Glass vs Reflective Film Smart Mirror Showdown

After upgrading my Smart Mirror from a reflective film mirror to a glass two way mirror, I thought it would be interesting to attempt a (semi) scientific comparison between the two types of mirror.

This test involves taking a bunch of pictures and rating the mirrors on a few categories. I decided to focus on transmission, reflection, and simplicity when evaluating each solution.

You can also checkout my album of comparison photos here to draw your own conclusions!

Haunted Home Automation

Halloween is one of my favourite holidays of the year. One reason for this is that it's totally optional and low stress. People can get exactly as in to it as they want. I'm also really intrigued by the perseverance of belief that there are supernatural forces at work. No matter how fact based and rational you are, I'd wager you still get a tingling feeling on the back of your neck crossing a cemetery during a wind storm all alone at night.

In other words, even if you don't believe in ghosts, you still end up scared of them anyway. The goofy costumes and haunted houses are just icing on the cake.

My absolutely favourite part of Halloween however is that DIY is deeply ingrained in the traditions. There's pumpkin carving, costume making, haunted houses in a garage, and a lot more.

Naturally as a DIY fan, I've been thinking of how to incorporate technology into a good scare. Home automation has a lot of potential here, and it pairs nicely with the smart mirror in our house. Check out the video below to see what I came up with (with some help)!

Do it Yourself

If you like this effect and want to do it yourself, a good starting point is a smart mirror with Alexa and a custom skill to run scripts. You'll also need some Philips Hue lights.

Launch a Script Using Alexa Voice Commands

In a previous post, I showed how you can build a smart mirror with an Alexa voice assistant on board. The MagicMirror software and Alexa voice assistant were both hosted on a Raspberry Pi, but unfortunately there was no obvious way to get Alexa to control the smart mirror, or deliver commands to the Raspberry Pi.

I have now found a solution that is free, reliable, and very flexible. This is done by writing an Alexa Skill that adds a message to a cloud hosted queue based on your voice command. The Raspberry Pi repeatedly checks this queue for new messages, and runs customizable behaviour based on message contents. This is not limited to smart mirror applications, or Raspberry Pis. It can be used to launch any script you want on any platform that will connect to Amazon's SQS.

Here is a demonstration, and high level overview of how it works:

and a follow up demonstrating an extension of this idea:

In this tutorial I will focus on just using this to simply turn the smart mirror on and off. Adding your own scripts should then be fairly straight forward,

The steps will be as follows:

1. Create a Queue using the Amazon Simple Queue Service (SQS)
2. Write some python code to read and write to this queue
3. Write a Lambda Function that posts messages to the queue
4. Write an Alexa Skill that calls the Lambda Function
5. Schedule a task on your Raspberry Pi to read queue messages and take appropriate action.

DIY Smart Mirror ft. Alexa

Materials

1. Computer Monitor. Buy used and look for cable inputs that point down or sideways instead of straight out. 22" recommended (I used Acer AL2216 )
2. Video cable. Whatever fits your monitor (I used HDMI to DVI adapter)
3. Raspberry Pi 3, 16GB Micro SD Card, 5V Micro USB power supply, any RPi case
4. Wood. I bought four 3ft lengths of 3"x1"
5. 8 Angle brackets
6. Short wood screws.
7. Gorilla glue.
8. Electrical tape.
9. Extension Cord with multiple plugs.
10. 50cm x 70cm Ikea STROMBY frame.
11. Gila Mirrored Window Film 
12. USB Sound Card, Lapel Mic, any USB powered speaker *

*Bonus Alexa Materials

Additional required tools/supplies are: scotch tape, a squirt bottle, dish soap, a drill or screwdriver, exacto knife, scissors, and a saw.

March 10, 2018 update: I'm currently in the process of trying out an actual two way mirror as well instead of the window film. If you're interested in this I can recommend this mirror which comes in several sizes. I'll have a post coming soon with instructions for how to mount it.

Creating the Two Way Mirror

The two way mirror is the most essential part of this build. To create this component, you just apply Gila Mirrored Window Film to any piece of glass or acrylic. This works equally well for glass and acrylic, and only takes about 15 minutes.