I spooked-up a Halloween decoration using a bit of electronics.
I started off with a “hanging reaper” decoration from Wilko, which I wanted to hang outside of my house for Halloween. I really wanted to make it light up, move about and make a scary noise to scare passers-by.
I decided to embed an M5 Atom Matrix module inside the skull of the reaper. This has a 5×5 matrix of RGB LEDs, which I could use to light up the skull from the inside. I drilled some holes through the eye sockets to allow the light to gleam through here too, enhancing the scary appearance. I also mounted a small PIR module inside the skull, and a micro servo, poking out of the bottom, to which I attached strings leading to the reaper’s arms. I used a piece of stripboard to connect everything together, soldering headers for the Atom Matrix module, the servo and PIR module. That way I could disconnect everything and re-use the parts when needed.
I coded this up using the Arduino IDE, so that when the PIR sensor was activated, it would light up red, and move the servo around a few times. The result was quite scary.
To make it more scary, I decided that it needed to make a scary noise, and a flash of lightning to light it up. I couldn’t achieve this directly with the Atom Matrix module, but I was able to use it’s WIFI capabilities to send a message to a Raspberry Pi whenever the PIR sensor was activated. I set the Raspberry Pi up with a very bright LED matrix and played a sound via a Bluetooth speaker. The result is shown here: