Safety and security are paramount for us in our travels around the country. Even in our former “sticks and bricks” homes, we monitored doors and windows with a home security system similar to ADT. Since we started full-timing over 2 years ago, our concerns have expanded. For instance, we have a cat that we leave in the rig when we go out. If we’re in Phoenix in July, we want to make sure the Air Conditioning is working because if it quits, the temperature in the rig would skyrocket very quickly and could pose a significant threat to our ultra-pampered kitty. We also now have to be careful about water leakage. We all know that water damage in an RV can occur much more quickly and can be much more expensive to repair than in a home.
My entire career has dealt with software development. One position I held for 7 years dealt with the acquisition, monitoring and alarming of hundreds of sensors aboard large luxury yachts. This system dealt with sensors from everywhere on the boat including doors and windows, fuel and water tanks, electrical usage, flooding, and even forces acting on the yacht due to sea state. Our goal in building our RV monitoring system was to come as close to the functionality of the yacht system as we could. That is, not only did we want sensors monitored, we wanted to be able to check on them at any time, wherever we happened to be, and if any of them were out of a range that we selected, an alarm would be sent to us IMMEDIATELY.
My first idea was to build the system myself. I started experimenting with Arduino microprocessors and wired/wireless sensors. I was able to create the functionality we needed, but I just didn’t want to devote the time to design, build, and then maintain a system as complex as we wanted. Plus I’d have to do all kinds of wiring and find space for multiple Arduinos around the rig. So I started looking for commercial solutions.
I did find some monitoring systems where you could put wireless sensors around the rig and even outside. Some had wind sensors, which I really liked. Costco sold a nice system that takes a couple of wireless sensors and display them on a picture frame type display in the rig. Those were nice, but we couldn’t remotely access data and there were no alarming capabilities. I was getting frustrated when my wife gave me a web address to check out. The address was wirelesstags.net. We ended up choosing this system because it met almost all of our needs.
How It Works
Wireless Tags system revolves around an “Ethernet Sensor Manager”. This is the only part of the system that needs to be wired. It’s a very small footprint box that takes one ethernet cable to connect to your Internet router, and a power cable that needs a 12vdc source either from the included AC adapter or, as we use it, directly from our rig batteries via a cigarette lighter type plug. Each sensor manager can handle up to 255 sensors so in an RV one is probably all you’ll need.
This picture shows a part of our electronics cabinet. The sensor manager is the little white box just below the wireless router. The sensor manager communicates with all the wireless sensors around the rig and logs that data, via your router, to a cloud based server that Wireless Tags maintains. Then you install an app for your phone/tablet that communicates with their server to get your sensor data. Their server also sends push notifications to the app whenever the sensor limits you define are reached.
The app allows us to add and remove sensors, set alarm levels, see battery and signal levels of each sensor, and even show charts of each sensor’s history. You can also specify how often the sensors are sampled. The more often a sensor sends data, the shorter the battery life.
Temperature Monitoring
The sensor type we use the most is the Temperature sensor. You can see one in the picture of our electronics cabinet. It’s the little white tag fixed to the top of the cabinet. We have these sensors in each room (bedroom, living room/kitchen, and garage.) We also have one each in the refrigerator, freezer, underfloor storage, outside (under the rig, fixed to the frame) and in each of the 3 sections of our frame, where the fresh, gray, and black tanks are located.
Door / Window Monitoring
There are two types of sensors for this purpose. The first is the angle based sensor that looks just like the temperature sensor, but monitors the angle at which the sensor sits. You can attach these to your storage compartment doors and they will alarm when the door is opened because the angle of the sensor changes as the door opens. You can set the sensitivity so that at one end, perhaps you only want to alarm when the door opens to a full 90 degrees. At the other end, you can set the sensor to alarm when the door barely moves.
The second type is the standard reed sensor you see in homes where there are two pieces that are magnetic and the alarm is sounded when the pieces are separated.
Light Monitoring
Another sensor that looks like the temperature sensor is the light sensor. You use this to monitor the light level where the sensor is located. You can use this to turn on lights when the ambient light level falls below a certain threshold that you define. You can also use this to command programmable lights, like HUE, for maintaining a certain light level.
Moisture Monitoring
The moisture / humidity sensors also look like the temperature sensors but they have a 4-5 inch water detector arm that can sense not only the existence of water but even water level. We installed these sensors in our washer tray and under each of our three sinks.
Motion Sensors
There are also infrared motion detection sensors that will log or alarm when motion is detected.
Finding Lost Items
Many of the sensor types can be used to locate lost items. Using the app, you can tell any sensor to start beeping. So attach a tag to your keys and you’ll always be able to find them.
For The Real Tech Geeks
If you want to take the system even further, you can easily connect your system via IFTTT (If This Then That) or KumoApps to talk with and command other internet connected devices like Nest thermostats and programmable AC outlets and light bulbs. Plus a lot more I haven’t even explored.
Another avenue for sensor usage is geographically triggered actions. If your app detects you getting close to your rig, it can automatically turn on the porch light. There are so many options it will amaze you.
The Wireless Tags App
The app let’s you see all of your sensor readings at once. You can set alarms to send emails or text notifications and even Tweets(!) as well as push notifications that alert you immediately to the existence of alarms. You can also peruse the history of all sensors including not only sensor readings, but events that occur like door opening and motion detection events. You will get notified if a sensor is out of range, or if the battery level gets low.
Battery Life and Cost
The sensors can individually be set to send their readings every 30 seconds to every 4 hours. The more a sensor transmits the less battery life you’ll get. No matter how often you elect to send readings, all detected alarm conditions are transmitted immediately. Our temp sensors send data every 30 minutes. Our sensor batteries last anywhere from 8 months to a year or more. The moisture/humidity sensors are sealed so you can’t replace those batteries.
The sensors cost around $25 – $40 dollars each. That seems expensive, but if you take into account the fact that there is no ongoing subscription cost and no cost for the app or using their servers, we consider the cost a pretty good deal.
Each type of sensor has different sub-types. Some can’t store data so you’ll miss transmissions when your rig is offline for any reason. Others store thousands of readings when offline and then transmit the readings when the connection returns. We like the ones with storage and we have yet to miss any readings even though our rig has been offline many times for extended periods.
When our kitchen sink was installed, the P-trap was not tightened correctly. About 9 months after we started full-timing, it began to leak when we emptied the dish water. This system alerted us immediately. That alone is worth the cost!