Water Leak Detection Project

I am a newb with Arduino. I have a project I would like to build and would appreciate any advice on how to do this. I have a vacation house in Vermont and I'd like to be able to monitor for burst water pipes. My idea is to have a wireless transmitter with a moisture sensor connected to it under each sink and a few other places in the house. Ideally the transmitter would be battery powered and be able to last 6 months without changing the battery. If a sensor detects water it would transmit to a receiver connected to an Arduino. The Arduino would be connected to the internet send out an email or text message. I'd like to do this without the Arduino connected to a computer.

I looked at the XBee (I'm in the process of building tweet-a-watt), but I think they will draw too much power to last 6 months on a battery. I saw some small 315MHz transmitters and receivers on Sparkfun that might work:

If I went with these 315MHZ transmitters would they interfere with each other, or is there a way to ID them. I'd probably have 5 transmitters the house.

What would make the project even better if each transmitter also had a temp sensor connected to it. Then setup the Arduino to alert me if the temperature falls below a set point, like 38 degrees.

What I'd like to know is what hardware should use for this project? Are there other projects around that do pieces of this and thus let me use and learn from that code. Is it possible to get the Arduino to send me an email or SMS text to my phone (without being hooked up to a PC). I guess if email would work, I could just send an email to my phone and that would show up as a text message.

I'd appreciate any suggestions and advice.

--Scott

There is a pretty nice device called a Sensaphone that can monitor temp and various other inputs and can dial multiple phone numbers when an event occurs. It also detects power outages and noise levels.

It has a nickname of "cottage sitter". You could use it alone with wired sensors or hook up Arduinos (wired or wireless).

I have the Sparkfun 315MHz RF modules. It could tricky having multiple transmitters since they could talk over each other.

See reply #14 here for RF sketches for the SparkFum modules:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1249592327

If I went with these 315MHZ transmitters would they interfere with each other, or is there a way to ID them.

Yes. ;D

Having several transmitters on the same frequency will cause interference, so the trick is to design the system to minimize that, and live with it. You can do that by having each transmitter send a unique ID, send its message multiple times, and delay between transmissions to reduce collisions.

My suggestion would be to build each sender around a cheap micro like a PIC or ATTiny, that has the ability to go into a low power "sleep" mode and wake itself up with a timer and/or an external interrupt. Each would be programmed with software that's almost identical, but has a different value for its ID and the delays between repeats (depending on the chip, you may be able to use identical firmware, and put the variables in EEPROM).

By putting the micro to sleep, and turning off the transmitter, for 99%-or-so of the time, you should be able to get good battery life.

A single Arduino, with receiver and Ethernet shield, would collect the messages and send the email.

You may need to add a firewall to your internet connection, if you don't already have one: there are millions of zombie PCs out there, constantly probing every IP address on the net. The traffic may be a problem for the Arduino.

Ran

Scott,

I am looking into building a similar project notify me of water in the basement.

I was wondering if you finished this project and how it went?

Thanks,
Tristan

I had a similar concern for a property on well water. I now monitor the well pump, because that was easy to interface to. If it is running when the house is empty, I assume there is a problem! Finds leaks even if they aren't where I thought they might happen. I also monitor the temperature, and thus may someday get aid on the way BEFORE the pipes freeze. Both can be done with an Arduino, of course, which is why I've posted this here. "Off (Arduino) topic": For a related Windows specific "answer" see FarWatch- a system to monitor premises remotely- ssds043

I'm not done yet. So far I am monitoring the pulse from my gas meter and crawlspace temp - data goes to pachube.com. I want to add some wireless temp sensors then water detection. I'll post the whole project when I'm done.