Back in 2012, we presented The Mummy’s Curse Puzzle Door of Doom. It seemed like a good time to do it again. But first we need to make some improvements.
The door took a pretty good beating in its 3 hours of service the last time around. Parts of the foam sculpt needed to be repaired and repainted. For this we used an epoxy product we heard that other haunt builders use. Aves Apoxie Sculpt is a 2-part modelling compound that is easy to use and sets-up really strong.
The original control system was on a PIC-IO board, but that had been reused for another project. Since 10 years had passed since the last use of the puzzle door, it seemed like a good time to make a tech upgrade. We chose an Espressif ESP-8266 module, which is a WiFi enabled microcontroller. The ESP-8266 can be configured for 5 digital inputs, so that would be enough for the 4 puzzle buttons and 1 switch to detect air pressure.
Having a connection to WiFi allowed us to take an IoT approach to designing our system. Instead of running wires from the front porch to the attic to be connected to the Maris hardware show controller to send MIDI commands that are, in turn, consumed by the VenueMagic software show controller (Ugh), we would use RTP MIDI over WiFi to communicate directly from the door switches to VenueMagic.
RTP MIDI, also known as Apple MIDI, is typically used to wirelessly play a synth keyboard with an iPad. Fortunately for us, there are open-source libraries for the ESP-8266 to allow a MIDI message to be sent every time an “event” happens on the door.
But why stop there? We also need to know when people are heading up the stairs. For that we have our dual light beam solution. That too is on a PIC-IO that was replaced with RTP MIDI on an ESP-8266.
Things were looking up until Halloween night. By the time we got the puzzle fixed to the front door and powered-up, it was discovered that, well, it didn’t work. There was either a mechanical or electrical problem with one of the puzzle switches. 5 PM arrived and the problem wasn’t solved. We quickly pivoted to hitting our guests with some thunder and lightning when we heard “trick or treat” outside.
The only people who asked about the puzzle were high school and college students who had trick or treated in the neighborhood back when they were much younger. It was unfortunate to let them down, but really nice that people of all ages come to see what we were doing. We gave out candy to 222 kids this year and had some great conversations with a whole lot of adults.
Next year will be scary. We promise.
Tag Archives: microcontrollers
Halloween 2019: Bats
The last couple of years has caused us to undertake a review of our technical capabilities. Too much had gone wrong or become unreliable. While the theme is usually our chief concern, this year the goal was to lock-down some of the basic building blocks of our theatrical show system.
The first item was video. The video is played back on a MedeaWiz Sprite with a DMX interface. We had tried to use video last year and it failed miserably because of a bad cable connection. It was a stupid problem to have, so that got addressed. But how to use it? A quick search of Halloween related videos on the Internet results in the idea of making bats fly out of the doorway.
Creating the video was fairly straightforward, but the key to making it feel creepy was in the audio. Without the sound, the images looked a bit like a Rorschach test. They needed that squeaky sound that bats make to add context. More importantly, it needed to sound like the bats were getting closer.
To make the bats sound menacing, multiple tracks were played across five channels of surround sound. The most distant chirping sounds were at the corners of the house. Closer-up were large wing flapping sounds nearest to the stairs. The wing flapping was not a real bat sound, but the idea of a bat flying close to your head.
The last channel was placed across the street. We used long-range Bluetooth to transmit the bats sounds to a speaker in our neighbor’s yard. This is a technical advance we will probably use in the future because it really messed with people. It was fun to watch people during the first three seconds of the video where they thought: There are bats. The bats are coming at me. The bats are everywhere.
One new piece of tech that we will definitely use every year was a new light beam trigger. We have used a light beam at the base of the stairs to start the show for years, but it always had the problem of re-triggering the show when people exited. We used to mitigate this problem by adding a delay before the show could be restarted, but that works only if people arrive at given rate.
The new trigger has two light beams. This is similar to the electronic turnstiles Disney used about a decade ago. A microcontroller board was programmed to check the order in which the beams were broken so we could determine the direction of movement. Going up the stairs starts the bat video. Going down the stairs made a cat screeching sound – just because we could.
Lastly, we upgraded our speaker system. The new speakers are more weather resistant and handle a lot more power. This was needed to reduce stress as much as wanting to improve sound quality. Rain is inevitable and this year was a perfect example. It was nice to have the speakers out all day in the rain without worrying about them. It was also nice to drive the smaller speakers by the stairs as hard a we wanted to.
The video below was mixed to be in surround sound, but YouTube re-mixes it down to stereo, so you can’t really get the full effect. Next time we invite you over, make sure to ask to see the version on the home server.