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
1
230
Migratory Patterns - KubeCon Salt Lake City, 2024
phodgson
0
180
A Journey Into Feature Toggles - OSCON Austin 2017
phodgson
5
690
Test-driven Client-side JS
phodgson
5
880
Functional Reactive JavaScript
phodgson
8
830
different.js - Forward JS 2014
phodgson
4
860
Railsconf2014
phodgson
7
1.5k
iOS Unit Testing Workshop
phodgson
3
560
Multi-platform Mobile with Calatrava - May 2013
phodgson
2
560
Other Decks in Programming
See All in Programming
360° Signals in Angular: Signal Forms with SignalStore & Resources @ngLondon 01/2026
manfredsteyer
PRO
0
130
CSC307 Lecture 08
javiergs
PRO
0
670
Raku Raku Notion 20260128
hareyakayuruyaka
0
340
MDN Web Docs に日本語翻訳でコントリビュート
ohmori_yusuke
0
650
CSC307 Lecture 04
javiergs
PRO
0
660
Data-Centric Kaggle
isax1015
2
780
QAフローを最適化し、品質水準を満たしながらリリースまでの期間を最短化する #RSGT2026
shibayu36
2
4.4k
疑似コードによるプロンプト記述、どのくらい正確に実行される?
kokuyouwind
0
390
Vibe Coding - AI 驅動的軟體開發
mickyp100
0
180
AI時代のキャリアプラン「技術の引力」からの脱出と「問い」へのいざない / tech-gravity
minodriven
21
7.3k
今こそ知るべき耐量子計算機暗号(PQC)入門 / PQC: What You Need to Know Now
mackey0225
3
380
OCaml 5でモダンな並列プログラミングを Enjoyしよう!
haochenx
0
140
Featured
See All Featured
How to optimise 3,500 product descriptions for ecommerce in one day using ChatGPT
katarinadahlin
PRO
0
3.4k
Reality Check: Gamification 10 Years Later
codingconduct
0
2k
Unlocking the hidden potential of vector embeddings in international SEO
frankvandijk
0
170
SERP Conf. Vienna - Web Accessibility: Optimizing for Inclusivity and SEO
sarafernandez
1
1.3k
Max Prin - Stacking Signals: How International SEO Comes Together (And Falls Apart)
techseoconnect
PRO
0
86
AI: The stuff that nobody shows you
jnunemaker
PRO
2
270
A Modern Web Designer's Workflow
chriscoyier
698
190k
Cheating the UX When There Is Nothing More to Optimize - PixelPioneers
stephaniewalter
287
14k
Practical Orchestrator
shlominoach
191
11k
Agile Leadership in an Agile Organization
kimpetersen
PRO
0
83
16th Malabo Montpellier Forum Presentation
akademiya2063
PRO
0
52
The Illustrated Guide to Node.js - THAT Conference 2024
reverentgeek
0
260
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