Puzzle 2013

Back in 2013, I (Nate B) created a puzzle to intrigue potential members. This wiki page exists to preserve the clues and gameplay, in case future website changes clobber the Wordpress pages that held the live clues.

Background

Early in 2013, word got around that Massimo Banzi, co-founder of Arduino, would be speaking at UMich: http://stamps.umich.edu/stamps/detail/massimo_banzi

I figured the event would attract "our people", but how to turn that into something interesting? Ever since the Red Bull Creation puzzle board, some of us had been talking about doing one of our own. With short notice there was no time to craft a PCB design, so I opted for a more traditional riddle-solving puzzle. I'd hand out the first clue (also a useful object) at Mr. Banzi's talk, and see what happened next.

The Arduino plate

I've destroyed my share of circuitry through inadvertent contact between the bottom of the PCB and metal stuff on the workbench. Rubber feet help, but what I really enjoy are little base plates, sized to fit the PCB, that just give it a non-conductive bottom. They can be super simple, just zip-tied in place. I figured every Arduino experimenter should have one, so I bought some sheets of acrylic and made a bunch (about a hundred?) of these:

And I tweeted a picture of it, so folks not physically at the talk could play along, too: https://twitter.com/ericmblog/status/322448205092642819

(Yes, this was back before we made the jump to .org) While the cutter was producing plates, I jumped into Wordpress and created the landing-pages for each of the puzzle steps.

I handed out all hundred plates at the UMich lecture, though after receiving more than a few bewildered looks from folks who didn't recognize the distinctive outline, I realized that the talk was mostly attended by art students who had never heard of Arduino before. Well, okay then!

Anyway. Anyone typing i3detroit.com/puzzle/ into their browser would land at step 1, and quite a few did:

Step 1

The page at /puzzle/ read:

  Welcome to the 2013 Arduino Puzzle! Do you have what it takes to solve all the clues? First to finish earns a month of membership! Solutions will replace the end of the URL here.
  
  FIRST CLUE:
  
  Nppbeqvat gb kxpq, jung qb lbh rnea ol vapyhqvat na neqhvab va n cebwrpg?   
  
  Puzzle FAQ:
  
  *Who?
  **You, if you’re reading this.
  *How?
  **Figure it out! It’s a puzzle, after all.
  *Help?
  **Hints may trickle out. Be social. Try @i3detroit.
  *When?
  **Until someone solves it. When that happens, this page will be updated.

Solution to step 1:

The clue text has normal-looking formatting, but unusual letters. Probably a substitution cipher, but the text is too small for frequency analysis to be very good. Maybe it's a really trivial substitution, a rotation. Maybe it's the most standard rotation, half the alphabet, aka rot13!

So, undo the rotation, and it decodes to "According to xkcd, what do you earn by including an arduino in a project?"

If one doesn't recognize the gibberish string of letters as the name of a comic, well first of all, what are they doing here? But also, they could Google it and discover that it's a comic. Googling both that term AND the word "arduino" yields the comic https://xkcd.com/730/, which contains the joke "Arduino, just for blog cred.

Aha! There's our answer, blog cred. So, as the first step instructed, replace the end of the i3detroit.com/puzzle/ with /blogcred/ and find yourself at...

Step 2

Text from the original page has been lost, but it included some congratulations to the player, and this clue:

  What conference made their 2011 attendee badge a functional Arduino-compatible board, including pads for an alcohol sensor circuit?

Solution to step 2:

This isn't terribly hard to google, and on the first page of results for "arduino badge 2011 alcohol sensor", there's http://www.notacon.org/435/notacon-badge-sneak-peek/

Well okay then. Onward to i3detroit.com/notacon/!

Step 3

The text of the page reads:

  Incidentally, their 2013 badge is a 100-in-1 electronics kit. The hacking is strong with this one.
  
  Clue:
  
  #define  xf     2864
  #define  xg     2550
  #define  xa     2272
  #define  xb     2145
  #define  xc     1912
  #define  xD     1803
  #define  xd     1703
  #define  xe     1517
  #define  xF     1433
  #define  xG     1275
  #define  xA     1136
  #define  xR     0
  int melody[] = { xc, xF, xc, xf, xc, xF, xc, xc, xF, xc, xF, xA, xG, xF, xe, xd, xD, xc, xF, xc, xf, xc, xF, xc, xF, xd, xc, xb, xa, xg, xf, xR };
  int beats[]  = { 4, 4, 4, 4, 4, 4, 2, 4, 4, 4, 4, 6, 2, 2, 2, 2, 2, 4, 4, 4, 4, 4, 4, 2, 6, 2, 2, 2, 8, 8, 8, 16 };

Solution to step 3:

Did I mention this was an Arduino-themed puzzle?

Obviously this isn't a complete program, but searching for things like "int melody int beats" finds a few versions of an Arduino program that uses data presented this way, and instructions to hook up the circuit. So whip out your hardware, build the circuit, blow the program into it, and listen to the song it plays! It's very recognizable.

Interestingly enough, the person who ultimately solved the whole puzzle didn't build the circuit at all. He just worked back from the frequencies to notes and started transcribing them onto a musical staff jotted onto a piece of paper, then read the notes and "listened" in his head. He said he recognized it after 4 notes. Very, VERY recognizable.

The name of the tune is a single word, so that takes us to /jeopardy/

Step 4

The text of the page reads:

  Did you really get this far? Email (my personal email, address removed from this archived version) with the word “backpack” in the subject line. You’ve won something, and I’ll figure out later what that is.
  
  NEXT CLUE:
  
  A strange little recipe:
  
  Blanched Almond
  +
  Mint Cream
  – 
  Papaya Whip
  =
  ??????

Incidentally, I received six such emails between April 12 and May 1. The field was really thinning out, and I was beginning to wonder if anyone would complete the whole thing!

Solution to step 4:

No electronics in this one! After all, Arduino is about interactive design, bridging the worlds of art and technology. And this clue favors the design folks...

The astute reader (or compulsive Googler) will recognize these ingredients as the names of HTML standard colors, which are equivalent to numbers, which makes it possible to solve the equation presented.

One complicating factor is that the numbers are commonly represented in either decimal or hexadecimal forms, which means there are two possible solutions, but I didn't think it was onerous to try both. One turns out pretty awkward anyway, for place-value reasons, so I used the other one. The answer is F5FBF2

Step 5

The text of the page reads:

  Okay, I’ll admit it, that one was just plain weird. This one’s easy:
  
  How many employees does i3detroit have?

And the answer, of course, is zero.

Step 6

The text of the page reads:

  Of course. We actually have 103 janitors, but we all pay dues. 😉
  
  FINAL CLUE: GC2V35E 

Solution to step 6:

One of the nerdiest reasons to get outdoors is a game/sport called Geocaching. And a string starting with GCxxxxx is instantly recognizable as such to anyone who's done a bit of it. Otherwise, JFGI!

Remember the start of the puzzle, where it says "First to finish earns a month of membership!"? Well, up 'til now the whole puzzle could be done remotely, but I didn't want to be stuck in the position of someone winning a membership they couldn't use. Locals only! So this step requires the solver to physically find the cache, which is located a few feet from i3's front door, thus proving that they are able to get to the space, even if they had never previously heard of us. Coordinates are on the page: https://www.geocaching.com/geocache/GC2V35E

The contents of the cache were considered step 7:

Step 7

Inside the cache container, among the usual geocaching logbook and trade-items, was a small locked box and a note, in case any other geocachers found it, along the lines of "This box is part of another puzzle, geocachers please leave it alone. Puzzle solver: Have fun!"

The box was locked.

There was a basic set of lockpicks taped to it.

Step 8

Upon successfully picking the lock (or defeating the box's hinge), the solver found an RFID key of the type that opens i3's door, and a note to the effect of "OMG CONTRATULATIONS i3'S NEWEST MEMBER! We've got to get you set up with a member orientation before activating this key, call (number removed from this archived page).", and that was my personal cell number.

Conclusion

Congrats Brian R, first to solve (but declined to claim the prize, saying he just did it for fun), and Mitchell D, second to solve, and i3's first member-by-prize-winning!