Lock in $30 Savings on PRO—Offer Ends Soon! ⏳
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
200
Migratory Patterns - KubeCon Salt Lake City, 2024
phodgson
0
150
A Journey Into Feature Toggles - OSCON Austin 2017
phodgson
5
660
Test-driven Client-side JS
phodgson
5
870
Functional Reactive JavaScript
phodgson
8
820
different.js - Forward JS 2014
phodgson
4
850
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
TUIライブラリつくってみた / i-just-make-TUI-library
kazto
1
360
CSC305 Lecture 17
javiergs
PRO
0
340
안드로이드 9년차 개발자, 프론트엔드 주니어로 커리어 리셋하기
maryang
1
110
複数人でのCLI/Infrastructure as Codeの暮らしを良くする
shmokmt
5
2.2k
20 years of Symfony, what's next?
fabpot
2
340
LLMで複雑な検索条件アセットから脱却する!! 生成的検索インタフェースの設計論
po3rin
2
640
sbt 2
xuwei_k
0
250
AIコードレビューがチームの"文脈"を 読めるようになるまで
marutaku
0
350
モデル駆動設計をやってみようワークショップ開催報告(Modeling Forum2025) / model driven design workshop report
haru860
0
260
ID管理機能開発の裏側 高速にSaaS連携を実現したチームのAI活用編
atzzcokek
0
210
配送計画の均等化機能を提供する取り組みについて(⽩⾦鉱業 Meetup Vol.21@六本⽊(数理最適化編))
izu_nori
0
140
C-Shared Buildで突破するAI Agent バックテストの壁
po3rin
0
370
Featured
See All Featured
Helping Users Find Their Own Way: Creating Modern Search Experiences
danielanewman
31
3k
How Fast Is Fast Enough? [PerfNow 2025]
tammyeverts
3
390
Sharpening the Axe: The Primacy of Toolmaking
bcantrill
46
2.6k
The Hidden Cost of Media on the Web [PixelPalooza 2025]
tammyeverts
1
93
Evolution of real-time – Irina Nazarova, EuRuKo, 2024
irinanazarova
9
1.1k
VelocityConf: Rendering Performance Case Studies
addyosmani
333
24k
Fireside Chat
paigeccino
41
3.7k
Building Better People: How to give real-time feedback that sticks.
wjessup
370
20k
Designing for Performance
lara
610
69k
A designer walks into a library…
pauljervisheath
210
24k
[SF Ruby Conf 2025] Rails X
palkan
0
490
Into the Great Unknown - MozCon
thekraken
40
2.2k
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