Monthly Archives: May 2014

Drawdio: Creating Music with Your Hands

Awhile back I saw a post from the folks at the MIT Media Lab on a little creation they called the "drawdio" (here).  This looked like a fun little project! It's an oscillator based on the classic 555 timer integrated circuit, but with a twist.  The twist is that you can control the frequency of the oscillation (tone of the note played by a speaker) by varying the resistance between two contacts.  These contacts seem to commonly be a pencil lead and your body, but as the MIT website demonstrates, almost anything can be used.



I decided it was time to build one of these, so I headed over the MAKE to get the plans.  I already had most of the parts (or good substitutes) on hand.  The battery holder and enclosure would have to come later.  I built the circuit with simple point-to-point wiring on perforated board.  The speaker is a salvaged part from a fax machine!

Drawdio No Case


I plugged the power supply in a touched the signal wires together.  The speaker let out a shrill tone and we were in business.  The next challenge was figuring out a case a final setup for the device.  I wanted this to be durable since lots of people at work and home would be playing with it.  The solution ended up being hot glue and a plastic crayon case.  I drilled holes in the case above the speaker for sound and added a power switch.  The final touch was terminal posts for the sense wires that control the pitch.

To make the sensor I just wrapped bare wire around a pencil body for one contact and inserted a push pin into the lead at the top for a second contact.  The goal is to complete that circuit and change the resistance between the two contacts.  The easiest way is to draw a graphite track on paper and make the circuit through your hands.  See the demo video below.

This is an incredibly fun project and can be very educational to the beginning electronics hobbyist or a way to get school children interested in STEM fields.  What are you waiting for? Go build a drawdio! (Kits available from Adafruit)

Why a Standing Desk Didn't Work for Me

Standing Desk Leeman

I spend a lot of time at work... probably more than is really healthy for me.  In an effort to mitigate any harmful effects that working has on my health, I decided to try the standing desk idea.  We've all heard about how sitting all day is very detrimental to your health (example).  Recently our department has been renovating offices and giving people the option of a small motorized adjustable height desk.  I was very excited about his until I found out that my office was not going to be renovated.  I looked at the standing desks that professors had purchased, such as the Geek Desk, but realized that those commercials desks are out of the graduate student budget.  I also had never used a standing desk before.... what if it didn't work for me?

After reading lots of articles online, I decided to build something like a standing desk on-top of my existing desk.  Following the advice over at "Only a Model", I made the IKEA pilgrimage and bought the required parts (a coffee table, a shelf, and two brackets).  I got back, cleaned off my desk, assembled the parts, and had my very own standing desk!  It was slightly shaky under the weight of two 27" monitors, but overall useable.  I thought my health problems had been successfully avoided.

I noticed that my feet began to get sore, walking down the hall at the end of the day was painful.  Reading more, it appeared that I needed a foot pad.  I bought the best that I could find, in fact it cost more than all of my standing desk parts!  The mat was incredibly comfortable and thick enough that I could take my shoes off and dig my toes in.  It still didn't solve the problem though.  I continued standing for weeks, brought in a stool to sit a few hours a day, but no gain.  Standing felt great, but not for 10-12 hours a day.

I noticed that doing tasks such as filling out paperwork that required focus, but not creativity were helped.  I wanted to get it done! Tasks like writing and coding suffered.  Not being able to lean back and think of the right words or the correct function call slowed me down.  Reading and absorbing papers was also difficult.  At the end of the day, it just wasn't working (another example).

Maybe if I only worked 8 hours a day, 5 days a week, things would have gone differently.  An adjustable height desk may have helped as well, but I doubt that I would take the time to change configurations more than once a day.  I ended up back at my sitting configuration with a new coffee table at home.

There are other options out there.  Several people in the department have recently purchased a FitDesk. These cycle desks look good for computer tasks, but are not intended to replace a full desk with their small surface area.  Probably the best option is to have multiple work spaces.  One standing position, one sitting position, and possibly something else as well.  That's possible if you have a larger office/cube, but a small office with 6 graduate students just doesn't have the room.

So what do I do? I've been trying to be better about getting up every hour or so and taking a short walk/refocusing my eyes at a long distance.  Maybe something like a foot roller would help as well.  What is your workspace setup like? Remember to make sure it is ergonomic!