In previous articles we used the the Twine device to issue notification email alerts and SMS text messages for water leaks and low water level conditions by using external sensors.  In this project we will use the twine to send SMS text alert messages if a garage door is left open for an extended period of time.  This project can serve as an electronic reminder that the garage door has been left open.   This project uses only the twine with its built in sensors, no external sensors needed.       

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Installation

The installation is quite simple.  All you need to do is attach the Twine unit to the garage door.  I used the hole that is provided on the twine and a single 6-32 x 1-1/2" machine screw to attach the twine to the garage door just under the garage door opener connector arm.  

I placed my Twine on the top panel of the garage door; however, if you open leave the garage door slightly open for your pets to come and go, then you may prefer to place the Twine on a lower panel.

 

So, basically the way this will work is than when the garage door is shut, the twine will have an orientation of "BACK".  

 

 

 

 

 

And when the Twine has an orientation of "BOTTOM", this indicates that the garage door is open. 

 

 

 

 

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.

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 twine's orientation is on "bottom" for at least 5 minutes indicating that the garage door is open.  (If you have any existing rules defined, you may want to delete them first.)  Use the Add Rule button to create a new rule.  

The new rule should be applied as follows:

WHEN
> "orientation" changes to "bottom"

THEN
> send SMS text message (and/or email and/or twitter post)

Also make sure to define the number of seconds for the trigger time and reset time under the "Options" section of the "When" trigger.  I am using 300 seconds which is 5 minutes.  So the garage door must be open for 5 minutes before triggering the notification.

Below is rule I am using:

 

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 mounted the Twine to the garage door and configured the logic rule, let's test the system.  Simply open the garage door and wait the configured delay time, five minutes in my case, and you should receive the text notification (or email / or tweet).

Final Thoughts

This project was the simplest Twine project I have put together thus far.  The fact that the only needed sensor is already embedded inside the Twine hardware meant that the only installation step required was just to mount the Twine on the garage door.  This project is a very useful electronic reminder for your garage door.  

You could also add (with the Twine breakout board) an external switch to act as an override for the cases when you purposefully want to leave the garage door open for an extended period of time.  Just add the switch and add an "AND" condition to the "WHEN" part of your rule to include the breakout condition.

Bill Spencer (via a discussion thread on the Twine forums),

Suggested instead of using a machine bolt inserted from the front with a nut attached behind the metal garage door that is may be better to thread the bolt from behind and use a wing nut to tighten down the twine from the front to make it easier for battery replacement.  

http://community.supermechanical.com/index.php?p=/discussion/comment/282#Comment_282

I agree 100% that is is probably a better approach to accomodate battery replacement.  However, you may need to use a #4 bolt and wing nut instead of a #6.  The #6 machine bolt is roughtly the same size and the hole in the Twine device and is too tight of a fit to allow it to slide on and off very easily.  

Below is an illustration of what this would look like:

* It has been noted that a #3 metric machine bolt and wing nut also fit the hole in the Twine.  Availability of a #4 SAE wing nut in local stores my be limited.

A new article that demonostrates using actual garage door (magnetic) sensors and connects two doors to the Twine.

Twine - Garage Door Monitor (Revisit)

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