The labs continue to get more complex as the semester goes along. In this lab I sent data from two photoresistors to Processing through Arduino. It took a while to work out the kinks in The Call and Response Handshake Method but overall, was a success.

The processing reference came in very handy for understanding the microcontroller code. I frequently found myself looking up definitions for data types like ‘string’ so that I could fully understand all of the arguments. Shwew. Processing grabs the sensor data generated by arduino from the serial port and graphs it.

Goal: In this lab, you’ll send data from a single sensor to a program on a personal computer. Graph a sensor employing serial output.

What is happening-> This is a common way to find out how a sensor’s output corresponds to the physical events that it senses

How to graph a sensor employing serial output:

Prepare breadboard. Connect touch sensor to breadboard and Arduino analog pin 0

Program Arduino to send and read the analog sensor and print results via ‘Serial.write’ to the serial monitor

Observe jibberish %%*##$# on the serial monitor

What is happening? “Serial.write” cannot format bytes as ASCII characters. Instead it conveys the binary value of the sensor reading.

Observe serial data in bytes and hexadecimal view-> download CoolTerm

Close the serial port to observe serial data in bytes and hexadecimals

Graph the potentiometer’s values

Import Processing Serial Library

Program Arduino

Observe touch sensor’s values graphed

 Tone output

The second part to the week 4 lab is to generate tone output. Tones, pitches, and…

How to program the microcontroller to produce a melody:

First put Pitches.h into a tab

Declare two global variables in the code-> Make arrays with pitches.h

The first array holds notes-> The second array holds note duration

Enjoy the 8 note tune…

This lab was satisfying. I discovered that I really enjoy making things move.

Goal: Control a servomotor’s position using the value returned from an analog sensor

How to program the microcontroller for the servo motor:

Find the range of the sensorà Initialize an analog read

Map the result of the analog read to the range of the sensor in degrees from 0 to 179

Stored the value of the reading to a local variableàCall it servoAngle

Add the servo library at the beginning of the code

Make a variable to hold an instance of the library, and make a variable for the servo’s output pin

In the setup(), initialize the servoà Use servo.attach()

In the main loop, set the servo position withà ServoAngle

Servo Motor Code

<–bad signage

This past weekend I traveled to Milwaukee for a wedding and was struck by the inefficiency of airport security in NY. Ugh—need I say more? Waiting in the security line at the La Guardia airport is particularly lengthy and dreadful even at 5 am on a Friday morning. For my recent physical computation assignment I chose to observe and comment on the airport security experience provided by TSA (Transportation Security Administration) at the La Guardia and the Milwaukee, Wisconsin airports.

The experience of going through airport security adds to the stress of everyday life because of poor design, poor management, and constantly changing regulations. I will occasionally hear chatter about bad airport experiences.  My most recent memory of this was the story of a woman who was forced to throw away containers of breast milk she had prepared for her newborn before boarding her flight. In my opinion, security went too far and used poor judgment by sticking to the rules.

Overall, the airport security experience is not intuitive. It may be assumed that you place your bag in a tub on the conveyor belt and walk under the imaging sensor. If you don’t trigger a beep can you just move along? Or do you have to also be scanned by the security officer waiting for you? From my experience, that moment is always a bit awkward. It makes me feel like an idiot. Do I stay, do I continue, is there a signal?

One must read signs with small print and mimic the behavior of the person in front of them. Don’t get me wrong, I understand the importance and need for airport security. Airport security procedures, especially since 9/11, trigger plenty of debate. I believe Donald Norman, an expert on Design and human psychology, would agree that the usability, understandability, and appearance of airport security could stand to gain a mindful makeover for the benefit of all.

Often times I end up learning about a new procedure when I’m in a security line or via my mom during the car ride prior to. First it was no liquids; then 3 oz of liquids in a zip lock bag; no water bottles or Starbucks coffees (I’ve kicked myself multiple times for grabbing a coffee before I get in line); laptops must be in a separate bin, etc. More recently, people are required to take off their shoes and loose fitting over garments. Personal items must be scanned while the person walks under the advanced imaging, which uses millimeter wave and backscatter technologies.

Any potential threat items that are detected are indicated on a generic outline of a person.

If no potential threat items are detected, an “OK” appears on the monitor with no outline.

While observing the way people interact with the security technology and procedures I noticed that the more experienced travelers are total pros. They are prepared for what is expected, step right up and get out. For the seemingly less experienced, older, and younger folk, confusion ensues, and the wait becomes even longer. In these instances, the airport security operators physically and verbally direct those people that aren’t sure what to do.  My assumption is that the less experienced may read the signs, or half read them, and really don’t understand what to do until after they trudge through.

I’m not sure what the easiest part of airport security is. Perhaps handing the official identification and a boarding pass?  One of the difficulties that anyone can run into is when something unexpected triggers while walking through the detector. On separate occasions I’ve triggered the detector with my belt buckle, earrings, and boots. When it isn’t obvious what is triggering the sensor the security officer will guess, we will both look confused, and then they will tell me to move on.  Not all airports have the advanced imaging technology that passengers walk through. For example, at the Delhi airport this past spring I sent my bag on the conveyor belt and then was felt up and down by a woman behind a curtain before I could pass. I was shocked, mainly because she really felt me up.

At the bustling American airports there are two particularly long procedures involved. One is waiting in line, especially in NYC, and especially around the holidays, and especially when you are running late for your flight. The second step that will hold you up is when the security officer and the imaging system finds something threatening in your carry on bag. When this happens you have to stop; you are not permitted to touch your bag; you will be asked if anything is sharp or harmful in you bag; and the officer will unpack the bag and examine contents before they run it through the imaging machine for a second time.

This experience can be embarrassing and frustrating for people. As I went through security in Milwaukee I was stopped with my bag because something potentially harmful was detected. The officer went through the standard procedure and yet neither of us discovered what triggered the detector and I was left trying to repack my bag that was packed to the brim.  It’s very difficult to predict how long it will take to get through airport security. I’ve learned quickly to arrive extra early to airports in large cities such as San Francisco and NY.

Nothing happens until something moves

-Albert Einstein

Mick Hondlik and I collaborated on the Stupid Pet Trick project for Physical Computing. Our intention is to make the duck come ‘alive’ by using an ultrasonic range finder and a pressure senor. If you come within 2cm-3ft of the range finder, the duck’s eyes turn blue. If you move too close to the duck then the eyes turn red. Try picking up Cyberduck and his eyes turn green.

For the second part of the project we are using a similar interactive concept but with 3 different mp3 clips. The three clips are: a rubber ducky song, a don’t even think about it quote, and shriek noises.