Step 3: Circuit Design

There is nothing especially complicated about the device itself. Full schematic could be found here. Attached to the step is a simple diagram that explains basic components.

It was not trivial to put everything into a small box. Since I wanted to manufacture everything at home, multi-layered circuit design did not quite work. So, I had to fake a multi-layered board with an Arduino shield-like circuit. Blue lines on the attached schematics represents bottom layer, red lines are connections via shield headers.

I used photoresist method to etch the actual board. 
<p>Could you share the circuit draw in pdf? THX</p>
Any chance I could buy the circuit board for this? Or the completed circuits? We are designing an escape room and a box that opened by music notes would be amazing! We have been looking for something like this, but it just doesn't exist commercially. We would pay you for you time. Thanks in advance.
Did you have any luck finding someone to sell you one of these? I too would be interested in building one
<p>cool i did one of those escape rooms the other day! where is yours? and were u able to build this box ? was it hard. teaching my niece piano, wanted to make/get something like this for her.</p>
<p>I made the box :L (:L is someone eating noodles with a noodle hanging from his mouth)</p>
Hi basil. This is awesome. What board board would you recommend if we didn't want to etch it ourselves?
if i played that tune on my ocarina not only will the box open but i can travel time. now i want to make a box like this for a mini replica of the master sword
oh and awesome tutorial btw..
The schematic and board files seem to be corrupted, unless they aren't Eagle files.
That's odd: I just downloaded them and it opened fine. I am using Eagle 6.1 on OS X.
I was unable to open these in Eagle 5.7, so I updated to Eagle 6.2 and still had the same error. <br> <br>&quot;Error: <br> <br>line 6, column 6: This is not an EAGLE file.&quot; <br> <br>I opened and read the html of the files. They are Eagle files alright. <br>I've tried this on few machines now, all with an updated Eagle, all fresh downloads with the same results. <br> <br>I'm new to Eagle, so perhaps I've overlooked something?
Thanks. They don't open in Eagle 5.3.0 which I am currently using.
What software did you use to design the laser-cut parts?
Inkscape. It is a pain to use on OS X, but I found it to be the only free alternative.
Thanks again. I heard of Inkscape, I was going to use it too (after I learn how).
That's a really cool idea! Never saw a song lock before! Would be really cool if the lock use a whistle recording, then you can open it up without any other tools such as the piano.<br><br>Nice work and congrats on your inventive idea!
Theoretically one could whistle the right tune to open the lock. It detects a frequency, not a recording.<br><br>Unfortunately, I am not a very good whistler, so not matter how I hard I tried I couldn't get all notes correctly. Hence the piano.
Well then I guess I will just have to try it out :)
I love this! <br> <br>I could see it being used as a tuning aid. Tune your instrument correctly, and get a reward! :-) <br> <br>As for the whistling question, could you get it to recognize the same tune in a different octave?
No, it won't recognize different octave: it is configured to detect exact note frequencies, not relative ones.
Cant see the video here at work, but reminds me of the door lock in Willie Wonka.
That's cool.<br><br>Will it work if you play the same tune on another instrument, or maybe whistle it?
Oh yeah, it should. It detects a frequency. As long as the instrument can produce the same one as the key tune, the box will open.
including voice? (singing?)
Well, in theory, yes. You would have to be really good at it: a lock will open only if exact notes are produces. If relative note relationship is correct, but starting note is not D5, the lock would not open.<br><br>In other words, if something sings or whistles D5-A4-D5-A4-B4-D5 it would open. If he produces D4-A3-D4-A3-B3-D4 the box wouldn't open.
Cool project, and +10 awesome-points for having <a href="http://zelda.wikia.com/wiki/Prelude_of_Light">Prelude of Light</a> as the lock song
Yep, that is correct. I got the idea for the tune from jigarbov, who built <a href="http://youtu.be/zrWBRv5-XWE?t=11m56s" rel="nofollow">something resampling such lock in Minecraft</a>.

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