Easy Wireless Open Garage Door Monitor for 2 Car Garage

It's not safe to keep your garage doors opened and unsupervised for long periods of time. Animals can get in, nest, and chew through wood and wire. People can steal stuff. I wanted a reminder to check that either or both garage doors were closed when they didn't need to be open. An internet search showed some solutions that cost more than I am willing to pay, and some inexpensive cell phone apps that I would still forget to check without a reminder. Some instructables ran wires where I did not want them or required more know how than I have. Zoiinet's window and door sensor (https://www.amazon.com/Zoiinet-Unlimited-Programmable-Household-Appliances/dp/B0D2HMCSY6) promised to wirelessly turn on a lamp up to 130 feet away when a closet, bedroom, or similar door was opened, and it was under $25. This seemed like what I was looking for, but I have two garage doors, and I wanted to use one device to notify me when either door was opened. The Zoiinet device was not designed to do that. This describes an easy to make interface that sits on the 2 rails between the garage doors and turns on a nightlight that I pass many times over the course of the day, and when I head up for bed. If it's on, at least one of the doors is open. This instructable involves stepladders, powerful electric motors and extension springs that have the potential to hurt or kill. Be careful! Don't reach; move the stepladder!

Two-door garages are not all the same. The distance between the doors is not standardized, and there are a variety of mechanisms that raise overhead doors. Wire hangers are not standardized, either, nor are chopsticks. My 2-car garage door monitor dimensions are a function of my existing garage doors, my level of carpentry skill and what I had on hand. Hopefully, understanding my decisions will help you design your own system.

This project is designed for a 2 door garage like mine (fig. 1). It's made from old cardboard boxes, a couple of paper clamps (fig. 2), a wire and cardboard clothes hanger, Dollar Tree plastic tubing with an inside diameter of about 7.5 mm (for balloon displays) (fig. 3) and a Zoiinet window and door sensor, which is the heart of the project (https://www.amazon.com/Zoiinet-Unlimited-Programmable-Household-Appliances/dp/B0D2HMCSY6) (fig. 4). In this application, when a magnet is close to the Zoiinet sensor/transmitter, the transmitter sends a signal to activate the remote socket. When the magnet moves too far from the sensor/transmitter, it turns the remote control socket off.

Given my lack of carpentry skill, the project is assembled with hot melt glue and electrical tape, and while it has worked well for the past 9 months or so, it may still have the life expectancy of a dead man. On the other hand, it's not under great stress and does not bear much weight. If you make one out of something more durable, please let me know how it works out... or publish it here on Instructables!

The finished project sits on top of Track "A" and Track "B", as shown by the white diamond in the diagram. When the leading edge of the opening door begins to push the flap down the garage door is nearly fully open. When the magnet on the hanger cross-bar is close enough to the sensor in the transmitter unit, the dedicated night light in the foyer turns on.

The garage door sensor is made from a wire hanger, a used chopstick and 2 pieces of cardboard, each about 5" square. A 6" x 12" piece of cardboard acts as a counterweight for the sensor magnet. The size, shape and material of wire hangers is not standardized. Chopsticks come in a variety of lengths and diameters. My chopstick is about 9" long and about 1/4" in diameter. You may have to experiment to find an arrangement that works for you. Refer to figures 1, 2, and 3 for clarity.

1). Wrap a few inches of tape around the chopstick about 1" from one end. It should be wrapped thick enough that the plastic tubing doesn't slide off.

2). Slide the two 1" pieces of tubing onto the chopstick, and apply another strip of tape about 1" from the other end.

3). Center the chopstick under the hanger and apply glue. Slide each tube between the shoulder of the hanger and the tape, and glue the tubes to the end of the base (figure 2, "building the base").

4). I glued the Zoiinet magnet to the cardboard hanger tube with the arrow pointing to the hook on the hanger, and strengthened the bond by gluing a piece of cardboard over both the hanger and the magnet (figures 2 and 3 above).

5). The counterweight is needed to ensure the magnet is far from the sensor/transmitter when the garage door is closed. I had plenty of cardboard and didn't mind something hanging down in the middle of the garage. In my hanger, the hook is formed from two thicknesses of wire. I forced the cardboard in between the two thicknesses and reinforced the bond with hot melt glue. Metal washers, nuts and bolts and other hardware could also be used as a counterweight to keep the magnet away from the sensor/transmitter until the garage door pushes the hanger down.

1). I made a 17.25" x 11.75" rectangular surface out of pieces of scrap cardboard. Here's how I arrived at those dimensions: Each of the garage doors has 2 top fixtures (see diagram). Their primary function is to house the top rollers and guide them through the transition from vertical to horizontal tracks during operation. For the purpose of clarity, the right top fixture of Door "A" and the left top fixture of Door "B" will be called the top central fixtures. When my garage doors are open, the distance between the top central fixtures on the doors (see diagram) and the vertical brackets that hold the corresponding tracks (tracks "A" and "B" in the diagram) to the ceiling is about 20". The leading edge of the garage door swivels the hangar from perpendicular to the track to parallel with it, but if the base was 21" long, the top central fixture would crash into it. When the garage door is open, it is about an inch above the track. I made the rectangular surface 3.25" less than that 20" distance just to help make sure no part of either top central fixture damaged the interface. The distance between Track "A" and Track "B" is 11.75", which is how I arrived at the width of the project base. I used 2 paper clamps to hold the assembly on top of the rails and prevent it from moving around. The base only has a few things attached to it: The plastic tubing that turns the chopstick into a hinge pin and the cardboard sheath that holds the Zoiinet sensor/transmitter. The sheath is needed because tht sensor/transmitter needs to be removable for battery replacement.

2) The switch in the sensor/transmitter needs to be set to the 1527 code (see instructions that come with the sensor/transmitter). In this position the transmitter turns the radio controlled outlet on when the magnet and the transmitter are in close proximity. (The factory default setting is KS, where a magnet close to the sensor/transmitter turns the outlet off.) When the sensor/transmitter unit is in its sheath, the arrow on the unit needs to face the arrow on the magnet. You can identify where you want to mount the sensor/transmitter sheath by arranging the hanger and base as in fig. 1 and moving the sensor/ transmitter around near the magnet. When the red light turns on momentarily, it is close enough to the magnet. Mine is about 3/4" from the magnet. The light flickers again when the magnet is moved out of range.

These videos show how the interface, sensor/interface and magnet work together.

In the first video you see the nightlight that signals the garage door status and the monitor interface in a bird's eye test view. The nightlight is plugged into the Zoiinet remote controlled outlet. The receiver and transmitter are only a few feet apart. As the magnet approaches the sensor/transmitter, the light goes on. When it gets far enough away, the light goes off.

In the second video I screwed a compact fluorescent bulb into a plug-in bulb socket and plugged that into the Zoiinet remote outlet. I plugged that into a ceiling socket in the garage. This arrangement makes it easy to see how the garage door moves the magnet close to the sensor/transmitter and activates the light. When the door moves away, the magnet moves away too, and the light goes off.

Zoiinet says the transmitter will send a signal 130 feet, but they weren't talking about sending the signal through a maze of tension springs, metal supports and garage door rails. The Zoiinet manual points out that metal structures may interfere with the operation of the device. I only needed to send the signal about 40 feet and did not find any problems doing that. Your mileage may vary.

Originally, my design called for a 5" square of cardboard on each side of the hanger. In actual operation, the leading edge of each garage door did push the hanger down, lowering the magnet to the magnetic switch on the sensor/transmitter, but there was a problem. The top fixture on Door A was mounted higher on the door than the top fixture on Door B. When Door B was fully open, the top of the fixture was about an inch away from the edge of the cardboard. But during its trial run, the Door A top fixture came right up to the edge of the cardboard before stopping. If that were always the case, there would be no problem. But my doors use 30 year old technology, and the stop point could vary by + or -.5" . If the door crashed into the cardboard, it could crush the interface or knock it off its perch. I cut about an inch off that edge of the cardboard on the Door A side. You may need to make a similar modification

When the doors are open, my Door B is about an inch higher from Rail B than Door A is from Rail A. That meant that Door B did not push the magnet as close to the sensor/transmitter as Door A. The magnet was always close enough to activate the transmitter, but I wasn't sure that would be the case as the battery aged. I made a cardboard wedge, visible in the demo video, to make sure each door lowered the magnet to the sensor/transmitter.

I used paper clamps to hold the device to Rail A and Rail B. This helped prevent vibrations from moving the device.

Instead of a lamp or nightlight, the radio controlled outlet could be used to activate a tape player or other plug-in device. My concern was leaving the garage door open when I went to bed, but if you have more specific concerns you may want to have a more conspicuous signal or put the signal in a more prominent location. Whatever signal or location you use, check the Zoiinet manual to make sure it's safe.