The opening to Raiders of the Lost Ark has to be one of the best sequences in the history of cinema. The fantastic low-tech booby traps. The John Williams score. The visceral feeling of danger with icky spider webs is completely immersive and “completely immersive” is always the goal for us.
Spoiler: No, we did not roll a 30-ton ball down the stairs. But we thought about it.
One of the first hints we had on achieving this was in finding a still-frame of the idol room which we edited the pedestal out of. This we projected on the house so that we didn’t need to build the whole room. Falling rocks were animated over the image to simulate the destruction of the temple, triggered on a Sprite video player.
The pedestal was fabricated out of wood and carved foam with foam hardener. In the center was a pneumatic-driven lift mechanism with a Chachapoyan Fertility Idol that we bought on Etsy. Turns out you can buy anything on Etsy.
As an almost last minute addition, we introduced an ankle blaster on the stairs to simulate the blow dart scene. The compressed air blast worked really good as a scare because it was combined with a stereo blowgun sound effect that panned across the stairs. As in past years, the whole show was run on VenueMagic software.
In all, we had just over 200 kids. We’ll call it a “rebuilding” year. It was definitely the best prepared we have ever been with the setup mostly done at 3pm. Having friends Suchi and Sarath over to hand out candy also made the evening the easiest and most enjoyable we have ever had.
Writing the title in French is a poor attempt at classing-up this year’s Halloween theme. You will quickly see past that because this year we leaned in hard on childish humor. There’s no covering it up.
2020 being what it is, it seemed problematic to do something scary. Not that a good scare would be inappropriate. It seemed inappropriate to do the expected or the usual. In a year when nothing is usual, it felt like a little levity was needed. To that point, we give you The Little Pooping Dog.
We had already started building our intended theme: A highly interactive multi-media display with several tactile components. Then it sank-in that anything involving touching wasn’t going to fly. Moreover, Halloween itself was in question. Putting more time and money into a project that would encourage people to group together seemed misguided. Then we saw the candy chute.
Some genius came up with the idea of simply sliding the candy down to kids through a pipe. Not only is sliding the candy more civilized than chucking the candy at them or using a slingshot, the pipe itself can be decorated to make the method of transport more festive! But how to decorate?
At some point we were talking about just putting out a talking skeleton from our last use of a talking skeleton and calling it a day. Never mind that it’s a pirate skeleton. We are way past helping people make sense of things. But what if the skeleton pirate had a skeleton dog with him?
Why this made sense at the time no longer matters. The fact that a skeleton dog could easily be acquired and that the dog was able to straddle the pipe such that the dog appeared to be crapping out candy, appeared to us like comedy gold.
By the way, a wiener dog? It just doesn’t get any better and the suggestion for temperament from more conservative advisors was justifiably ignored.
Let’s get down to brass tacks. If the pirate is going to talk, the dog needs to fart, right? The pirate had already been wired-up with an Adafruit Audio FX sound board. Luckily, the sound board could be programmed to take triggers from more than one input, so it could have one sensor for activating the pirate spiel and another sensor for detecting the passing (out) of candy.
The light weight of the candy put into question the use of a physical limit switch. Since we were already using a retroreflective light sensor for the pirate, it seemed reasonable to use a short-range light sensor for the candy.
By now you’re probably already seeing a problem. The sensor has a reset time of <2.5 ms. The Audio FX board requires a 200 ms pulse to activate playback. If the candy is moving at 2 m/s, a typical “fun size” candy bar is going to pass over the detector for only 20 ms. What we need is a pulse stretcher.
Fortunately, we had an old Olimex PIC-IO board laying around that could be programmed to turn 20 ms pulses into 200 ms; thus, ensuring that each candy bar would trigger the audio. Sure, we might have gotten away with using a capacitor and a couple of diodes, but we are software people by trade and using the microcontroller made absolute sure the dog would fart.
Over the course of the night we got 140 kids – about 100 short of a typical night. Still, it was great to see that many people out in the fresh air. The danger is real, but our neighbors were committed to find safe ways to trick-or-treat. For the parents and kids that ventured out, we hope that the laugh was worth as least as much as the candy.
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.
