[OT] 433MHz remote measurement modules

kender · Joined: 09 Aug 2004 Posts: 768 Location: Silicon Valley

My question is not directly related to PICs. I’m posting this question here, because you, guys, have seen a lot of instrumentation in your travels.

I’m looking for a wireless remote measurement system that communicates at 433MHz or lower frequency. FCC compliance is not a problem, because it will be working only for one month, and it will be shielded from the outside world by a chainlink fence.

The purpose of the system is to measure and transmit gas pressure few times a minute for a month. The range is 50 to 100 meters. 4 to 6 units per base station. Of course, I can add my own pressure sensor to a system that has an A/D.

There's a hard requirement that the device shuold be small – smaller than a 9V battery

I guess, I could put such system together myself, but I’ve got a very short notice, and I will need to field this system very soon.

Could anyone recommend?

Thanks,
Nick

P.S. ...back to web search.
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Neutone · Joined: 08 Sep 2003 Posts: 839 Location: Houston

Measurement Computing make a USB stick that is a data logger. It's not wireless and I have never used one but it looks like it will log the data you are talking about.

USB-503http://www.measurementcomputing.com/pdfs/usb-503-data-sheet.pdf

kender · Joined: 09 Aug 2004 Posts: 768 Location: Silicon Valley

Neutone,

Thanks, that't a very neat logger to have in a toolbox. I am considering a logger a a design path. The problem is that I want to see the data often, but I'll have access to the logger only at the end of the month-long experiment.

Nick
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treitmey · Joined: 23 Jan 2004 Posts: 1094 Location: Appleton,WI USA

I would use a serial logger and a pair of radio modems.
http://www.maxstream.net/products/xstream/rf-modem-rs232.php

mmprestine · Posted: Sun Aug 26, 2007 7:16 pm

These are great modules for your project.

http://www.sparkfun.com/commerce/product_info.php?products_id=155

kender · Joined: 09 Aug 2004 Posts: 768 Location: Silicon Valley

mickent · Joined: 18 Feb 2007 Posts: 22 Location: TN, USA

Hello Kender, These zigbee modules are about the size of a 9v batt but operate at 2.4 GHZ. They have a built in A/D converter that you can setup with a internal clock.

http://www.maxstream.net/products/xbee/xbee-pro-oem-rf-module-zigbee.php

They are available in two power levels.
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Mick