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jonnyhk
02-15-2005, 05:22 PM
Hello

I'm new with Basic Stamp, but I see it's a very nice component for use as a datalogger. I want to make many wireless/ remote sensor, like temp, current etc.
Any have a suggest to very small transmitter low current and a resiver that can be used for read many transmitter.
I think it will be the same system as a weather station.

Thank you
Jonny K. ( Italy)

Bruce Bates
02-15-2005, 05:42 PM
Jonny -

What sort of distance are you planning between the transmitters and the receiver? Anything over a few hundred feet will probably require a license from the issuing authority in your country.

The other issue that you will have to sort out is data collisions between competing transmitters, both/all transmitting at once.

Regards,

Bruce Bates

jonnyhk
02-15-2005, 06:47 PM
Hello
No I only like to be able to messure the temp at about 50-100m

Thanks

Paul Baker
02-16-2005, 12:16 AM
there is a thread in the robotics forum already discussing this: http://forums.parallax.com/showthread.php?p=525697



remember that when a modules specifies a distance, it is light of sight distance, if your signal must go through walls or other obstructions it will reduce the modules effective range.

Post Edited (Paul Baker) : 2/15/2005 4:20:18 PM GMT

steve_b
02-16-2005, 02:47 AM
Not sure about international RF spectrums...but there are some 'experimental' bands where you don't need a license but are restricted in output power.

I think you are limit to a watt or less (definately no more than a couple watts)....but have no fear...there are guys that transmit hundreds of miles on a couple hundred milliwatts (different frequency of course).

A friend of mind recently put in some wireless units in the basement of an old warehouse building. Big thick walls with lots of reebar. Well, he couldn't pass signals through walls, but the hallways acted like waveguides. Luckily he was using some digital units so the 'echo' (or second trip) were ignored with the CRC. He had to play with latency and preamble but it worked....so long as nobody closed the door in the one room! haha

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Steve
http://members.rogers.com/steve.brady (http://members.rogers.com/steve.brady)
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."

Paul Baker
02-16-2005, 03:07 AM
868MHz and 2.4GHz are approved for use in the EU (do not confuse 868 and 900MHz, they are different bands).

jonnyhk
02-16-2005, 04:50 AM
Hello all
I also found this other forum soo I will continiu in there..

Mille grazi