hjc309’s blog

Final Project (prototyping)

December 18, 2007 on 3:39 am | In Physical Computing | No Comments

Seung Jun and I are partners for the final project. We are both Asian and we decided to come feature some Asian custom in our project. We are going to feature a traditional Korean tea ceremony.
We will note that this ceremony is a casual affair. There are few rituals. Rather the point is to relax, converse freely and enjoy beverages and snacks.
Our project will include a table with four cups at each corner. An LCD will be installed in the middle of the tea table. When people remove a cup or place it back on the table, some fact about the tea ceremony will appear in the LCD.
We will use FSR sensors for the cups. However, this raises the problem of accurately setting up the codes to interact with the cups. There might be confusion if the cup is passed between people, rather than being removed once and then placed back by the same person.

Get creative

December 18, 2007 on 3:22 am | In Physical Computing | No Comments

I made a cake with three LED candles. A microphone was placed in the cake to activate the light. I tried to make the LEDs fade out when someone tried to blow out a candle. This project was for my 8-year-old nephew. Unfortunately, I didn’t have time to make eight candles, but I hope he will still like it.

click to watch

Week7-DC Motor Control

November 29, 2007 on 1:28 am | In Physical Computing | No Comments

This was definitely one of the harder labs. I found it difficult to interpret the schematic. I went slowly, deciphering each step. I thought I had done everything right, but nothing happened. I went over my board again, but still no result.
The LED flickered at first, then blinked and did nothing. I redid my board, reviewed the schematic and read through the lab. Nothing. I reloaded my code many times. The LED flickered again then went out.
Finally, I asked for some help. They went over my board and checked my pins. Still nothing worked.

DC Motor Control

Midterm week

November 29, 2007 on 1:15 am | In Physical Computing | No Comments

Midterm week1-Observation

I observed a man playing the bongos in a city park. Bongos are a pair of drums each about the size of a small bucket. One is slightly larger than the other. They are made of wood with a “skin,” which can be animal or synthetic, stretched tightly across the top. Metal tuners stretch the skin to create a higher or lower pitch. The pitch is also influenced by the size of the drum. Thus, the larger drum provides a lower pitch than the smaller drum.
The goal of this activity is to provide rhythmic music, or percussion. In this case, the bongos were being played solo. They may also accompany other drums or musical instruments. In some cases, perhaps, these bongos would also be accompanied by dancing. In the case observed, the bongos were being played for the enjoyment of the player. The man was sitting on a bench with the bongos on his lap. His hands struck the tops of the bongos. There appeared to be some variation between what parts of his hands struck the bongos. In some cases, the man’s palms appeared to be striking the drums. In other cases, the man’s fingers and thumb appeared to be doing the striking. The location on the drum also appeared to change according to the sounds the man desired to achieve. It appeared that a higher pitch sound came from the edges of the bongo. This would make sense. The tension would be higher in these areas because the skin was wrapped tightly around the edge of the bucket.
The man’s head, shoulders and torso swayed as he moved to the rhythm of his playing. His arms were relatively fixed from the shoulder to the elbow. His forearms provided most of the movement. They moved up and down to beat the drums. They also moved along a horizontal plane in a circular motion, as if he was also rubbing the drums. His lower body remained fixed. His legs moved up and down to the rhythm of his playing.
His attention was focused on the contact being made between his hands and the top of the drums. One set of hands and arms moved independent of the other set. Secondary focus of attention was in the motion of his arms and the tapping of his legs, although this focus could have been unconscious to the player. The most engaging aspect of the playing was the rapid striking of the bongos with the hands. This created a sharp, short sound. There was very little reverberation, or echo. The sound lasted just as long as the hand hit the drum. There was little variation in sound or rhythm. This created a trance-like effect on the player and the listener, which could lead to boredom.
After viewing a recording of this man playing the bongos, the initial observation was confirmed. Different parts of his hands and fingers struck the bongo. Also, different parts of the bongo were struck. Observation confirmed that these variations were deliberately done to get a different sound from the bongo.

Midterm week2

We have decided to add sound effects as the drums are played and the images are displayed.
Our drum is made from paper and clear vinyl.
We also bought a toy drum as our prototype. Arduino programming was uploaded to Arduino board. We tested very bright LED lights as we hit the drum.
This test required us to reprogram the Arduino board so that the light stayed on longer. This was accomplished by using the delay function. This keeps the light on longer to display the image.
The image will be created by placing a cut-out pattern on the top of the drum.
We connected the Arduino board to the speaker and uploaded the sound effects.
We have failed so far in initiating the sound and light programming when we hit the drum. We have tried several methods, all unsuccessfully. We will ask Greg and others for ideas.

Midterm week3

We decided a good idea for the drum project would be to shine an image on the ceiling every time the drum was struck. We discussed what power of light we needed to accomplish this task. If we were going to use LED or a higher-watt bulb, we decided we would need a powerful light. In the future lab, we realized we needed to use a relay or a transistor to active the higher watt bulb.
Based on the advice of Tom Igoe, we used a focus lens for our light display. He also recommended a slight delay between the hitting of the drum and the shining of the image. He also recommended that he use a light projector for shining these images.
We began work on this idea with the Arduino and Processsing programming. We also asked other students for their ideas. One idea came from Sean. He suggested an interesting interface for the images. We sprayed the drum and adorned with LED lights.

This project required a variety of skills that relate to my own interests. By observing an individual play a drum, we were inspired to make this process more interactive and more high-tech by adding light and sound effects. This required very bright lights to get the image from the drum to the ceiling or a screen. We used powerful LEDs and tried it in darkened rooms. We also added special sound effects with photocell sensors. We placed a microphone in the drum to active animation and the light and sound effects.

click to watch

Week5-Serial

October 10, 2007 on 4:13 pm | In Physical Computing | No Comments

This lab requires me to work with two potentiometers, a push-button switch and 10kohm resistors. I entered some of the code examples provided. I entered the code for raw pot value, corresponding binary, decimal, hexadecimal and octal value.It took me quite some time to run the Terminal program.
I took a program into Processing to manipulate data with the analog sensors. This moved a ball around. I ran the command to give Processing access to my serial power and had great results.

Serial output and Talking to Processing
click to watch

Week4-Servo/Analog out

October 3, 2007 on 3:29 pm | In Physical Computing | No Comments

Our instructions asked us to wire the servo motors that come in our kits to the potentiometers. The analog output on the servo does a nice job of reflecting the action taken on the potentiometer.

Analog output - RC Servomotor, Potentiometer

Week3-Analog in

September 24, 2007 on 2:40 am | In Physical Computing | No Comments

This was my first introduction to analog input. I started with a potentiometer. Connecting it was simple. So was using the code for input and output.

Analog In

click to watch

Week2-Digital Input and Output

September 24, 2007 on 2:36 am | In Physical Computing | No Comments

This week I received an introduction to the Arduino microcontroller and software. We used the software and existing code to digitally power and control the path of energy across electrical components. This replaced our previous use of a power adapter to charge the circuit.
I assembled a circuit connecting the power and ground bus to the those on the Arduino. I added a couple LEDs and some two 220ohm resistors. Then I added a switch before linking up to the Arduino’s digital pints 3 and 4. This turned on the LEDs, one each with each press of the switch.

Digital Input and Output

click to watch

Week2-Observation

September 12, 2007 on 3:42 pm | In Physical Computing | No Comments

click to watch

I observed the interaction between pedestrians, vehicles, traffic lights and pedestrian signals at a mid-town intersection. The time of day was 3 p.m., between lunch hour and rush hour. I chose this time because I figured traffic would be lighter during this time. I did not want to pick a time when traffic was at its peak, since I figured vehicle behavior and pedestrian behavior would follow a set pattern. For example, the large number of vehicles and pedestrians in the streets and sidewalks at that time would result in vehicles and pedestrians generally observing the right of way of each other according to the traffic and pedestrian signals.
The interaction occurs as follows: Pedestrians approach the intersection on foot. They observe the traffic flow from both directions, they observe the pedestrian and/or traffic signal, and they either proceed across the intersection or wait. If they wait, they begin the interaction over again. The interaction is most difficult for the pedestrian when traffic is relatively light. This creates ambiguity in whether they should observe the pedestrian signal’s alert to refrain from crossing since they perceive no danger from oncoming traffic.
There are two sensory inputs during this time. Their is the visual input of the pedestrian and traffic signals, and there is the visual input of the vehicle flow. It usually takes only a few seconds for the pedestrian to input the information from these sources and make a decision as to whether to wait or cross. However, sometimes this process occurs more than once before a cross decision is made. For example, sometimes there are gaps between vehicles that potentially could allow the pedestrian to cross. But it’s possible the gap is not large enough. The pedestrian often waits for gap to open, then make another very quick decision about whether to cross.
Other pedestrians behaved differently. This more patient group made one decision based on one input: If the pedestrian signal allowed them to cross, then they would cross. They did not try to cross in violation of the signal. Many of these pedestrians also checked whether it was safe to cross even though the signal instructed them to cross. This proved to be a wise decision since in some cases vehicles would run the red light. These individuals seemed to suffer less anxiety than the impatient group that constantly evaluated whether it was safe to cross against the signal’s instructions. The impatient group rarely saved more than a few seconds than their patient counterparts. The few seconds that some of them were able to save came at the expense of having to run across the intersection. Their interaction with the signal appeared to create more stress. This is ironic given the fact that they probably would claim they were motivated to cross in violation of the signal in an effort to save time.
Another element of this interaction was the influence that pedestrians had on each other’s decision to cross. It appeared that an impatient pedestrian’s decision to cross in violation of the signal influenced patient pedestrians to join them. Evidence for this is based on the fact that patient pedestrians were making no effort to evaluate oncoming vehicles. They were simply waiting patiently for the signal to allow them to cross. But when an impatient pedestrian began to cross, they would also make a quick evaluation of oncoming traffic and follow the impatient pedestrian if it appeared safe to cross.
What is most interesting about this interaction is that there appears to be no significant benefit from crossing against the signal’s instructions. Only a few seconds were saved, and to take advantage of these required expending more energy on evaluating the safety of crossing and rushing across the intersection. It appears that these impatient pedestrians consider the pedestrian signal as a barrier to their progress, and thus they invest more energy in exerting their own self will than is beneficial to them.