Building a Steam Engine Costume - Part 1 of many

My son asked to be a steam engine for Halloween.

this is a rather complicated one.

Parts:

Trip to home depot to get various odds and ends to see what I can mash together.
Lots of bolts, a form for a concrete lolly column, and some metal bits.


Electronics:

• Rasberry Pi B+
• 8GiB microSD
• mini hobby speaker
• 5V audio amplifier
• USB breakout cables
• 28BYJ-48 5V stepper motor and ULN2003 Driver Board

PI has the default installation of rasbian, added mpg321, ipython, and emacs to it.

Prototyping:

First I'm trying to get all of the various ideas to work in a coherent manner, get

the PI making noise and controlling a single stepper motor.

Stepper Motor Testing/Setup:

POC code written to drive the stepper motor from my rasberry pi here: steppertest.py

I've also wired up the audio amp and speaker to my rasberry pi, it managed to work first

shot which surprised me.

Sounds: 

Next, I searched for various steam engine mp3s (focussing on the Union Pacific Big Boy which is what my son really wants). Downloaded several and trimmed some effects (chuff, bell, whistle) and converted those to mp3.

Audio Configuration of PI:

With help from http://iwearshorts.com/blog/raspberry-pi-setting-up-your-audio/

https://www.raspberrypi.org/forums/viewtopic.php?t=14966

sudo amixer cset numid=0
amixer set PCM -- -1000

sudo alsactl store

Next, I wired up the audio amp and confirmed it works as expected:

not visible, it is drawing power and audio from the PI. Sadly, I dented the speaker

in the last few years it has been hanging out in my parts bucket.

The Costume Itself:

Still proofing things out here, started with a frame

verified width and weight with my son. Next step is to cut down

the cardboard lolly column mold and proof hooking it up, then take

it out and spray paint.