Goal

• MONITOR rain
  Is it raining or not? With this information warnings could be send out if (for example) windows are open.
• MEASURE rain
  How much rain did we get? This can be used in graphs, statistics etc.

Measure, how?

• Buy a rain gauge. My RFXCOM LAN supports 3 Oregon rain gauges. Found an RGR-682 at €30 in a Belgium Webshop.
• Mount rain gauge on shed roof in garden
  • Make sure it’s levelled. (some info on how it works
• Configure HomeSeer / RFXCOM plugin
• Wait for rain… (you can’t believe how long it did NOT rain after I installed this device!!)

Hardware

• (€60) Oregon RGR-682 rain-gauge (normal price)

Monitor, how?

• Architecture: A Rain sensor closes a loop when it’s wet. Closing this loop triggers a security or sensor device (Visonic) to send out a wireless signal. HomeSeer & RFXCOM receive this signal and set the ‘Raining’ device to true or false.
• Buy a rain sensor.
• Find good spot to mount rain sensor
• Mount the sensor
• Buy a transmit device. This could be any device that can be received by RFXCOM and is triggered by closing a loop. Examples: Visonic MCT-100, Marmitek DS-90, Klik-aan-klik-uit AMST-606 (with some modifications). I used a Visonic MCT-100
• Connect to transmit device and power
• Configure RFXCOM & HomeSeer with a virtual device that indicates if it’s raining or not.
• Make info available anywhere

Hardware

• (€30) Rain Sensor
• (€10) Power supply
• (€50) Visonic MCT-100 universal transmitter

More info

Some interesting scripts are being used to predict rainfall. It’s a Dutch thread on the Domoticaforum.