Where: Leon Root, MD Motion Analysis Laboratory at the Hospital for Special Surgery in New York City
Who: Healthy subjects age 20-45 with no injuries in the past 6 months that affect walking. You must be able to walk independently for at least 30 minutes. You must also routinely engage in at least 20 minutes of any aerobic activity (walking, active commuting, bicycling, jogging, swimming, etc.) twice a week. You must not be pregnant, be a professional athlete, or have an illness that affects metabolism (thyroid issues, diabetes, etc.).
When: You will visit the lab once for approximately 2 ½ hours.
What: During your visit to the lab, your walking motion will be collected using motion analysis cameras and your energy expenditure will be measured using a machine that evaluates the air you breathe while you’re walking on a treadmill.
It is not known how general motion contributes to energy expenditure. The purpose of this study is to develop and validate a model of energy expenditure during walking, a commonly studied activity, that can be extended in the future to more general motions.
You will receive $50 at the end of the study visit.
Why: To help me with my PhD dissertation work!
We’re more than half way through semester at the Interactive Telecommunications Program (ITP) at NYU that I teach at – a two year graduate program that has been described as art school for engineers, and engineering school for artists. I’ve been going through all of my students’ blogs in more detail in preparation for handing out midterm grades, and am reminded of how far they have all come since day one. I also thoroughly enjoy this exercise because of the perspective the students there have and the creativity they inject into activities that might sound somewhat simplistic to others. As an engineer by training, I find it’s easy to get bogged down with theory and technical jargon behind the scenes. But the sense of wonder that is captured in the project documentation of the students reminds me why I love teaching at ITP – the students remind me to look at things from a different angle.
This reminds me of a Shel Silverstein poem. I had Where the Sidewalk Ends growing up, and my sister had A Light in the Attic. We both read them cover to cover several times, and memorized some of the poems. Here is the one I thought of:
Upside-down trees swingin’ free,
Buses float and buildings dangle:
Now and then it’s nice to see
The world– – from a different angle.
– Shel Silverstein
Halloween is a great time for some nerdy fun. Last week I got this awesome open source hardware pulse sensor for Arduino. Then I realized pumpkin hacking was coming up at my hackerspace, NYC Resistor. I remembered some creepy Edgar Allen Poe stories about a heart beating under floorboards, so I figured I could combine the pulse sensor with pumpkin hacking for a creepy combo.
After getting the pulse sensor working (they have all the Arduino and even Processing code written for you) I found a cartoonish picture of the anatomy of a heart that I could copy onto the pumpkin.
I printed out the picture, cut it out, and selected a pumpkin it would fit on. I taped it to the pumpkin and traced around it, then removed the picture and filled in the lines freehand as best I could.
Then I used an exacto knife and some old dull linoleum carving tools Shelby had (good call Shelby – genius!) to carve off some pumpkin layers to allow light through.
I tested it with my red blinking bike light and it looks pretty great, but was impossible tog get a good picture or video of. I found a piece of an RGB LED strip I’m going to use to make it blink from my actual heart rate, then have an automatic mode were it beats when I’m not attached to it.
I rarely have time for fun random projects that don’t have something to do with work these days, so this was a welcome distraction. I highly recommend hacking your own pumpkin – there are still a few days left before Halloween!
My awesome friend Stefani Bardin, who’s the new Director of Education at 3rd Ward, invited me to teach a new class there and this is what we came up with:
Here are some steps we’ll be taking in class from the code side to get up and running…
If you haven’t already done so, download and install the appropriate Mac/Windows/Linux version of Arduino on your computer from here. I’ll have Mac and Windows versions on a thumb drive as well, and we’ll start with making sure everyone has this installed. You may need to download or point to drivers (especially on Windows, depending on the operating system) so follow the appropriate getting started guide below.
Then we’ll move on to the Blink example in class to make sure everyone has a working board before we move on to the robot. If you’d like to try it on your own, feel free to check out the getting started guide for Windows or Mac.
If there are any issues with getting blink examples to run on all your boards, we’ll be looking through these trouble shooting tips while I work with individuals.
Then we’ll teach the robots to strike a pose, wiggle, and do some awesome math to create other, more predictable motions!
Strike_a_pose: try this code on both of your motors by changing the pin number from 5 to 3. Change the angles and upload them several times, and take note of 1) the angle of the shoulder when it’s down on the wood, 2) the angle of the shoulder when it’s at the other extreme before it crashes into your breadboard, 3) the angle of the elbow when it’s perfectly straight, 4) the angles of the elbow at each of it’s extremes.
Make sure to take note of which direction your motor spins as you increase the angle, and what the angles are when the robot is straight and against the board.
Now, make it wiggle. Here’s how to wiggle the shoulder motor:
Can you figure out how to make both motors wiggle at once? If you’re stuck, try this:
Now, see if you can adapt the code in this Instructable for your servo motor controlled arm.
Now, thanks to David Cummings (a student in the 3rd Ward class), you can make the Processing Sketch actually drive the robot arm! Load this code onto the Arduino, then this code into Processing. You will probably need to adjust the angles depending on how your robot arm was built.
Oh, and here’s the Robotic arm BOM.
Arduino (pay particular attention to the Forum area and the Reference tab)
NYU ITP Physical Computing
NYU ITP Mechanisms (also see Resources tab there)
Book – Making Things Move
Book – Getting Started with Arduino
Open Hardware Summit
I was invited by the awesome Jeremy Blum to give a short talk to high school students in the BlueStamp Engineering Program being held at Ramaz Upper School in NYC. The goal of the guest speakers is to spend 20 or 30 minutes giving the students either inspiration for the students to pursue a career in engineering and/or entrepreneurship, or an understanding of what it means to be an engineer/entrepreneur through your first hand experience. I intend to do both. Here are just a few slides and notes I used for the event.
Last week I was invited to give a guest lecture to a room full of 11-13 year olds participating in the Science of Smart Cities program this summer at NYU-Poly. They spent the week learning about energy, so I spent some time telling them how important understanding energy has been to my career, both in terms of robotic systems and biomechanics. I was genuinely impressed with the level of questions they asked me afterwards, and retroactively jealous of all the kids for the great program they get to be a part of this summer. Best of luck to all the students, instructors, and curriculum developers!
I posted previously (here) about an Arduino speed test I did with the Uno board. The rate that it could print the time, a comma, and an analogRead value was about 1150 Hz. I just got my hands on a Leonardo board, and wanted to run the same code to compare. The Getting Started Guide details how the serial buffer is likely to fill up fast and result in a visible lag in the serial monitor window. It suggests adding a delay, but I don’t want to do that, so I went into CoolTerm to try to read the data. The same code got me a rate of about 1370 Hz! So with this simple test, it looks like the Leonardo is about 20% faster than the Uno on this sketch. I’ll take it.