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Installation

First you will need a water level float sensor.  I have included several links above to various models and styles of these sensors.  You may need to look at your Christmas tree stand and determine what type of mounting bests suites your needs and which sensor will work best for you.  The water float sensor that I am using is a part that I had laying around from an old water cooler that I had cannibalized.  

These sensors work by completing a circuit or opening a circuitry depending on if the sensor is NO (normally-open) or NC (normally-closed).  My sensor completes that circuit when the float is at its highest position meaning that the water level is full.  If you sensor works in the opposite manner that is not a problem, you will just need to reverse the trigger condition logic of the rule in the Twine configuration section.  You can use the continuity test on a digital multi-meter to determine the circuit behavior of your sensor.

Below is a photograph of my Twine connected to my water level float sensor.

Next you will need to devise a method to attach the water level sensor to the Christmas tree stand.  I used a metal "L" bracket and drilled a small hole in the Christmas tree stand (above the water line) and attached it with a screw.

You will need to make sure that you position the sensor such that the float descends from the top position at the water level where you want to be notified for a low level.  Again, this make take some trial and error and experimentation to get the level right.  

Below is a photo of the final product.

Configuring Twine 

If you have not previously performed the initial setup configuration on your Twine, then please visit this article and perform the configuration steps before continuing.

Also, your Breakout Board should already be connected to the Twine at this time.

Open a web browser and login to the Twine management web application:
https://twine.supermechanical.com/ 

Next, select the specific Twine device that you have connected to the water level sensor from the drop-down menu at the top of the screen.

Next, we are going to create a new RULE to issue notifications when the water sensor opens the circuit indicating that the water level is below the target minimum level.  (If you have any existing rules defined, you may want to delete them first.)  Use the Add Rule button to create a new rule.  We will define a Twine rule to take action when the circuit becomes open.  

The new rule should be applied as follows:

WHEN
> breakout  = "is open"

THEN
> send alert email (and/or text messages and/or twitter post)

An example of the rule I am using is displayed below.

You may also want to include a second rule that sends notifications when the water level is restored.  This second rule should be applied as follows:

WHEN
> breakout  = "is closed"

THEN
> send OK email (and/or text messages and/or twitter post)

An example of this second rule is displayed below.

After creating the rules, make sure to click the Save to Twine button at the bottom of the screen.  It will prompt you to flip the twine on its back to immediately save the new rule to the Twine unit.  Now just wait until the save is complete.  It takes around 20-30 seconds to complete.

You are done, that's all that is needed to setup notifications from the Twine. We will now move on to testing.

Testing

Now that we have everything wired and configured, let's test the system.  Fill the Christmas tree stand with water to the point where the water sensor float is in the high position and verify that you receive the water level OK email notification.

Next, drain some of the water from the Christmas tree stand to the point where the water sensor float is no longer in the high position and verify that you receive the water level ALERT email notification.

Final Thoughts

This project turned out to be a fun and simple project due to the simplicity of the Twine hardware and software.  I also expect this to be a very useful project as we head into the Christmas season.

The most complex step was finding a means to mount the sensor and make sure that the water level and sensor float were calibrated appropriately.  The Twine device is perfectly suited for this type of task.  I will use it with batteries since it is a temporary/seasonal installation.  Just remember to place the Twine device away from the water so that accidental spills don't get it wet.  The Twine is not waterproof.

Merry Christmas!

Related Holiday Projects:

>> Sunrise / Sunset Timer for Christmas Lights

 

Note:

You may be able to use the Twine moisture sensor instead of a float sensor to detect water levels.  I just did not get the Twine moisture sensor in my order and I did have the float sensor laying around.    

FYI ... I ended up having to flip the L-bracket around and lowering my water sensor so that it would be calibrated to a lower water level for notifications.  The original position would notify too early when plenty of water was still in the tree stand.

Am loving getting Christmas tree notifications via SMS/text on my iPhone.   Just add the Text Message notification to the "THEN" part of your rule to receive text messages.