Gents,
this is on a 2 pair cable, one pair for power, one for data. It uses Modbus protocol over RS485 line. But the technology to make it wireless is on the shelves today. I would have to research it a little, but I remember seeing all the pieces in catalogs. You can search for multi-spectrum radios. They don't require FCC licence. Prices are going to be all over the place, because many have to be explosion proof for the oil industry. The advantages of going wired are: No solar panel or battery required for the sensor, works beyond line of sight (over the hill, through a forest, around a house, etc.)
The disadvantage is, that you have to pull a cable that may cost more than the equipment.
Dialing out when value exceeds certain limit is no problem, but I haven't programmed anything to do that in over 10 yrs, so I am not sure if that capability is now included in the operating system or if it is still add on.
Other variables that can be measured? Right now only temperature, soon discrete values, like position of a switch (rain gauge). Our priority will be to get the device reliable, figure out if it dies for any reason, how will lightning affect it, etc. For myself, I will want to know sunup and sundown, and after that digital output. That way I could feed at those times, and maybe in between if the water temperature is high enough.
One nice thing about this is, that you can use pretty old computer to do it.
Meadowlark,
I thought about making a water level gauge for a long time. In the end I decided just to stick a board in the bank, with gauge painted on it, and point a camera at it. I would like to get that going this year. I plan on buying the camera at Fries, or some other discount store. The limiting factor for me, is the bandwidth. I only have a phone line out there, so I don't think that I will be able to view live video. I am going to have to set mine up to take a snapshot every so often, and look at the pictures one at a time. I can't spend the $50/month or so to keep high speed internet connection out there, so I didn't really look into the video performance that would give me.
Windows XP now includes Remote Desktop Connection software, that you used to have to buy separetely. When you connect your home computer to the remote one, with the camera connected to it, it will be as if you were sitting in front of the remote computer, just slower. This capability is not enabled by default, but any computer savvy friend can help you set it up. If you don't know anyone, I will gladly help you.
The technology available today at reasonable prices is truly amazing. But we are cheap, and in our case it didn't do exactly what we wanted. That is why we are doing this. That, and to learn how to do it.
