Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Building Your Own Lightsaber
Search
Pete Hodgson
January 03, 2014
Programming
104
6.4k
Building Your Own Lightsaber
Presented at CodeMash 2014
Pete Hodgson
January 03, 2014
Tweet
Share
More Decks by Pete Hodgson
See All by Pete Hodgson
Feature Flags Suck! - KubeCon Atlanta 2025
phodgson
0
160
Migratory Patterns - KubeCon Salt Lake City, 2024
phodgson
0
140
A Journey Into Feature Toggles - OSCON Austin 2017
phodgson
5
650
Test-driven Client-side JS
phodgson
5
870
Functional Reactive JavaScript
phodgson
8
810
different.js - Forward JS 2014
phodgson
4
840
Railsconf2014
phodgson
7
1.5k
iOS Unit Testing Workshop
phodgson
3
550
Multi-platform Mobile with Calatrava - May 2013
phodgson
2
550
Other Decks in Programming
See All in Programming
JEP 496 と JEP 497 から学ぶ耐量子計算機暗号入門 / Learning Post-Quantum Crypto Basics from JEP 496 & 497
mackey0225
2
460
PHPライセンス変更の議論を通じて学ぶOSSライセンスの基礎
matsuo_atsushi
0
170
目的で駆動する、AI時代のアーキテクチャ設計 / purpose-driven-architecture
minodriven
10
3.3k
Promise.tryで実現する新しいエラーハンドリング New error handling with Promise try
bicstone
3
1.5k
FlutterKaigi 2025 システム裏側
yumnumm
0
1.2k
[堅牢.py #1] テストを書かない研究者に送る、最初にテストを書く実験コード入門 / Let's start your ML project by writing tests
shunk031
11
5.7k
Java_プロセスのメモリ監視の落とし穴_NMT_で見抜けない_glibc_キャッシュ問題_.pdf
ntt_dsol_java
0
230
イベントストーミングのはじめかた / Getting Started with Event Storming
nrslib
1
680
モデル駆動設計をやってみよう Modeling Forum2025ワークショップ/Let’s Try Model-Driven Design
haru860
0
180
CSC509 Lecture 13
javiergs
PRO
0
260
オフライン対応!Flutterアプリに全文検索エンジンを実装する @FlutterKaigi2025
itsmedreamwalker
2
260
しっかり学ぶ java.lang.*
nagise
1
420
Featured
See All Featured
Context Engineering - Making Every Token Count
addyosmani
9
410
ピンチをチャンスに:未来をつくるプロダクトロードマップ #pmconf2020
aki_iinuma
127
54k
Building an army of robots
kneath
306
46k
Templates, Plugins, & Blocks: Oh My! Creating the theme that thinks of everything
marktimemedia
31
2.6k
Making Projects Easy
brettharned
120
6.5k
How Fast Is Fast Enough? [PerfNow 2025]
tammyeverts
3
340
Site-Speed That Sticks
csswizardry
13
970
Fireside Chat
paigeccino
41
3.7k
CSS Pre-Processors: Stylus, Less & Sass
bermonpainter
359
30k
KATA
mclloyd
PRO
32
15k
A better future with KSS
kneath
239
18k
Principles of Awesome APIs and How to Build Them.
keavy
127
17k
Transcript
Building your own Lightsaber
me me me Pete Hodgson Consultant at ThoughtWorks @ph1 blog.thepete.net
TSA Pro-Tip™
None
None
Green Field http://www.flickr.com/photos/jillclardy/3213748255
Continuous Integration
Feedback
None
Feedback
http://www.flickr.com/photos/johnmueller/52621490/ what if you have no build box?
None
Raspberry Pi
None
Raspberry Pi
visual indicator aka build light
None
None
Build Light
Pretending to work
raspberry pi & build light
done.
done. ?
build light build my own lightsaber
Learning by Doing
Learning Doing
Learning Doing Learning By Doing
Choose a “right-sized“ problem
build light build my own lightsaber
LEDs low voltage (can be powered via USB) bright flexible
(blinky! colors!)
all the colors
The Drefus Model
Beginner Expert
Beginner detailed step-by-step instructions no wider context
Beginner detailed step-by-step instructions no wider context Expert wider context
(goal) no details (yet)
Know where you are on the Drefus scale
None
all the colors
multi-color LEDs Search
multi-color LEDs Search an LED can only be one color…
but LEDs can come in many colors… solution: combine different colored LEDs
RGB color mixing
vary LED brightness Search
vary LED brightness Pulse Width Modulation P W M Search
Incandescent Bulb Voltage Brightness
LED Voltage Brightness
voltage 100% 0% time brightness: 100%
voltage 100% 0% time
50% on 50% off duty cycle voltage 100% 0% time
50% on 50% off duty cycle brightness: 50% voltage 100%
0% time
voltage 100% 0% time
25% on 75% off voltage 100% 0% time
brightness: 25% 25% on 75% off voltage 100% 0% time
Don't trust your intuition '
Red LED + Green LED + Blue LED + PWM
= all the colors!
None
Raspberry PI red LED green LED blue LED PWM
GPIO Pins
Raspberry Pi has two GPIO pins which capable of PWM
output. Our light needs three.
Arduino
Arduino is an Open-Source electronics prototyping platform based on flexible,
easy-to-use hardware and software. - arduino.cc
Arduino
Raspberry PI red LED green LED blue LED PWM
Raspberry PI red LED green LED blue LED PWM Arduino
???
Feature-creep as a learning tool
Raspberry PI red LED green LED blue LED PWM Arduino
???
None
baby steps, towards an eventual goal.
sketch 1 blinking an LED (Hello World of hardware)
None
IO pin ground pin
None
pin “high” (+ve voltage)
pin “low” (0 voltage)
int LED_PIN = 6;! ! void setup() { ! pinMode(LED_PIN,
OUTPUT); ! }! ! void loop() {! digitalWrite(LED_PIN, HIGH);! delay(1000); ! digitalWrite(LED_PIN, LOW);! delay(1000); ! }!
sketch 2 fading an LED (PWM)
None
int LED_PIN = 6;! int MAX_BRIGHTNESS = 255;! int brightness
= 0;! ! void setup() { ! pinMode(LED_PIN, OUTPUT); ! }! ! void loop() {! analogWrite(LED_PIN, brightness);! ! brightness = brightness + 5;! if( brightness > MAX_BRIGHTNESS )! brightness = 0;! ! delay(30);! }!
int LED_PIN = 6;! int MAX_BRIGHTNESS = 255;! int brightness
= 0;! ! void setup() { ! pinMode(LED_PIN, OUTPUT); ! }! ! void loop() {! analogWrite(LED_PIN, brightness);! ! brightness = brightness + 5;! if( brightness > MAX_BRIGHTNESS )! brightness = 0;! ! delay(30);! }! PWM
sketch 3 mixing colors
None
None
None
int RED_PIN = 3;! int GREEN_PIN = 5;! int BLUE_PIN
= 6;! int MAX_BRIGHTNESS = 255;! ! void setup() { ! pinMode(RED_PIN, OUTPUT );! pinMode(GREEN_PIN, OUTPUT );! pinMode(BLUE_PIN, OUTPUT );! }! ! void loop() {! byte color[3];! assignRandomColorTo(color);! displayColor(color);! delay(1000); ! }! ! void assignRandomColorTo(byte colorComponents[]){! colorComponents[0] = random(MAX_BRIGHTNESS);!
int RED_PIN = 3;! int GREEN_PIN = 5;! int BLUE_PIN
= 6;! int MAX_BRIGHTNESS = 255;! ! void setup() { ! pinMode(RED_PIN, OUTPUT );! pinMode(GREEN_PIN, OUTPUT );! pinMode(BLUE_PIN, OUTPUT );! }! ! void loop() {! byte color[3];! assignRandomColorTo(color);! displayColor(color);! delay(1000); ! }! ! void assignRandomColorTo(byte colorComponents[]){! colorComponents[0] = random(MAX_BRIGHTNESS);!
int RED_PIN = 3;! int GREEN_PIN = 5;! int BLUE_PIN
= 6;! int MAX_BRIGHTNESS = 255;! ! void setup() { ! pinMode(RED_PIN, OUTPUT );! pinMode(GREEN_PIN, OUTPUT );! pinMode(BLUE_PIN, OUTPUT );! }! ! void loop() {! byte color[3];! assignRandomColorTo(color);! displayColor(color);! delay(1000); ! }! ! void assignRandomColorTo(byte colorComponents[]){! colorComponents[0] = random(MAX_BRIGHTNESS);!
! void loop() {! byte color[3];! assignRandomColorTo(color);! displayColor(color);! delay(1000); !
}! ! void assignRandomColorTo(byte colorComponents[]){! colorComponents[0] = random(MAX_BRIGHTNESS);! colorComponents[1] = random(MAX_BRIGHTNESS);! colorComponents[2] = random(MAX_BRIGHTNESS);! }! ! void displayColor(byte colorComponents[]){! analogWrite( RED_PIN, colorComponents[0] );! analogWrite( GREEN_PIN, colorComponents[1] );! analogWrite( BLUE_PIN, colorComponents[2] ); ! }!
! void loop() {! byte color[3];! assignRandomColorTo(color);! displayColor(color);! delay(1000); !
}! ! void assignRandomColorTo(byte colorComponents[]){! colorComponents[0] = random(MAX_BRIGHTNESS);! colorComponents[1] = random(MAX_BRIGHTNESS);! colorComponents[2] = random(MAX_BRIGHTNESS);! }! ! void displayColor(byte colorComponents[]){! analogWrite( RED_PIN, colorComponents[0] );! analogWrite( GREEN_PIN, colorComponents[1] );! analogWrite( BLUE_PIN, colorComponents[2] ); ! }!
! void loop() {! byte color[3];! assignRandomColorTo(color);! displayColor(color);! delay(1000); !
}! ! void assignRandomColorTo(byte colorComponents[]){! colorComponents[0] = random(MAX_BRIGHTNESS);! colorComponents[1] = random(MAX_BRIGHTNESS);! colorComponents[2] = random(MAX_BRIGHTNESS);! }! ! void displayColor(byte colorComponents[]){! analogWrite( RED_PIN, colorComponents[0] );! analogWrite( GREEN_PIN, colorComponents[1] );! analogWrite( BLUE_PIN, colorComponents[2] ); ! }!
! void loop() {! byte color[3];! assignRandomColorTo(color);! displayColor(color);! delay(1000); !
}! ! void assignRandomColorTo(byte colorComponents[]){! colorComponents[0] = random(MAX_BRIGHTNESS);! colorComponents[1] = random(MAX_BRIGHTNESS);! colorComponents[2] = random(MAX_BRIGHTNESS);! }! ! void displayColor(byte colorComponents[]){! analogWrite( RED_PIN, colorComponents[0] );! analogWrite( GREEN_PIN, colorComponents[1] );! analogWrite( BLUE_PIN, colorComponents[2] ); ! }!
Raspberry PI red LED green LED blue LED PWM Arduino
???
Raspberry PI red LED green LED blue LED PWM Arduino
???
Raspberry PI red LED green LED blue LED PWM Arduino
serial
sketch 4 an echo server (serial IO)
void setup()! {! Serial.begin(57600); // start serial port at 57600
bps! }! ! void loop() {! waitForInput();! ! static char input[1025];! int bytesRead = Serial.readBytesUntil( '\n', input, 1024 );! ! if( bytesRead ){! String str = String(input);! str.toUpperCase();! Serial.println(str);! }! }! ! void waitForInput() {! while (Serial.available() <= 0) {! // busy loop! }! }!
void setup()! {! Serial.begin(57600); // start serial port at 57600
bps! }! ! void loop() {! waitForInput();! ! static char input[1025];! int bytesRead = Serial.readBytesUntil( '\n', input, 1024 );! ! if( bytesRead ){! String str = String(input);! str.toUpperCase();! Serial.println(str);! }! }! ! void waitForInput() {! while (Serial.available() <= 0) {! // busy loop! }! }!
void setup()! {! Serial.begin(57600); // start serial port at 57600
bps! }! ! void loop() {! waitForInput();! ! static char input[1025];! int bytesRead = Serial.readBytesUntil( '\n', input, 1024 );! ! if( bytesRead ){! String str = String(input);! str.toUpperCase();! Serial.println(str);! }! }! ! void waitForInput() {! while (Serial.available() <= 0) {! // busy loop! }! }!
void setup()! {! Serial.begin(57600); // start serial port at 57600
bps! }! ! void loop() {! waitForInput();! ! static char input[1025];! int bytesRead = Serial.readBytesUntil( '\n', input, 1024 );! ! if( bytesRead ){! String str = String(input);! str.toUpperCase();! Serial.println(str);! }! }! ! void waitForInput() {! while (Serial.available() <= 0) {! // busy loop! }! }!
void setup()! {! Serial.begin(57600); // start serial port at 57600
bps! }! ! void loop() {! waitForInput();! ! static char input[1025];! int bytesRead = Serial.readBytesUntil( '\n', input, 1024 );! ! if( bytesRead ){! String str = String(input);! str.toUpperCase();! Serial.println(str);! }! }! ! void waitForInput() {! while (Serial.available() <= 0) {! // busy loop! }! }!
void setup()! {! Serial.begin(57600); // start serial port at 57600
bps! }! ! void loop() {! waitForInput();! ! static char input[1025];! int bytesRead = Serial.readBytesUntil( '\n', input, 1024 );! ! if( bytesRead ){! String str = String(input);! str.toUpperCase();! Serial.println(str);! }! }! ! void waitForInput() {! while (Serial.available() <= 0) {! // busy loop! }! }!
Raspberry PI red LED green LED blue LED PWM Arduino
serial
GPIO Pins
Raspberry PI red LED green LED blue LED Arduino
Raspberry PI red LED green LED blue LED Arduino “ffaa11\n”
Raspberry PI red LED green LED blue LED Arduino “ffaa11\n”
Raspberry PI red LED green LED blue LED Arduino “ffaa11\n”
Much Learning Arduino- compatibles bareduinos LPC810 soldering! transistors protoboard fritzing
voltage regulators node.js cctray line-level converters command-line builds C++ on Arduino usb to serial external programmers OSS hardware
Resources
Resources
moredip/aphex (work in progress)
Have FUN!
Pete Hodgson @ph1
[email protected]
these slides http://bit.ly/buildlightsaber