Automated Candy Results

In this post, i'll describe the user experience of the automated Halloween candy dispenser we built and some of the results. In the next post, I'll discuss the prior art of automated candy dispensers and our engineering process.

We built our dispenser as a response to COVID-19, trying to find a way to keep the spirit of Halloween alive but in a safe way. I wanted a way to be able to still give out some new, wrapped candy but have it be totally contact free. I also wanted a way to minimize crowds and gatherings.

Our solution was to build an automated dispensing mechanism that was basically a large pipe which was like a magazine/reservoir/hopper of candy that was aimed into a long chute. Between the pipe and the chute was a door which was opened and closed by a motor. The motor was connected to an Arduino, which is a microcontroller connected to the Internet and activated via an Alexa Routine that I programmed. It took about 2 months of work to build and program the entire thing, going through a couple iterations (most of the work was concentrated in the last 2 weeks before Halloween).

We told our close friends and neighbors about the candy dispenser and asked them to come try it out; this was done kind of "by appointment only" to limit the size of groups and keep things as safe as possible.

Through the course of the night, we ended up serving approximately 50 portions of candy. Everyone who visited seemed pretty happy; you can find read some of their quotes and see some of their reactions below. I've also included a video showing the full experience from the user's point of view.

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When people walked up to the candy chute, they were greeted by the following sign. (If multiple people came, there were footprint stickers on the floor telling them where to stand to keep distance.) The sign explained that they needed to say the magic words "Alexa, Trick or Treat" to activate the dispenser. This was set up as an Alexa Routine to listen for that phrase. I mounted a small Echo Dot (I also considered an Echo Remote but decided to use a Dot to be able to play music out too) near the chute and connected it to an extension cord for power.

Upon hearing the magic words, Alexa would turn on a red rope light (activated via a Wi-Fi outlet integrated with Alexa) and say, "Please hold your bucket under the chute." Then, the candy dispenser would be activated, which would open its little door for 200 milliseconds to dispense a random small amount of candy. Then, a few seconds of the Haunted Mansion theme song ("Otherworldly Concerto") would play, and then Alexa would say "Happy Halloween!" I was surprised by how many people said "thank you" to Alexa even though she's a machine.

This video shows the full experience from the user's perspective.

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The night of Halloween I was grateful to receive a lot of positive feedback. It seemed like people were yearning for some way to celebrate Halloween involving candy in a safe way, and they were happy to try something new and exciting. Here are some of the kind things people wrote to me:

"It really was the highlight of Halloween."
"That was unbelievably cool. Thank you so much. Made all our days."
"That is fantastic! Lucky kids this year."
"Brilliant."
"Absolutely genius."
"This looks amazing!"
"What a great idea!"
"So fun!"
"You guys saved Halloween!! Thanks for doing this."

Below is a short video of some of the raw reactions of happiness and surprise the little machine generated.

And here are a few photos of some of the candy dispensing in action:

Halloween was unfortunately the first time I really got to stress test the system. Previously, I had only ever run it for 5-10 minutes at a time, dispensing 10-20 loads of candy total. Surprisingly, the entire thing worked fine throughout the whole night, and it only jammed once (which was fixed by some shaking of the pipe to unlodge some candy).

There were other problems and issues I noticed when I finally had real people testing the system. While Alexa is cool and powerful, I realized the voice recognition quality outside at a distance was not great and a bit slow. People (especially kids or those with accents) had a hard time activating my Routine, and Alexa couldn't understand them. Even though I didn't have to be near the machine, I sometimes listened to what was happening and called out to people to try again if Alexa didn't immediately understand.

Also, my design made it difficult to know when the candy had run out, and i noticed some variability in the dispensing quantity from person to person. Some of the guests made jokes like "Alexa seems to like you more than me." I also realized that I didn't have a large enough magazine/hopper since it could only do about 20-25 dispenses before running out; while this was ok for this year's Halloween, for a normal Halloween of 100+ kids, that wouldn't work well.

Overall, the night went well, and I learned a lot about what worked and didn't work and what could be improved in the future. Overall, it was very satisfying to see other people enjoying something we had built, laughing and having a good time.

In the next post, I'll go through some of my candy dispenser research and engineering process and design decisions.