IFTTT Example: Skylight Opener with Rain Sensor for Quick Closing
This is the first article in this series about creating an IFTTT rain sensor monitoring system for a motorized skylight opener.
This is done using the BroadLink® HA-RFIRW-5V automation hub phone app that controls our skylight/window openers, blind motors, smart film, drapery motors, and many other devices, such as fans and LED lights.
In this article we will be discussing the rain sensing system applied to a typical example of a motorized skylight opener, such as the units you see in the picture at right.
This customer used 2 actuators as his skylight was particularly heavy, but the extra weight could have been offset by counter-balances, springs or gas shocks. A single wireless rain sensor can be used to trigger the closure of multiple skylight motors (and windows), and each skylight can have a wireless magnetic sensor that will detect the closure action and report the status, just in case a component fails.
There are 5 main components to this system; the first 2 items are included in the BroadLink® SK1-WIFI-AC security kit:
- The DW-RFISM-3VB wireless door/window open detection transmitter
- The TR-RFISMW-AC transceiver hub that contains the IFTTT event reaction program that triggers the BroadLink® hub
- The HA-RFIRW-5V BroadLink® controller hub that activates the skylight actuator motors by transmitting a radio signal to the actuator receiver
- The WTK-12v-RR actuator kit (contains actuator, remote control, receiver & power supply
- The RS-RFISM-12V rain sensor
If you didn't see the previous article series about using our HA-RFIRW-5V controller hub for home theater, you may be interested to review that series as this IFTTT rain sensor is an add-on to that system. You can also see more info about our motorized skylight/window actuators here.
The RS-RFISM-12V Rain Sensor
There are various different types of rain sensors on the market, and many of them are designed for blocking the operation of irrigation systems.
Most of those designs are not suitable for this application because they measure the conductivity a sponge or porous material to determine that it is raining, and it takes a perhaps 5 to 10 minutes for the sensor to accumulate enough moisture to trigger the rainfall detection event.
This works fine for irrigation purposes, but we need a much faster acting sensor for skylight closure. The metal surface detection plate of our RS-RFISM-12V rain sensor causes a trigger signal to be activated in less than a second, as soon as even a single drop of rain hits it.
This fast acting response insures that your skylight will close quickly, as soon as it starts to rain, triggered by a digitally encoded signal transmitted from the sensor to the transceiver hub. The rain sensor unit is powered by 12v DC (red+, black-), and the output (yellow, white wires) will act like a normally open relay (electronic switch), closing the circuit when rain is detected.
The optimum mounting angle is about 15°, to allow droplets to run off when it stops raining, and the output will swing open once the detection surface is dry, triggering another signal that can be used to open the skylight again, depending on environmental conditions.
The DW-RFISM-3VB Wireless Door/window Open Detection Transmitter
The on/off switch signal from the rain sensor has to be detected by the automation hub in some way, and our DW-RFISM-3VB magnetic door/window transmitting sensor provides an easy way to accomplish this.
This is normally a two-part switch; the smaller part on the right contains a magnet, and the magnetic field is strong enough to cause a small reed relay to latch and close inside the larger unit - when it is in close proximity.
One part is mounted on the door or window, and the other part is mounted on the frame, so that when the door or window (or skylight or any other object) is closed, the magnet is close enough to activate the relay. When the door/window is opened, the magnet is moved away from the relay, triggering a digital radio signal which is transmitted to the TR-RFISMW-AC transceiver hub.
For this application of rain sensing, we will discard the magnet part and solder the output of the rain sensor to the reed relay terminals inside the main body of the door-window sensor. When the rain sensor detects water droplets, it will close the circuit, emulating the reed relay behavior, which will trigger a 'window closed' radio signal to be transmitted to the transceiver hub.
You can open the main body of the door/window sensor simply by pressing the exposed tab; the back cover slides off. There are 3 visible screws that hold the circuit board in place; use a jeweller's screwdriver to remove the screws and lift out the circuit board. This exposes the reed relay, so you can solder your wires to it, but it also might be time to phone the geek.
The TR-RFISMW-AC Transceiver IFTTT Hub
This unit is the "event reaction" hub that receives the RF signal from the wireless transmitter that the rain sensor triggers.
It is where the IFTTT (if-this-then-that) software resides, with a very user-friendly phone app to configure the event reaction commands.
It can communicate via Wifi with the controller hub, instructing it to issue motor control commands or any other device you would like to control.
This unit is AC powered and just simply plugs into any available outlet, and the antenna should be left in the vertical position.
It will only connect to your router using the SmartConfig™ method; there is no alternative AP mode. Just enter your router SSID and password credentials and it will connect. We will cover the software setup in a subsequent article.
The HA-RFIRW-5V Controller Hub (not pictured)
If you didn't see the previous article series about using our HA-RFIRW-5V controller hub for home theater, you may be interested to review that series as this IFTTT rain sensor is an add-on to that system.
The WTK-12v-RR Actuator Kit (not pictured)
You can also see more info about our motorized skylight/window actuators here.
Where To Go From Here
The next article discusses the software setup of the IFTTT (if-this-then-that) alarm hub transceiver configuration, and the inclusion of the door and window opening sensor which will be re-purposed as a rain sensor input to the system.
Buy These Products In Our Online Store
If you are interested, you can purchase these products in our DIY online automation store.
Articles in this Skylight Rain Sensor series:
Part 1-Motorized Skylight Rain Sensor: Introduction (you are here)
Also, see the follow-on series about our other companion devices: