Door Monitor

You’ll need to affix your phone to the door to detect it opening. Place your phone on a piece of felt and cut a rectangle large enough that you can fold it over the phone with a bit of material overlapping, and with the top of the phone extending over the felt.

Next, carefully glue the side and bottom edges with a hot glue gun. Make sure the inside space remains large enough to hold your phone.

(You can build a case with cardboard, shown below).

Cut a short length of cardboard, about 4″ by 1″. Next, cut a rectangle of felt about a half-inch longer on each side. Cut the corners of the felt at 45º angles.

Using hot glue, fold and affix the edges of the felt to the cardboard.

Place your phone in the center of a piece of cardboard, making sure the top of the phone sticks out above the top edge. Line a straightedge up with the bottom of your phone and draw a horizontal line the length of the cardboard. Repeat on each side of your phone, creating two vertical lines across the width of the cardboard.

Next, measure the thickness of your phone and draw a set of lines that distance from the phone’s outline.

Remove the lower corners of your cardboard, cutting along the horizontal and vertical lines to where they intersect at the bottom corners of the outline of your phone.

Fold up along the inner lines, then out along the outer lines. This will create a box to hold your phone.

Apply tape to the bottom and corners to hold the box together, as shown.

Affix the holder to the edge of a door jam. We like to use blue painter’s tape for this because it will not damage your walls when it’s peeled off. Add the strip to cover your phone’s light sensor when it’s taped to your door. You may need to stack some extra cardboard behind this flap to make it stick out to where it is flush with the phone.

Create a new experiment called Door Tracker and start a new capture using the light sensor. Place your phone in the holder with the light sensor facing out.

When the door is closed the sensor will be covered, causing low light readings in the log. When the door is opened, the flap will be moved away from the sensor and the light in the room will cause a higher sensor reading. We can now count those peaks and even look at how long the door was open.