Have you ever went to get something out of your freezer only to find it has been left open, it is completely iced up and all of the food is thawed out and starting to spoil? Wouldn't it be great if your freezer sent you a text if it got left open? Well, now it can.

What it does

The FreezerMonitor is a custom circuit board that plugs into the Adafruit WICED Feather Arduino compatible board. The Freezer monitor connects via WiFi to the Amazon IoT to let you know you have left your freezer door open.

How I built it

I started by building it on a breadboard and doing the programming on my home PC. After I got it working I built out the schematic using Eagle and had a custom PC board manufactured. I soldered it together myself.

Challenges I ran into

Originally, I wrote the software for an ESP8266 uController board. It connected to WiFi and used SMTP directly and send e-mail using my ISP's e-mail server. However, the implementation was slow and not well suited to a micro-controller. Also, the SMTP was not encrypted and therefore the whole thing was terribly insecure. So I upgraded to the WICED and got access to AWS IoT. The encryption and mutual authentication is the basis for a much more secure connection. And by off-loading the messaging to the AWS Cloud the code on the uController is much simpler (and therefore more reliable).

Accomplishments that I'm proud of

I'm particularly proud of the custom PC board. This was my first foray into electrical engineering. It makes for clean professional looking hardware. I'm also very pleased with the upgraded security that came from moving the project to AWS IoT.

What I learned

During develpment I learned lots of great new skills

  • Configuring Amazon IoT
  • Hooking up IoT to Lambda to automatically trigger functionality on messages from my FreezerMonitor
  • Using Amazon SNS to send e-mail and text messages

What's next for IotAppChallenge

For the IotAppChallenge I'm excited to share my invention with others and perhaps put together a video to show it off.

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