Make a Spooky Haunted Mirror

With Hallow'een only a couple of weeks away, I thought I'd do a tutorial on how to make this haunted magic mirror which, when activated, shows dripping blood and a spooky message overlaid on the normal reflection.

The mirror is actually a monitor with a partially-reflective mirror film (80% used in this case) placed on top of the glass, which is showing a full-screen animation from a Unity application running on a PC. When the monitor display is black, the screen behaves like a mirror. When an image is displayed on the monitor, it is superimposed on top of the reflected image.

The application is controlled by the keyboard keys 'A' and 'Z' to start and stop the animation. However, the most interesting thing about this project is that those keyboard strokes can be initiated by an Arduino, which is triggered by, say a PIR sensor or pressure pad when someone stands close to the mirror. The characters 'A' and 'Z' are sent using Arduino's Serial.PrintLn() command. However, instead of being displayed on the Arduino IDE Serial Monitor, they are intercepted by a custom Serial Keyboard Mapper application, which sends the characters received as keystrokes to any active Windows application - so, by sending the appropriate hotkeys from your Arduino sketch, you could control a media player, a powerpoint slideshow, or any other application.

More details on my Patreon page:   / playfultech