Water Detection Project

Alright, so I am totaly new to the wonderful world of Arduino, despite having drooled over many different projects I have seen, I have not done one.

I am tempted to try a project, I realize it would be dificult, but am curious of the feasability, so here it goes:

I want to have a system set up in my home that has multiple water detection units, all connected wirelessly (Wi-fi seems like the best option), to a centeral hub (the heart of the system, arduino of course :D ) at my water intake line (or somwhere that all my water flows through), with a servo controled valve to shut of my water if one of my satelite units detects water. I would also like it to contact me via mobile (so basicly twitter, which I know has been done and well documented).

Now for the problems I am seeing:

The first is battery life of the satelites (Wireless water sensors, but I shall call them Satelites for the remainder of the project). How would I be able to make this project so the battery's could last at least 6 months (anything less than 4 is a pain :| ) and yet still have a wireless system? Would I be best not to have an arduino board at each sensor? If so, how to connect it back to the main hub?

Next is the wireless problem, as briefly mentioned above. What would you fine people recomend as the best option to connect my sensor ( a simple schematic) to a wireless transmitter which connects to the centeral hub? This is where I am really conncerned, at the moment I am looking at the option of having an ard board with a wi-fi shield connected to each sensor, but this is hardly a cost efective method.. Any brilliant suggestions out there?

Finaly, just any genereal input would be appreciated before I venture out into the world of Arduino.

Cheers,

Rich

PS, I am quite competent with circutry and genereal programming (and am well aware that this is no simple newb project).

How often should the satellites check for water? Once per day?

What should happen if the batteries of a satellite die prematurely?

Instead of checking for leaks at several locations, wouldn't it be more practical to check for any water flow when no water flow is expected?

If you are that concerned about a water leak, shouldn't you just turn off the water outside the home?

for the wireless section: Sounds like an ideal case to use Xbee units; google 'xbee arduino'. They have low power consumption (1 mW to 50 mW, based on which model you pick), and depending on how frequently the data from your sensors are transmitted, they can be put to sleep during idle time to make it for the 6 months you desire. Easy to use; and Xbee-Arduino combos are popularly documented.

The Xbee is already a system on a chip and it has digital input and output pins and also analog input pins, so using one to monitor a few sensors doesnt require an Arduino, in fact using one arduino connected to one single sensor and an Xbee is a total nonsense.

in fact using one arduino connected to one single sensor and an Xbee is a total nonsense.

Can you put the XBee to sleep, and wake it up at appropriate intervals (whatever is appropriate), without using an Arduino with each XBee?

I think Jeenodes might be good for this. They have built in wireless and IIRC really low power.


Rob

PaulS:

in fact using one arduino connected to one single sensor and an Xbee is a total nonsense.

Can you put the XBee to sleep, and wake it up at appropriate intervals (whatever is appropriate), without using an Arduino with each XBee?

Hi Paul, Yes, the remote AT command “SM” does the job (API can also be used as you probably know)… the remote command being sent from a remote Xbee that IS connected to a microcontroller.

And @Senso: Definitely not nonsense. While the XBee’s self-sufficient capability is part of what makes it so versatile, I can also on the other hand think of at least 3 situations where an Xbee-Arduino (or Xbee-and-microcontroller combination in general) would be useful even in a single-sensor project. E.g. ANY processing, time-based or otherwise, that needs to be done with the data before it’s sent. Or for storage of the data locally, backup or otherwise, for cases where the receiver Xbee is not within range. Or for higher-accuracy analog-to-digital conversion needs from the sensor signal.

[quote author=Coding Badly link=topic=65780.msg481932#msg481932 date=1309938021]

Instead of checking for leaks at several locations, wouldn't it be more practical to check for any water flow when no water flow is expected?

If you are that concerned about a water leak, shouldn't you just turn off the water outside the home?

[/quote]

I think Coding Badly's advice should be considered. It could work out much more efficient to have some kind of single water flow sensor on the main water line. Then a valve that could shut off the water if the Arduino deems necessary because of high flow rates.

phishstik: [quote author=Coding Badly link=topic=65780.msg481932#msg481932 date=1309938021]

Instead of checking for leaks at several locations, wouldn't it be more practical to check for any water flow when no water flow is expected?

If you are that concerned about a water leak, shouldn't you just turn off the water outside the home?

I think Coding Badly's advice should be considered. It could work out much more efficient to have some kind of single water flow sensor on the main water line. Then a valve that could shut off the water if the Arduino deems necessary because of high flow rates. [/quote]

This would be great in a situation where the water system is not in regular use, but I was hoping to be able to have it set up in my home, I have been through a flood, and I was just out for the day. They suck.

I have been through a flood, and I was just out for the day. They suck.

Ours was at least four days of continuous water flow from an open pipe. 1/4 of our house was completely gutted. 1/4 of the house had no damage. The rest was severely damaged. I feel your pain.

If you are trying to detect an "open pipe" failure, a simple pressure sensor will likely work very well. A modern house has water restrictors at every opening. As a side-effect, when water is flowing, the pressure in the system will remain close to what it is with no flow. An open pipe, on the other hand, will result in a significant pressure drop.

But I can understand your desire to detect leaks in-situ.