Lab 4: Sensing: Force sensors and Photo-cells

Yuetian Wang. Professor Kimiko Ryokai. Tangible User Interfaces, Fall 2021

Part 1 & Part 2

These two parts allowed me to learn how to use Photocells and FSRs to change the flow to adjust the blinking and brightness of the LEDs

Code

/*
Analog Input
Demonstrates analog input by reading an analog sensor on analog pin 0 and
turning on and off a light emitting diode(LED) connected to digital pin 13.
The amount of time the LED will be on and off depends on the value obtained
by analogRead().
The circuit:
- potentiometer
center pin of the potentiometer to the analog input 0
one side pin (either one) to ground
the other side pin to +5V
- LED
anode (long leg) attached to digital output 13 through 220 ohm resistor
cathode (short leg) attached to ground
- Note: because most Arduinos have a built-in LED attached to pin 13 on the
board, the LED is optional.
created by David Cuartielles
modified 30 Aug 2011
By Tom Igoe
This example code is in the public domain.
https://www.arduino.cc/en/Tutorial/BuiltInExamples/AnalogInput
*/
int analogInPin = A0; // select the input pin for the potentiometer
int redledPin = 9;
int blueledPin = 10;
int greenledPin = 11;
void setup() {
// declare the ledPin as an OUTPUT:
pinMode(redledPin, OUTPUT);
pinMode(blueledPin, OUTPUT);
pinMode(greenledPin, OUTPUT);
}
void loop() {
// read the value from the analog input pin:
const int sensorValue = analogRead(analogInPin);
// turn the redledPin on
digitalWrite(redledPin, HIGH);
digitalWrite(blueledPin, HIGH);
digitalWrite(greenledPin, HIGH);
// stop the program for <sensorValue> milliseconds:
delay(sensorValue);
// turn the ledPin off:
digitalWrite(redledPin, LOW);
digitalWrite(blueledPin, LOW);
digitalWrite(greenledPin, LOW);
// stop the program for for <sensorValue> milliseconds:
delay(sensorValue);
}

Homework

Description

For the homework, I I tried to modify the code provided on bcourse to get a circle that can change color and size according to the value of FSR. My code is very simple. But for me who just started to learn to code, it’s not easy.

Code

/*
arduino_input

Demonstrates the reading of digital and analog pins of an Arduino board
running the StandardFirmata firmware.

To use:
* Using the Arduino software, upload the StandardFirmata example (located
in Examples > Firmata > StandardFirmata) to your Arduino board.
* Run this sketch and look at the list of serial ports printed in the
message area below. Note the index of the port corresponding to your
Arduino board (the numbering starts at 0). (Unless your Arduino board
happens to be at index 0 in the list, the sketch probably won’t work.
Stop it and proceed with the instructions.)
* Modify the “arduino = new Arduino(…)” line below, changing the number
in Arduino.list()[0] to the number corresponding to the serial port of
your Arduino board. Alternatively, you can replace Arduino.list()[0]
with the name of the serial port, in double quotes, e.g. “COM5” on Windows
or “/dev/tty.usbmodem621” on Mac.
* Run this sketch. The squares show the values of the digital inputs (HIGH
pins are filled, LOW pins are not). The circles show the values of the
analog inputs (the bigger the circle, the higher the reading on the
corresponding analog input pin). The pins are laid out as if the Arduino
were held with the logo upright (i.e. pin 13 is at the upper left). Note
that the readings from unconnected pins will fluctuate randomly.

For more information, see: http://playground.arduino.cc/Interfacing/Processing
*/

import processing.serial.*;

import cc.arduino.*;

Arduino arduino;

// Change this pin number to match where you actually have an LED in your
// circuit
int ledPin = 9;

// Change this pin number to match where you actually have a pot in your
// circuit. Note that pin 0 is the same as pin A0, pin 1 is same as A1, etc.
int potPin = 0;

void setup() {
size(500, 500);

// Prints out the available serial ports.
println(Arduino.list());

// Modify this line, by changing the “0” to the index of the serial
// port corresponding to your Arduino board (as it appears in the list
// printed by the line above).
arduino = new Arduino(this, Arduino.list()[0], 57600);

// Alternatively, use the name of the serial port corresponding to your
// Arduino (in double-quotes), as in the following line.
//arduino = new Arduino(this, “/dev/tty.usbmodem1411”, 57600);

arduino.pinMode(ledPin, Arduino.OUTPUT);
}

void draw() {
// We can control the Arduino from Processing
int potVal = arduino.analogRead(potPin);
int ledBrightness = int(map(potVal, 0, 1023, 0, 255));
arduino.analogWrite(ledPin, ledBrightness);

// We can also draw to the Processing window
// setting the background to black (red = 0, green = 0, blue = 0)
background(0,0,0);
// pick up the white paintbrush (red = 255, green = 255, blue = 255)
// the next shape we draw will have white color fill
color a = color(255, 0, 0);
color b = color(0, 255, 0);
color c = lerpColor(a, b, map(potVal*0.3, 0, width, 0, 1));
fill(c);
ellipse(width/2, height/2, potVal/3, potVal/3);
}

Components Used

1-Arduino

1-Breadborad

3-LEDs

3–220 ohm resistors

1-FSR

1–10k ohm resistors

Some Wires

Video