Peanut Butter + Jelly

i know i should get some eggs instead, but im really craving for a pb+j sandwich...

Posted by ben chao at 08:05 AM | Permalink

Here's a varation of the analog lab. The basic idea is to convert analog input to digital output. I hooked up a flex sensor and a photocell both as analog input, and combine their values to determine which LED's to light up.

photocell on the left, flex sensor at the right.

rows of LEDs.....

here's the code that runs it

#define OFFSET 9 // where to start on digital out

// analog
int flexPin = 0;
int flexValue = 0;
int photoPin = 1;
int photoValue = 0;

// digital outs
int one = 9;
int two = 10;
int three = 11;
int four = 12;
int five = 13;

int index = 0;

void lightLEDs ( int to_which ) {

int ii;
for ( ii = 0; ii < to_which; ii++ ) {
digitalWrite(ii + OFFSET,HIGH);
}

}

void setup() {

Serial.begin(9600);

// digital output
pinMode(one,OUTPUT);
pinMode(two,OUTPUT);
pinMode(three,OUTPUT);
pinMode(four,OUTPUT);
pinMode(five,OUTPUT);
}

void loop() {
flexValue = analogRead(flexPin); // read the flex value
index = ( flexValue - 500 ) / 100; // convert

photoValue = analogRead(photoPin); // read the photo value
index = index + ( photoValue - 200 ) / 100; // convert yet again

// all off
digitalWrite(one,LOW);
digitalWrite(two,LOW);
digitalWrite(three,LOW);
digitalWrite(four,LOW);
digitalWrite(five,LOW);

// see if we want to light something up
if (index > 0 && index <= 5 )
lightLEDs(index);
else if ( index > 5 ) {
lightLEDs(5); // light them all
}

/* debug code
Serial.print("index value ");
Serial.println(index); */

delay(10); // halt for next loop
}

Posted by ben chao at 07:55 AM | Permalink

Image of Dick Cheney as Dr. Evil.

Earth in a box.

Composition work found on Flickr form CTaylor.

Posted by ben chao at 05:51 AM | Permalink

Walter Andrew's essay on the effects of mass reproduction - in 1964 - strangely foreshadows what is happening in the digital world today. He argues that that through mass production, art has lost its "aura" - its uniqueness and authenticity. But during his times, merely replicas were produced. Today, images and videos are completely altered to deceive the viewer. A person with just basic skills in photoshop can easily change a picture and completely destroy is authenticity. Even the media is a huge paste work of what sells and cutting out of what doesn't. It seems that as technology becomes more accessible, reality is more and more distorted. It doesn't really bother me that such practices are taking place, but it has become very important for the viewers to become active thinkers, as opposed to the mindless viewers Walter Andrew mentions in regard to film.

I find it amusing that during his times, those viewing a piece of art work would need constant focus and concentration. It seems to be the exact opposite now. When I'm watching a film, photography, or other forms of media I'm constantly thinking about its political and social implications, taking everything with a grain of salt. One the other hand, I'm viewing a painting these days, I don't need to think at all.

Posted by ben chao at 11:45 AM | Permalink

This is the setup with a pot.

The reading varied from 1000+ to 0 as I turned the meter.

The setup with a flex-sensor was more fun to play with. It runs the exact same code. One thing about this setup is you have to use a high resistor to get a reading. I used a 220 ohm resister in the beginning and the reading was around 1000 with slight variations. As soon as I changed to a 10k resistor the reading varied more, from 570 when it is straight to 890 when it is bent.

Posted by ben chao at 12:09 AM | Permalink

I've been fascinated with stikfas figures ever since they came out, so I decided to use them as a combo lock. One thing about stikfas figures is they are extremely flexible, so I thought I could use their hands and feet to create a circuit. I wrapped their hands and feet with foil and connected wires to it. You basically create a circuit by making his feet and hands touch each other. The users presses a button and the arduino pulls the circuit to see if it is complete or not. If you have a complete circuit, the green LED lights up (meaning you unlocked the combo), and if not, then the red one lights up. The coding for the project was actually really simple, since it just requires testing if the different parts to the circuit was HIGH.

The biggest obstacle for this project was how to correctly test the circuit. When dealing with dangling wires, there are often numerous ways to complete a circuit, so I had to install LED's in different parts on the breadboard to serve as traffic controller. Since LED's are diodes, they only allow current to go one way. This solve the problem where the users could break the lock just by puts all his feet/hands together. However, there are still a couple of ways to break the combo, and I've yet to figure out how to correctly test it.

Posted by ben chao at 09:06 PM | Permalink

I decided to study the self-checkout kiosk in the supermarket, because it was the most complex of all the interactions I observed. The kiosk is roughly 5 ft(l) x 3 ft(w) x 4 ft(h). The user would take his/her items and place it in an area before the scanner, and as he/she finishes scanning each item, place it in the bagging area next to it. The scanning was most time consuming part, as each time an item passes through the scanner, the user needed to verify that the item was registered. Users often needed to re-orient the item to scan it successfully, and sometimes a person would swipe the same item several times before it went through. After all the items are scanned, the user pays for the merchandise. If they used a credit card they would just need to swipe their card and sign, which was a very easy process. However, if they paid with cash, they would struggle with putting the bills in the feeder.

There was constant interaction between the kiosk and the user. The user had to operate the touch screen to indicate when the scanning of the merchandise began and ended. The kiosk was giving constant feed back on whether a transaction was successful or not - through a computer generated voice and by indicating the item on the touch screen.

There were several issues which made the machine difficult to use. There wasn't an area close to the register for the users to place their personal items, so they often put their handbags or wallets on the scanning area, which sometimes caused the machine to malfunction. Whether you have multiple persons or just one person operating the machine did not seem to make a difference, as the user would always have to scan merchandise one by one. This was the most time consuming part of the entire process, and was what most people usually got stuck on. Even though the staff used the kiosks more fluently, their advantage was more of a result of knowing how to orient the items so the scanner picks it up quickly. I think in order to make it a pain-free process for most, the scanning process would need to be redesigned.

Posted by ben chao at 02:52 PM | Permalink

I did my observation assignment on a Saturday when I was running around town to get errands done. Since I was in public space most of the time, a lot of the interaction I observed only involved one person with his/her personal digital equipment - such as cell phone, blackberry, ipod, etc. One my subway ride from Lincoln Center to Union Square, I counted interactions with 17 cell phones, 7 portable music players, and 1 blackberry. Out of all the activities, the blackberry took the longest time of engagement, as the user was actively reading and typing the entire time.

Cell phone use was particularly interesting because people could do many different things with it. I saw several people just pulling out their phone and glancing at it, presumably to check the time or to see if they had any missed calls. A couple of people seemed to be playing games on their phones during the subway ride, which required enormous attention and as well as usage of both hands. The majority of the people that where SMS'ing also used both hands, but those that were making phone calls where able to operate their phone with just one.

Most of the users seemed extremely familiar and comfortable with their personal equipment, as they were all able to operate them with ease. However, this was not the case devices that were intended for the general public. At the Astor Place station, I saw four people gathering around the MTA vending machine, trying to figure out how to purchase subway tickets. Even though only one person was operating the machine, the others were all standing around him and giving him instructions.

Another public device I observed was the u-scan kiosks in supermarkets - which allowed customers to scan, bag, and pay for merchandise on their own. Even though most people seemed familiar with the process, there were those did not know how to operate the machine. Those that have used it before were able to get on their way rather quickly, in no more than 30 seconds. For others it was a long and arduous task, requiring long periods of fumbling with the items to find the bar code, figuring out when/where to bag them. It took them much longer time to complete the transaction - by about 1~2 minutes.

When using personal devices, the goal was mostly to communicate with others (in the case of cell phones, blackberry) or to get rid of boredom (cell phone games, ipod). Most public devices involved some sort of monetary transactions, such as paying for merchandises or a subway ride.

Posted by ben chao at 08:41 AM | Permalink

The hardest part of this lab was getting everything setup. I ordered my board from sparkfun, and received the NG version as opposed to the base version that most folks have. This did not work well with the school laptops - the COM would never register!! Where as the base board seemed to work without any additional software, the NG boards requried installation of these drivers from FTID. However, since nobody knew the admin login for the lab laptops, there was no way for me to install them. Luckily some folks in the lab also had the NG board, so we were able to work it out together.

I was able to install arduino (and the drivers) on my home computer without much trouble. Here it is in action!

switch off...

switch on!!

After struggling with school's computers for this lab, im seriously thinking about getting a laptop - pc or mac?

Posted by ben chao at 10:18 PM | Permalink

This was a rather painful experience at first. I started out by examining the index and css file. When I couldn't find some of the classes that were used, I suspected that Movable Type has a lot of hidden classes that we can't see (which I later confirmed by googling). A friend taught me some more advanced syntax for css which helped me understand a lot of the original css file. After examining the sources for a few sites and looking up some references, I was able to understand the jist of things. The hardest thing left was determining what to do.....

The main change to the website was moving the categories link right below the banner. This gives the reader more freedom to navigate around the website, since this can be added for all the different archives (date, categories, entry). It also provided a common place where the user can link to different topics, which could only be done by returning to the main site in the previous design. For the colors I choose earthlier tones since it's easiest on my eyes after a hard day of work....

Warning - MT's web-based editor seems to load everything from a database, so ssh'ing into your itp account and then updating the html and css files with emacs/vi won't actually change a thing. If you want to use an outside editor you have to follow the instructions here. I realized this after a rather painful one hour struggle where I had to rebuild the site numerous times.

Lesson of the week - read the manual!!

Posted by ben chao at 12:31 AM | Permalink

I know everyone is freaking out about this Peanut Butter Jelly time business, but I'm strictly a cheerios kind of dude.

Posted by ben chao at 10:15 PM | Permalink

The Angler

First came the nibble, then the bite. He pulled, tugged, and reeled in his prize after a prolonged struggle. At first hopeful, but then left with disappointment, he let it back to the ocean. It wasn't the One. The One that once tugged away his rod and twice busted his reel. He casted again, waiting.

Posted by ben chao at 01:04 AM | Permalink

1) Humans are creatures of habit. When they are used to one form of communication, they usually stick to it. It shouldn't come as a surprise that teenagers now-a-days are at the forefront of using the web to gather information. But you also have to keep in mind that there are kids out there that are complete newbies to these forms of communication, and may not be comfortable posting/finding info on the internet. If schools never teach these kids about what is available to them, they would be more and more segregated from the masses that do. Teaching them how to use such forms of communication is just as important as teaching them how to utilize it safely and responsibly.

2) The fact that institutions that receive federal funding are prohibited from using existing web infrastructures is extremely dumbfounding. These are sites people are accustomed to, and I think to encourage students to join, you need to stick to what they have used before. Creating a brand new portal for students is extremely costly, both for the government and the institutions, and does not guarantee success. Instead of recreating a model that already works they should work with what is available. If students are inclined to join existing public spaces, then the government should work with these companies to make them more secure, not excluding them from the process.

3) I think making technology available to everybody will be the next challenge for schools. Again, we don't want people to lose out on the opportunity to benefit from these mediums. Providing affordable access to such technologies will not only level the playing field for those less fortunate, but also provide students with more confidence in dealing with the web, which is an integral part of doing business these days. That is why projects such as creating the $100 laptop is so important.

4) Technology should be used to supplant existing teaching methods instead of replacing them. How successful a person is in the world really comes down to how well they deal with people. Being able to communicate over the web will take you far, but having person-to-person interaction is still what drives most relationships. I took an all on-line course during college - the subject was easy - but I did terrible, because there was nothing in it for me except filling my credit requirement. I knew nothing about my teacher, nothing about my classmates. Some people can work that way, but for me the inter-personal relationship is what ultimately makes things work.

Posted by ben chao at 07:54 PM | Permalink

First lab went well. I was able to finish it within an hour on a Sunday afternoon. Did not bring my camera so this will be an all-text entry....

Reminder - if the multimeter doesn't show 0.000 after being turned on, you should probably replace the battery.

First thing I learned this lab - LED's have polarity, so if it doesn't light up on first try, you should try switching them around. If you have a bunch of LED's in series the same board, its worth testing them one by one first to figure out the polarity - that way you don't have a gazillion LED's all in your circuit and no way of knowing which one(s) is put in wrong.

2nd lesson - when measuring amperage (current), the multimeter must be in series with the circuit you are measuring. If you put it in parallel, all the current actually goes through the multimeter instead of circuit. My first time measuring amperage I tried it like how you would measure voltage and my LED did not light up, but the multimeter still showed current going through.

Besides that, there wasn't much mystery to this lab. Just remember a few simples rules -

V = I x R
Voltage is the same across LED's in series.
Current is the same across LED's in parallel.

That's it for today!

Posted by ben chao at 06:04 PM | Permalink

This is actually the hardest assignment I've had through the first week of class. Being an engineer for the past 10 years, I've been trained to think about how to go from point A to point B, think about efficiency, think if things are plausible and how to get them done. So when I'm asked to read about something and then just comment about it, I was actually stuck. Engineers usually don't get the freedom to choose their own topic. It was both liberating and daunting. After being stuck on the assignment for a day, I just thought, what the heck, just write about whatever popped into my binary mind. After all, that is my reaction.

Why doesn't Movable Type have spell checking? I had to type everything up in word first then copy and paste it back.

I wrote individual points instead of one long piece because this is how information is organized in my head. The last time I've thought about transitioning from point to point was freshmen year in colllege for my writing class. I'm not good at it so I won't try - at least not today. No need for more stress.

Posted by ben chao at 12:08 AM | Permalink

what more can one ask for ...

Posted by ben chao at 10:59 PM | Permalink

hello world!

Posted by ben chao at 02:22 AM | Permalink