Introduction: Fridge Guard: Close Door Reminder for Your Fridge

Sometimes when I take a lot of things out of the fridge, I have no free hand to close the door and then the door is just left open for a long time. Sometimes when I use too much strength to close the fridge door, it bounces off but I can't notice it. When I realize it is still open, several hours or maybe the whole night has passed by. The food went bad and a large amount of electricity was wasted.

The Fridge Guard is a close door reminder designed for people who do not notice the fridge door is still slightly open or may forget to close the fridge door. The reminder can stick on the door and one of the polar bear's hand will stick on the frame of the door, detecting whether the door is being left open and no one notices it.

It uses the Force sensor, IFTTT and Adafruit IO to gather the information from your fridge and sends a reminder to you through the message and piezo buzzer.

Step 1: Materials Needed

Electronic Components:

Adafruit Feather Huzzah ESP8266 Wifi board

Force sensor

● Lipoly battery

● 4.7K Ohm Resistors

Solderless breadboard

Breadboard wires

Micro USB cable


● Cotton balls



● Knife

● Cutting Mat

● Soldering iron & solder

Wire strippers

Flush diagonal cutters

Third hand tool

Step 2: Setup - Adafruit IO, IFTTT

Before we begin, you'll need to set up a few quick things.

Setup IO Feeds

1. Login to your IO account.

2. Click "Feed" on the left dashboard and create a new feed called "timer".

Setup IFTTT: IFTTT helps connect Adafruit IO with your phone.

1. Login to your IFTTT account.

1. Click New Applet and then "+this"

3. Search and select "Adafruit"

4. Select "Monitor a feed on Afafruit IO" and choose "timer" for feed name

6. Click on "+that"

7. Select SMS

8. Write a customized message in the text box: For example - The fridge is still open!

After setting this, every time the Applet gets triggered. It will send a notification to Adafruit IO’s "timer" feed and connect to your phone via IFTTT and send you a message.

Libraries that you need

Adafruit ESP 8266, AdafruitIO_WiFi, Adafruit_MQTT

Step 3: Circuit Diagram and Code

Use the Arduino code to test Force sensor, piezo buzzer and HUZZAH wifi board.

For the piezo buzzer, we can create a melody or just a very loud noise to make us hear it until the door is closed.

And here is the tutorial for the force sensor and piezo buzzer I used.

Step 4: Circuit Construction From Prototype to Soldered

To make your circuit smaller, we will need to solder the wire except for the breadboard.

After finishing the circuit, when there is no pressure on the force sensor for 5 minutes, the piezo buzzer will make a sound and you will receive a message that "The fridge is still open!".

Step 5: Making

I made the design and shape to fit the context. Polar bears live in cold area, so I chose this shape.

Get ready for some handcrafting! This step involves sharp tools and requires attention to detail. Using the knife to cut the Styrofoam into a shape of the polar bear. And then cover the foam with cotton, decorating it with ears, nose, arms, and legs at the end.

Step 6: Now Make Your Fridge Guard Work!

You’re all set! See the Fridge Guard work in your fridge!

Thanks for reading! I’d love to hear any feedback and comments you have. If you make your own Fridge Guard, please share your photos in the comments below.