Phototransistor 

What does the sensor do?

phototransistors detect ambient light. Inside the cylinder is a little chip that generates current from long lead to the short lead when a light passes by. It also uses “less toxic ingredients” to produce than regular photo sensors, making transistors more envrionmental friendly (adafruit). Similar to a photoresister, both products produce “less current flow when darkened than when lighted” (Sensor Workshop at ITP).

How does the sensor work?

As a light-sensitive transistor, the more light passing the chip inside means the more current that will be induced. To use, connect the longer leg to power bus, and connect the shorter bus to ground via 1k-10k resistor. As an analog sensor, make sure that the shorter leg is also connected to an Analog input friendly pin on the Arduino. “When it’s dark, there’s almost no current flowing through the sensor or resistor and the analog voltage is near ground. When there’s light near the sensor, the current through the resistor will increase, raising the voltage” (adafruit).  The voltage range can be adjusted through changing the resistor. 

trying out the sensor

(input (A6) was the phototransistor; input1 (A7) was FSR that I was also playing around with — the left values on the serial monitor is the readings from the phototransistor)

I enjoyed using the sensor because it was pretty similar a photoresistor, which I was pretty familiar with. However, I did notice that phototransistors did not react sensitively to regular room light (whereas photoresistors do react to regular room light). Rather, it sensed flash light from my phone much better, and the input value increased depending on how strong the light was affecting the transistor. I thought it was interesting to see that the transistor almost seem to detect the distance of the light source (the input value increased as my phone’s flash light got closer to the transistor). 

To clearly see the difference between a phototransistor versus a photoresistor, I tried both sensors in the same environment. Below is the result: 

https://drive.google.com/file/d/1gIx-_bNpu0EwA2H6ZHHyVdx5KaMd5_rb/view?usp=sharing

In the video, the first number on the serial monitor is the phototransistor. Then, the second number is the photoresistor, while the third number is a FSR value that can be disregarded. As shown in the video, while the photoresistor is more sensitive room light, when the source of light changes to a lamp, phototransistor can be intepreted to be more ‘accurate’ in terms of how powerful the light is (depending on the distance from the light source). 

What worked and what didn’t work? Any questions?  

I’m still having a hard time figuring out what kind of specific situation (that is also practical in real life) would require a phototransistor than a photoresistor. 

Circut/Example Code

Phototransistor: 

• connected to A6 (shorter leg) + 10k resistor from A6 to ground bus 
• longer leg to power bus 

Photoresistor: 

• connected to A3 (shorter leg) + 10k resistor from A3 to gorund bus 
• longer leg to power bus

potential applications of the sensor

Photoransistors may be better suited for scenarios that might require a specific light to be detected . On the other hand, photoresistors may be better suited for sensing the overall brightness of a spacial area. 

Because the phototransistor seems to be more accurate in the sense that it can detect the distance of the light source, I thought the sensor might be applicable to helping humans maintain a safe distance from a light source. For example, the sensor could be implemented to glasses that lets the wearer know when the user has a monitor (laptop, tv, phone, etc.) too close to his/her face. 

Another possible application of transistors might be found in parking spaces. Because cars have their headlights on when parking, phototransistors may be implemented on walls to prevent the car from backing up too far (by detecting the light intensity from the headlights which would technically be measured as ‘distance’). However, I realize that distance sensor would be much more reasonable. 

Possible Project ideas

light tag game with a spin?

• everyone is in a dark room 
•  everyone is wearing a LED suit, but only the designated tagger (starts with a single tagger) has the LED suit turned on (like the picture below). 

• participants will have the phototransistor attached to their shoulders
• timer will be set to 5 minutes
• tagger will run around and tag people on their soulders 
  • phototransistor will detect the light when tagged — this will trigger the LED suit to turn on 
• Game ends when everyone has their LED suit on (tagger wins) OR when the timer goes off before all LED suits are on (remaining people win) 

Building a (small and unreasonable) Project

alarm clock? 

Using p5, phototransistor, and FSR, I created an alarm clock. 

How it works:

• when the environment is dark, ‘resting’ mode is the default; there is no alarm
  • resting mode = dark background, yellow moon, no alarm, “resting…” text
• when the phototransistor senses light (anything above 100), ‘morning’ mode turns on – I made this value small because phototransistors are not too sensitive when detecting room ambient light, and I thought the same thing would apply for regular sunlight coming into the room when it’s morning 
  • morning mode = bright background, orange sun, alarm sound goes off
• the user has to to press the FSR (over 400 value — it’s not that hard) in order to stop the alarm sound
  • the entire loop will stop (including the movement of the sun), and ‘good morning!’ message will pop up
  • when playing videos, make sure that the sound is on!

computer view: 

https://drive.google.com/file/d/1XRFL2nGojXwABttPIq70-C6KNfNDYAmS/view?usp=sharing

p5 sketch: 

https://editor.p5js.org/jiwonyu/sketches/EF_z3_dEI

websites referenced: 

https://itp.nyu.edu/archive/physcomp-spring2014/sensors/Reports/PhototransistorsPhotocells.html

https://cdn-shop.adafruit.com/product-files/2831/HW5P-1_2015__1_.pdf

https://www.adafruit.com/product/2831

I personally really resonated with the article — it made me realize that what I thought was ‘desired’ by our society has been constructed by the ‘normal’ people who fall under the ‘normal’ section of the bell curve. 

When we make ‘assistive’ tools for the ‘disabled’ we are putting such a distinctive gap between the ‘normals’ and the ‘disabled’ : ‘us’ versus ‘them.’ Therefore, when the ‘abled’ make assistive tools for the other party, the tools are made so that the ‘disabled’ can look ‘abled.’ The tools are made (aesthetically) to look discreate so that one can hide their ‘disability.’ However, reading this article made me realize that, although achieving this ‘normal’ look may be desired by some, this desire has been largely shaped by the ‘normal’ people, who believe that appearing ‘normal’ is what the ‘disabled’ long and desire. Below is a quote that I found relatable to this topic: 

“Plenty of well-meaning designers set out to re-design an object so that its wearer won’t “appear disabled,” with the presumption that a preconception of “normal” is always desirable.”

Rather than trying to make ‘disabled’ look ‘normal,’ what we need to focus on is to rerange and redefine ‘normalcy’ to include a wider population: disabled does is not automatically correlated to abnormal. Then, with the newly defined normalcy, we can aim to construct technological tools that appeal to all — aesthetically and functionally. 

“Once freed from thinking in terms of creating tools for disability, designers can  create personal objects that disrupt our notions of dependence and autonomy.”

Lastly, Jennifer Crupi’s gestural jewelry stood out to me because it throws out the notion that tools should look unnoticable. Instead, Crupi makes a powerful statement by choosing to deliberately enhance the mechanical look of the tools via her metal work. As an effect, she is able to display “the authoritative position of steepled fingers.” Crupi’s devices help the user to rehearse “one’s self-presentation” instead of hiding it like the conventional assistive machines, which is a method that I want to incorporate in my future works. 

 

https://www.notion.so/dav1dyang/Chicken-Game-e7d2633dbb8248449c1ddf2a4593b9a1

 

https://docs.google.com/document/d/1rqo-vNFCd8wWwh-Y5I0iXba6ybdqn-hQdfGxpfNIuz4/edit

 

for the tone lab, my codes seemed to have a problem; the “include pitches.h” on the very top of my code was highlighted red every time I tried to upload the code; the screen at the bottom was stuck at “uploading…” and would not proceed. Below is the copy: 

I know the speaker is working, since I got it to make noise with a potentiometer. However, my potentiometer was super unstable and the frequency kept changing by itself. Below is the video demonstrating that: 

IMG_6916

Although it was unstable, when I rotated the screw, the numbers on the serial monitor would show the correct increase/or decrease in number. This should’ve made the frequency change when I rotated the potentiometer, but maybe my circuit was wrong — the notes did not change.

I will update things as progress gets made

I tried the ‘blink’ example to see if my port was working, but it also did not work; the screen is still stuck and uploading stage. I will book an office hour to figure this problem out. 

What is Tangible Interaction good for?

Tangible interaction is suitable for making the users feel like they are part of the art because they are physically making a change in the environment — which gives the user the sense of power and authority. This can provide comfort and ease to the user, for they feel like they are in control. Therefore, tangible interaction would be suitable for creating technology/art that would be beneficial for someone to be in control (similar to like a steering wheel in the car; a person would likely be want to be in control). It would also be good for making the pace of the interaction more individualized to each individual.

What is Intangible Interaction good for? What are the differences between the two?

Intangible Interaction is good for allowing the user to enter a different realm — when technology is not physically controlled by the user, it can feel like the technology/art is making changes on its own, manipulating people to
In the reading, it was clear that intangible interactions were at an advantage during covid-19 because of health concerns and social distancing concerns. Therefore, it seems that intangible interactions may be better for hygienic activities. Furthermore, it was interesting to see that this restriction of space and proximity and the concerns for covid-19 did trigger an expansion of creativity. Because the artists were limited, they had to think outside the box to achieve something within a small scope.

An example of a difference that I can think of is manual scooters vs. automatic scooters. I feel much safer and in control when I am on a manual scooter, whereas in an automatic scooter, I am in a constant state of anxiety that I might be hit by a bus because I would not be able to stop the scooter.

Can you think of any good (or bad) examples/uses of tangible/intangible interactions in everyday life, product design, art project, exhibition design, etc?

tangible: elevator buttons, car steering wheel, unlocking doors with card, daily screener, charging technology via charging port

intangible: tesla auto, traffic light, face ID, the bathroom automatic sensor

For this week’s assignment, I wanted to incorporate the counting ability of the Arduino and the LED. 

The concept was that when the button is pressed a certain amount of times, the monitor would display annoyance: “bruh stop pressing me” and ” is this fun?” are just a few of the phrases the monitor will give back to the user. 

Then, after a certain number of times the button has been pushed, red LED will light up, indicating that Arduino is r e a l l y mad at the user. 

Although I got the computer to say phrases in the monitor depending on the amount of times the button has been pushed, when I tried to run the code for turning on the Red LED, the USB ports on my laptop suddenly started to not work. After multiple attempts of unplugging and plugging for an hour, I decided to try again tomorrow morning and hope that my code for the LED is correct. This paragraph is in Comic Sans because my life is a joke at this point 

For future developments, I want to incorporate using arrays and random function so that the computer can generate random statements from the possible sayings in the array.  I would also like to have a green LED that would be on until the user has pressed the button enough. When the user reaches the limit, the green LED would go off, and the red LED would turn on. 

 

also, I’m not sure why the photo qualities are so bad — even the screen screen capture ones. Here is the code that I did: 

int lastButtonState = LOW; // state of the button last time you checked
int buttonPresses = 0;

void setup() {
// initialize serial communication:
Serial.begin(9600);
// make pin 2 an input:
pinMode(2, INPUT);
pinMode (3, OUTPUT);
}

void loop() {
// read the pushbutton:
int buttonState = digitalRead(2);
int led = digitalRead (3);

// if it’s changed and it’s high, toggle the mouse state:
if (buttonState != lastButtonState) {
if (buttonState == HIGH && buttonPresses <30) {
buttonPresses ++;
Serial.println(“Button was just pressed.”);
Serial.print (buttonPresses);
Serial.println (“times.”);
}
if (buttonPresses > 10 && buttonPresses <30) {
Serial.println (“bruh stop pressing me”);
} if (buttonPresses >15 && buttonPresses <30) {
Serial.println (“is this fun?” );
} if (buttonPresses > 20 && buttonPresses <30) {
Serial.println (“go work on your homework” );
} if (buttonPresses == 25&& buttonPresses <30) {
digitalWrite (3, HIGH);
delay (100);
digitalWrite (3,LOW);
delay (100);
digitalWrite (3, HIGH);
} if (buttonPresses == 30) {
Serial.println (“goodbye”);
}
else {
digitalWrite (3, LOW);
}
}
// save button state for next comparison:
lastButtonState = buttonState;
}

update: it’s the morning and the laptop still can’t read my usb port 🙁 

second update: after resetting my Arduino by pressing the reset button twice (thank you Yeseul), my computer was able to read the port again. 

However, my LED was not working, and with my intuition I got the led pins out and saw that the long leg was connected to ground. After changing it, it worked yay! Here is a video: 

IMG_6862

 

The Korean Grandma video showed a clear example of who the technologies are geared towards: younger generations with some proficiency in both interfacing technology and English. There is also a lack of instructions. As Korean Grandma complained at the end of the video, there is no human helper aiding anyone who may struggle with technology next to the machine. This shows that there is a huge assumption about the consumers: the companies assume that the person ordering fast food would be of a younger age who has experience with digital technology like laptops, TVs, or phones.  

• • • The words “take out” and “French fries” were not directly translated to Korean — Korean Grandma mentioned that “take out” should be written as “포장,” which is a direct translation from the English word. However, on the screen that she was using, both “take out” and “French fries” are written as to how they would sound in English but only spelled with Korean letters. 
      • • take out = 테이크 아웃
        • French fries = 후렌치 후라이

Furthermore, I realized that visual components, primarily pictures, play a critical role in expanding the audience for technology. This was clear when Korean Grandma tried to distinguish different food options from each other purely based on pictures presented, and even then the system failed her, and she ended up getting coffee instead of coke. Similarly, font size plays a huge role too. The reason why Korean Grandma opted to use pictures as references were not that she is not capable of reading. Rather, it was because the font size was too small for her to see, making the accessibility of the machine much lower to those with bad eyesight.

• • • The font size struggle was clear when Korean Grandma accidentally ordered coffee instead of coke. I believe that this is because “coffee” and “coke” in Korean start with the same letter (and they both have two syllables), making them hard to distinguish. 
      • • coke = 콜라 
        • coffee = 커피
        • notice how they both start with “ㅋ”

Lastly, it was intriguing to see that Korean Grandma made an instant connection between how the fast-food chain operated to how banks operated. Could this portray how every domain of our lives would be transformed to interface technology in the future? Will everything be unified into one method?