Computational Crafting with Arduino

Christopher Michaud

Marist School

ECEP Programs, Georgia Tech

Introduction

• What do you want to learn and do today?

• Goals with Arduino / Computational Crafting

Purpose

• Encourage and develop a mindset of iterative interaction between materials and electricity

• Identify difference between Engineering and Art.

STEAM: Science Technology Engineering Arts Mathematics• What is “Engineering”?

• What is “Art”?

Engineering

• Given a problem to solve:

• Using a design process to Analyze, Design, Implement, Test and Deliver a system that solves that specific problem.• Architecture

• Hardware

• Software

• Process

Arts

• Encode non-verbal Human Expression in a dynamic system that humans can reflect on, change, and share.

• Arts are interactive and designed for encoding and sharing non-verbal expressive human thought.• Bennett Reimer: A Philosophy of Music Education

Research and Development

• Lies in that space between Arts and Engineering

• Most education/activities we call “Engineering” for students are actually Research and Development or Arts type activities.• “Explore”• “Create”• “Develop”

• This causes tension between “Engineers” and Artists. (and sometimes within us)

• Example: “Help me fix this problem” and then “Expert” needs to “Research and Develop” before they can engineer a solution . . . (Tech Support )

Where does this apply in Teaching? (and STEAM teaching)• Define the Goal of the Activity!

• Are we . . .• Tinkering with software or tool (Learning a specific set

of skills or software) (Equipping)

• Solving a Specific Problem (Often designed by teacher or curriculum)

• Engaging in Artistic Expressing (or Research and Development)

• Engineering a solution to a problem we defined

• Implementing the Solution!

Example: Music

• Tinkering: • Practicing Scales / Etudes

• Learning Fingerings

• “Noodling”

• Solving Problem: Learning a piece of music somebody else has written.

• Research and Development: Improvising

• Engineering: Composing

• Implementation: Performing for audience

Example: Computer Science

• Tinkering: Playing with Scratch, learning syntax of programming language

• Solving a Problem: Given a problem, develop an algorithm to return the proper values

• Research and Development: Experimenting with programming systems

• Engineering: Working with a customer to define problem and design software system

• Implementation: Writing the code to solve the problem you defined and giving to customer

Student, Artist, or Engineer?

• Each Activity / Lesson / Learning Experience needs to be defined in the context of purpose.

• Keep STEAM relevant in education long after the acronym fades from interest.

Examples of Computational Crafting

Electricity: Just enough knowledge to be dangerous

Elements of Electrical Circuits

+

-

Power Source (Battery, Wall Socket)• Have a positive and negative side (Battery

Example)

• Difference in Charge or Potential Energy

• Measured in • “Volts” (V) or

• “Electro-motive Force” “E”

Resistor

• Light Bulb, Motor, other equipment that resists flow of electrons

• Control the flow of Electrons in a Circuit

• Fixed or Variable

• Measured in “Ohms” or “R”

Current or Amps

• The amount of electrons flowing at a given point in time

• Measured as “I”. Also called “Current”

• One Amp = 1 Coulomb per second.

• A Coulomb is equal to 6.2450962×10^18 electrons

Power

• Unit of Work

• Measured in Watts (W)(P) or Horsepower)

• 1000 watts (1 Kilowatt) = 1.34102209 Horsepower

Algebraic Relationships between Volts(V), Resistance(R), Amps (I), and Watts (P)

A 36 Volt Battery supplies current to a 3 Ohm Resistor. -How many Amps flow through this Circuit?

-In 1 second – how many electrons flow past this point in the circuit?

-What is the Power in Watts produced by this Circuit?

Pin 9 supplies 5 Volts to the LED and the 330 Ohm resistor.

-What is the measurement for Amps in this circuit. (Give answer in milliAmps)

-Show the direction of the flow of Electrons.

Power Supply

20 Amp Fuse

4 Ohms Resistance

900 Watts

A 900 Watt sound system uses drives 4 Ohms of Speakers.

-What is the Voltage and Current for this system at Full Power?

-This system is connected to a 20 Amp fuse. If I increase the Wattage in the system, at what Wattage will push the fuse past 20 Amps? (And “blow the circuit”)

Kirchhoff’s Law

• For any complete Electrical Circuit, the following formulas show the relationship between partial and total volts, resistance, and amps.

• V0 = V1 + V2 + V3

• R0 = R1 + R2 + R3 (In Series)

• A0 = A1 + A2 + A3 (In Parallel)

Coulomb’s Law

• 𝐹 = 𝑘𝑄1𝑄2

𝑟2

• F is the force in Newtons

• Q1 and Q2 are the charges of the two bodies in coulombs

• r is the separation of the two bodies in meters• k is a constant equal to 9 × 109 𝑁𝑚2 ÷ 𝐶2

• (In reality 𝑘 = 8.987552 × 109𝑁𝑚2 ÷ 𝐶2.)

Drift Velocity of Current

Drift Velocity of Current: I = Aenv

• I is the current in amperes and

• A is conductor's cross-sectional Area in square meters

• e is the charge of an electron 1.6 * 10^-19

• n is the number of free electrons / cubic meter of material

• v is the velocity of electron drift

Atmega328 PDIP Chip

Arduino Uno Statistics

Circuit 01 Layout

5V

GND

Pin 9

LED

+ -

330 OhmResistor

Servo Layout

5V

GND

Pin 9

+5 V

Ground

Servo

Arduino in MotionMotors and Servos

Introduction to Robotics and Engineering

Motor or Servo?

Motor

• Faster revolution but less Power

• Speed controlled by varying voltage (Pulse Width Modulation)

• Powered from 5 Volt lead

Servo• Motor combined with

encoder.

• More powerful, but slower

• Two types• Standard: 180 Degree

Rotation• Continuous Rotation

• Three leads:• Signal (from pin)• 5 Volt• Ground

Two Types of Servos

Standard

• Only rotates within a 180 Degree range

• Write Value to Servo –holds the position

• Good for “Armatures”• Hands, Arms

• Holding Devices

Continuous Rotation

• Rotates like a motor –all the way around

• Values written to Servo set “speed”• 0 -> Full

Counterclockwise• 180 -> Full Clockwise

• Good for drive systems• Wheels, Rollers

Single Power Source Setup

External Power Source Servo Setup

Servo CommandsServo Library: Must have this line in the

beginning of each program

#include <Servo.h>

To Create Instance of Servo Object:

(myServo can be any name)

Servo myServo;

To Attach a Servo to a Pin:

myServo.attach(9);

To Start Servo:

myServo.write(0);

Piezo Layout

5V

GND

Pin 13

Piezo

+

Piezo and Potentiometer Layout

5V

GND

Pin 13

Piezo

+

+5 V

Ground

A0

Adruino Piezo and Tone Function

Electronics I

Marist School

tone(pin, frequency, duration)

Use with Arrays

Function with tone and array:

Port Assignments for Pre-Programmed Arduino

• D2: LED On

• D3: LED On

• D4: LED On

• D5: Tone(5, 259)

• D6: LED On / Off 1000 ms

• D7: LED On / Off 1000 ms

• D8: LED On / Off 1000 ms

• D9: LED On / Off 1000 ms

• D10: Servo 180

• D11: Servo 180

• D12: Servo 0

• D13: Servo 0

Build #1: Create a sculpture or device with Pre-Programmed Arduino

• Design Process• Requirements

• Design

• Implementation

• Test

• Download Sample Code to Arduino

Steps to Download Sample Code

• Go to: http://nebomusic.net/arduinolessons/Arduino_Preset.txt

• Copy the text

• Open Arduino Sketch

• Paste the text into an Arduino Sketch document

• Plug in Arduino Uno via USB cable

• Download the Sample Code using the Download icon.

Design Process

• Design: (How will the device by built?) (How will these match with the requirements)

Design Process

• Requirements: (What will the device do?)

Java Programming andSerial Printing with Arduino

Mr. Michaud

Marist School

Serial Communication

• Sends data between devices

• Communication rate is measured in bits per second. Called “Baud”

• Arduino Uno – default is 9600 bits per second.

• 8 bits make a byte

• A byte is one character (Char)

Key Functions

• void setup()• Must be defined

• Runs one time

• Acts like a constructor in Java

• void loop()• Must be defined

• Runs continuously (In a loop . . .)

• Like the act() method in Greenfoot or Gridworld

Serial Functions

• Serial.begin(9600)• Initiates Serial Communication at 9600 Baud

• Called in setup() function

• Serial.println(<string>)• Prints string to console

• Example: Serial.println(“Hello”);

• Serial.println(<number>)• Prints number to console

Example Code

Data Types and Variables

Operators

Declaring Variables and Arrays

Variables:

int myAge = 14; // Integer

float angle = 2*PI; // Float

String name = “Mr. Michaud”;

Arrays:

int pins [] = {3, 4, 5, 6};

String gospels [] = {“Matthew”, “Mark”, “Luke”, “John”};

For Loop

• Repeats section of code while counting up or down with an index variable

• Example

for (int i = 0; i < 10; i++) {

Serial.println(i);

}

Returns:0123456789

for (int i = 0; i < 10; i++) {}

• i++ means "i = i + 1"

• int i means "integer i"

• for (int i = 0; i < 10; i++) means "For index variable istarting at 0, while i is less than 10, count be 1."

Combined For Loop and Array

Conditional Statements

• ‘if statement’: Checks if a given statement or expression is true and then executes a section of code

if (score > 9) {

Serial.println(“You Win”);

}

While Loop

• Executes a Segment of Code while a Condition is True

References

• Key Vocabulary: (http://docs.oracle.com/javase/tutorial/java/nutsandbolts/index.html)

• Another Good Reference: http://processing.org/reference/

Arduino Key FunctionsLED Blink Projects

Pin Output Control and Timing

• pinMode(pin, Mode)

pinMode(3, OUTPUT);

• digitalWrite(pin, State)

digitalWrite(3, HIGH);

digitalWrite(3, LOW);

• delay(milliseconds)

delay(1000);

Program Control

• Two Key Functions in all Arduino Programs:

Sample Program

Declare and set variables pointing to pins.

setup() sets the pin mode to output –send signals.

loop() repeats turning on, then off the lights at ½ second intervals

For Loop

• Used to repeat a set of commands

for (int i = 0; i < 8; i++) {

// repeated commands

}

Means:

“Set i to zero. While i is less than 8, add 1 to i.”

This sequence will loop 8 times:

“0, 1, 2, 3, 4, 5, 6, 7”

Example:

Adruino Piezo and Tone Function

Electronics I

Marist School

tone(pin, frequency, duration)

Use with Arrays

Function with tone and array:

Pitch Chart:

Single Power Source Setup

External Power Source Servo Setup

Servo CommandsServo Library: Must have this line in the

beginning of each program

#include <Servo.h>

To Create Instance of Servo Object:

(myServo can be any name)

Servo myServo;

To Attach a Servo to a Pin:

myServo.attach(9);

To Start Servo:

myServo.write(0);

Programming: Input

• Principle: Take incoming electrical current and vary the resistance to get different voltage levels.

• Arduino reads these different voltage levels in the Analog pins and assigns a number ranged from 0 to 1023 for voltage level.

• Map the incoming voltage (0-1023) to a function or algorithm to invoke action.

Sensors and Arduino

• Sensor Value is read through Analog input pins A0, A1, A2, A3, A4, and A5

• Value is taken as input of 0 to 5 volts and converted to a 10 bit depth number. (0 to 1024).

• analogRead(pinNumber) function will return to the program an integer between 0 and 1024.

• Sensors work by varying resistance in the circuit, resulting in a varying the voltage sent to the Analog input pins.

Piezo and Potentiometer Layout

5V

GND

Pin 13

Piezo

+

+5 V

Ground

A0

Pushbutton Sensor: Analog Mode

Pushbutton Sensor: Digital Mode

Microphone

Build #2: Design a sculpture / device with your own programming

• Design Process:• Requirements

• Design

• Implementation

• Test

Design Process

• Design: (How will the device by built?) (How will these match with the requirements)

Design Process

• Requirements: (What will the device do?)

Tools: Fritzing: Layout and Schematic diagrams for circuits

Other Arduino Applications

• Sound: Minim

• Computer Vision with Processing

• Arduino as extension of PC using Processing (motor controller)