and then receive this signal for the purpose of performing a task. So I guess my question is: is there a way to send and receive a radio signal using the Basic stamp this far? I have a Board of Education project board.

Thanks in advance.

Mike Green

You will need a transceiver (transmitter / receiver) at each end of the wireless link and the choice of transceiver and antenna will determine the range and reliability of the link under various conditions. A lot also depends on what's between the two sites, whether they're exposed or there are buildings / walls / trees / etc. between them. A Stamp could handle the control of the transceiver and the actual data sent back and forth.

You might have a look at some of the transmitters / receivers in Parallax's webstore. Digi also makes the xBee series of transceivers including some higher power (PRO) devices that, with a small attached antenna, could handle the distance. See Digi's website for further information on those www.digi.com

Post Edited (Mike Green) : 9/16/2009 10:57:36 PM GMT

xanatos

Sure can - depending on theline-of-sight conditions. I have used the XBee PRO XSC modules for this kind of range with great success. Xbees: digi.com

There are other XBee modules, but they are 2.4gHz and don't have the range that the PRO XSC does. The PRO XSC is on the 900 mHz band.

Hope this helps,

Dave X

Edit:· Looks like MGreen & I answered at the same time!

KMyers

There is a complete project on this web site doing this ham radio. You would have to be a licensed ham to use it!!

Ken N8SYG

jb44

I like the Parallax 433 MHz RF Transceiver. I believe it will do what I want. Like I said earlier, I am new to the basic stamp world. Are there any published tutorials on how to use these devices. I have a basic knowledge of electronics (real basic) and I'm a good programmer.

Thanks

xanatos

Check the range on those - you DID say 1/2 mile, yes? Those are rated for 500 feet line-of-site, I believe. My personal experience with them determined that 500 feet might be possible under optimum, unimpeded conditions, perhaps over water. Check specs carefully before spending any money!

Dave

sylvie369

Dave, I think he's talking about the new one released today:

http://www.parallax.com/Store/Accessories/Communication/tabid/161/ProductID/582/List/0/Default.aspx?SortField=ProductName,ProductName

The product page claims a range of 2500 feet. But of course that doesn't change things - if you really need 1/2 mile, a unit that claims 2500 feet isn't really going to meet your needs, because you're not going to reliably get that distance unless you have clear line of sight above any obstructions.

I'm getting at least 3500 feet from regular 2.4 GHz XBee Pro modules, but that is with a very clear uninterrupted line of sight, mostly with the transmitter in the air. On the ground I was starting to have problems at 500 feet. If you really need 1/2 mile, you're probably going to need the 900 MHz modules that Xanatos recommended.

Phil Pilgrim (PhiPi)

Here is a thread that might help:

····http://forums.parallax.com/showthread.php?p=788294

However, the antenna connector on the transceiver is likely to be a "reverse SMA", designed to thwart attempts to use other antennae.

-Phil

jb44

Thanks guys, I actually only need 1/4 of a mile, I said 1/2 to make sure I had a strong signal.

Larry~

I have gotten well over 5 miles using two sanao wireless bridges and flat panel antennas, you·will need two pinks also, so this goes well over budget. Im sure I could get 10 miles with some work and a nice size mountain·to work with.

Post Edited (Larry~) : 9/17/2009 4:36:44 PM GMT