Nagel Family Website

I’m a geek, and was quite proud of this set-up I’ve got going on. We’ve got a hot tub outside, and during the cold Buffalo winters, if there was a problem and the lines froze, I’d be S.O.L. So through the miracle of modern technology, I’ll know if a problem is coming.

First, you need a temperature sensor for the Hot Tub. I use the Wireless Temperature Sensor with Cabled Probe. The temperature sensor is secured inside my filter, and the transmitter is mounted to the outside of the tub. Now I did have the Waterproof Floating Remote Thermometer, but they’re not really waterproof. Soak it at 105° and turn the jets on, and water gets in there.

Now you need something to grab the signal from the wireless transmitter; I’m using the WMR968 Complete Wireless Weather Station. I also have all the other sensors hooked up, including the outdoor temperature sensor. This is important… I’ll show you why later.

OK, so the transmitter is sending data to the receiver, which then feeds it into your PC. We now need to make this data readily available, which is where VWSql comes in. This handy bit of software sends the data to a MySQL database. Oh yeah, almost forgot… you need MySQL and some sort of hosting.

NOW, write a quick PHP script… get the data “select * from weather order by RecDate desc limit 1″ and check the temperature:

if (
($rsWeather['CH2Temperature'] < 70) &&
($rsWeather['OutdoorTemperature'] < 50)
) {
echo("too cold!");
} // ends
else {
echo("OK");
} // ends else from


What this says is if the Hot Tub is under 70, and the outdoor temperature is under 50, it’s too cold! Otherwise, it’s OK. This is why the outdoor temperature sensor is important, because if its 80 outside and the water is 70, that’s OK… it’s not going to freeze.

Finally, set-up a check in pingdom. I have pingdom check my page every 30 minutes, and under “Optional Settings” I set “Check for string on page” “Should contain” “OK”. If it’s down just 1 time, I get a TXT message to my phone.

So if you’ve got some unused checks in pingdom, put them to use!

This entry was posted on Friday, November 14th, 2008 at 2:41 pm and is filed under Technology. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.