Arduino Code:

int analogPin = 0;
int analogValue = 0;

void serialEvent(Serial myPort) {
// Get the byte
int inByte = myPort.read();
// Print it
//println(inByte);
// Set the drawing color
stroke(123,128,158);
// Draw the line
line(graphXPos,height,graphXPos,height-inByte);
// At the edge of the screen, go back to the beginning
if(graphXPos >= width) {
graphXPos = 0;
// Clear the screen
background(48,31,65);
}
else {
// Increment the horizontal position for the next reading
graphXPos++;
}
}


Arduino Code:

/*
Theremin

void loop() {
// get a sensor reading:
int sensorReading = analogRead(0);
// map the results from the sensor reading's range
// to the desired pitch range:
int pitch = map(sensorReading, 50, 800, 100, 1000);
// change the pitch:
noiseMaker.play(pitch);
}


In this lab, the diagram shows the analog input as two photocells wired in series. I’m not sure I understand the analog readings produced as a result of this. For example, when both photocells were fully exposed to light the reading was about 200. When the right photocell was covered, the value jumped to 600-800. If only the left photocell was covered, it lowered the reading to about 50. If both were covered, the value leveled out around the same 200 as when they were both fully exposed. I’m not sure I understand the circuit and why these variable resisters were producing these values.

- Press on-screen “Start” button to begin
- Follow on-screen instructions from this point forward
- Choose to refill or get new metrocard
- Choose fare type
- Choose payment method
- Insert payment method
- Select if receipt is desired
- Retrieve ticket and receipt

In the TYPICAL CONTEXT the user finds him- or herself in is one that causes ANXIETY. Usually the user-to-be can expect to be in a queue waiting to use the machine and get their metrocard. If they aren’t already experiencing anxiety (maybe running late and don’t have time to wait in line), once it is their turn anxiety really sets in. Anxiety results from the need to be quick to get a metrocard before those waiting behind you become impatient.

Observations:
*Note observations took place on a weekday during morning rush hour.

On average each user took approximately 1 minute to complete their transaction and receive their metrocard. The time of observation suggests that for the majority of people observed, this is not their first time using the machine and have become accustomed to its user interface.

After realizing the screen was a touchscreen, the user interface does a pretty good job of prompting the user for their next action. For those not sure what type of metrocard they want, this is the first point of hesitation in which a decision has to be made. Afterward when the user chooses a payment option, they quickly survey the machine to see where the machine accepts their credit card or cash. The many slots for credit cards, cash, receipts and tickets has a tendency to confuse. Finally, the metrocard and receipt (if desired) is dropped into the lower compartment for retrieval (which some users cannot find).

*Had I observed this public interactive technology on a weekend or at a tourist-heavy station, my findings most likely would’ve been more dramatic. I doubt it was the first time using the machine for anyone I observed on this particular morning. In short, I think everyone would experience more difficulty using this machine the very first time. The user learns from their first experience and knows what to expect next time.

Another interesting interface design choice was to use the touch screen for all user input, except typing the zip code associated with the user’s credit card. For this input, the user has to leave the touchscreen and use a keypad found elsewhere on the machine.

UPDATE: It’s been suggested that using the physical keypad for zipcode entry is most likely a security measure.

Homemade Soil Humidity Sensor

Sensor reading when dry

Sensor reading when wet

The alert system functions by illuminating the green LED while the plant is properly watered and switches the red LED on when the plant is in need of watering (or dry). Also, when the soil is dry and the plant is watered, the system will turn the red LED off and the green LED on.

A small improvement to this system would be to have the green LED dim proportionally as the soil becomes more and more dry, then the red LED would ultimately turn on when the soil is completely dry.

A couple long-term improvements would be to (1) devise an automated watering system or (2) have the plant twitter or sms the owner’s phone to remind him/her that it needs to be watered.

I successfully connected a DC power source using an AC-to-DC power adapter and a voltage regulator. Then I experimented with the multimeter to measure both amperage and volts through individual components and full circuits. As well as how voltage and amperage differs when components are in a series vs in parallel.

Language Learning Glasses

I’m simultaneously fascinated and frustrated with the rate at which a child can learn new languages. As we grow older, our ability to easily learn other languages dramatically decreases. Rosetta Stone has developed a system where you learn a foreign language based on word/picture associations. The idea is that when you see the spanish word “manzana” you immediately think of the object, not the english spelling “apple.”

These fantasized language learning glasses would couple a heads-up-display (HUD) with direction speakers to create an augmented reality. For example, as you walk through the grocery store, the glasses recognize objects, show the associated word in your language of choice on the HUD, and a voice pronounces it for you. It is Rosetta Stone 24×7.

void loop() {
potValue = analogRead(potPin); // read teh pot value
analogWrite(led, potValue/4); // PWM the LED with the pot value (divided by 4 to fit in a byte
Serial.println(potValue); // Print the pot value back to the debugger pane
delay(10);
}


PComp-Wk2-Lab from Steve Aquillano on Vimeo.

To begin I translated the circuit to the breadboard. Afterward I compiled and uploaded the program to the arduino microcontroller.

End result: When the switch is off, the red led is on. When the circuit is switched on, the red led turns off and the yellow led turns on.

Switch Off

Switch On

// declare variables:
int switchPin = 2; // digital input pin for a switch
int yellowLedPin = 3; // digital output pin for an LED
int redLedPin = 4; // digital output pin for an LED
int switchState = 0; // the state of the switch

void setup() {
pinMode(switchPin, INPUT); // set the switch pin to be an input
pinMode(yellowLedPin, OUTPUT); // set the yellow LED pin to be an output
pinMode(redLedPin, OUTPUT); // set the red LED pin to be an output
}

void loop() {
// read the switch input:
switchState = digitalRead(switchPin);

if (switchState == 1) {
// if the switch is closed:
digitalWrite(yellowLedPin, HIGH); // turn on the yellow LED
digitalWrite(redLedPin, LOW); // turn off the red LED
}
else {
// if the switch is open:
digitalWrite(yellowLedPin, LOW); // turn off the yellow LED
digitalWrite(redLedPin, HIGH); // turn on the red LED
}
}

PComp-Wk1-Video from Steve Aquillano on Vimeo.