Daily Archives: December 6, 2010


Hacknight Recap 2

A quick recap of the Hacknight: Due to being on call for work, I spent a good part of it just doing little things around the lab. I built us a coat rack mostly out of my scrap lumber and parts.  Also rigged us a 15A outdoor extension for back yard power and other kinda maintenance stuff.

Progress was made on a single sensor/light pipe for the Player piano music reader reader (fyi plastic light pipe does not like superglue it melts!) more on this fantastic project Ray blogged about here,

Added some new stuff to the workshop, including a propane torchhead and bottle, and the adapter tube for the large spare propane tank in back. That spark any hot ideas for you?

Speaking of that, anyone got any interest in RFID hacking?

Or,  building some sort of Electric Furnace?

Next Hacknight is Tuesday 7-10pm  come on down!


Player Piano Roll Reader Project 8

I have about 50 player piano rolls (exactly why I have 50 piano rolls is another story).  Despite the fact that most of the rolls are about 80 to 90 years old they are in surprisingly good condition.  However, I do not have a player piano to play the rolls on.

In this part of the country (the Southwestern part of the US) player pianos are very rare so getting a player piano, much less having the room for a player piano, and investing the time and expense of repairing a 90 year old instrument, is not very likely.

Today in an average living room the television is the centerpiece of the room, followed by an entertainment console that usually houses a DVD player, a bunch of DVDs, and maybe a gaming system.  In the 1920’s when most of these rolls were manufactured, there of course wasn’t television, DVD players, or gaming systems, and commercial broadcast radio was still about 20 years away.  Records were available, but records sounded tinny and were rather expensive.  So what was “must have” the entertainment machine sitting in an average living room in the 1920’s?  Most often it was a piano and most of those pianos were player pianos.

Back then, piano rolls were like CDs are today.  All of the “Top 40” songs of the 1920’s were on pianos rolls.  But just like listening to CDs, sooner or later you get tired of the music and want something new.  Back then people would go to Sears Roebuck and buy piano rolls.  Families would often spend evenings together singing songs around the player piano.  Yes, I know. It sounds incredibly lame by today’s standards, but back then they didn’t have much else as far as entertainment in the home.  The player piano was pretty much the “in thing”.

In looking over the rolls I found such interesting titles as “I’d rather forget than forgive”, “I’m gonna let the bumble bee be”,  “Can I sleep in your barn tonight?” and a few with familiar titles like “I’m looking over a four leaf clover”.   I began to wonder what music might be on the rolls – Just what did “Top 40” sound like in 1928?  What secrets have these rolls kept hidden for the last 90 years?

I decided to find out.  On Ebay I purchased a player piano “spool box”.  This is the mechanism that reads the rolls in a player piano.  I wanted to find some way of converting the spool box into something that could extract the music on the roll and send that note information to a PC.  Then on the PC that information data could be converted to MIDI.  If all worked, I would be listening to music that few people have heard in nearly a century!

Well life often has other plans and I put off the Player Piano Roll Reader Project for another day.  It sat along with a number of other neglected projects for about 3 years until I discovered Quelab.  In discussing the project with several Quelab members, there was renewed interest.  These people wanted to hear what was on these rolls as much as I did and the idea of converting 90-year-old digital information to MIDI seemed pretty cool too.

90-Year-Old Digital Data

So the basic plan is this: Put a bunch of infrared LEDs on one side of the roll and 88 light sensors on the other side of the roll and read the data from the sensors.  I chose infrared LEDs because paper is mostly opaque to IR while visible light pretty much goes straight through.

Infrared Light Bar – 50 IR LEDs Closely Spaced Together

Since the “read holes” in the spool box are too small for commonly available IR sensors, I will be using fiber optic cable to transmit the infrared signal from each hole in the roll to IR sensors on a separate circuit board.

IR Output From the Infrared Light Bar

I used my cell phone camera to capture the IR output of the light bar.  Although it is hard to see in the picture, all of the LEDs put out a strong IR signal.

The next step is to order the fiber optic cable and start building the IR sensor board.  This will be 88 IR light sensors connected to 88 fiber optic cables.

See Part 2 http://quelab.net/172/player-piano-roll-reader-project-part-2/