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Building an alarm clock with node.js or Hacking vs. Engineering Felix Geisendörfer 29.09.2011 (v1) Donnerstag, 29. September 2011
Building an alarm clock with node.js
or
Hacking vs. Engineering
Felix Geisendörfer 29.09.2011 (v1)Donnerstag, 29. September 2011
TextWelcome to the Siesta
right-after-lunch Session!Donnerstag, 29. September 2011
Building an alarm clock with node.js
or
Hacking vs. Engineering
Felix Geisendörfer 29.09.2011 (v1)Donnerstag, 29. September 2011
@felixge
Twitter / GitHub / IRC
Donnerstag, 29. September 2011
My Problem
• Getting up early in the morning
• That means before 12:00 (noon)
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This talk
• How I solved this problem
• Hacking vs. Engineering the solution
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Patient History
• 23 years
• Working from home
• Can work any hours
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So why get up early?
• To get more stuff done ...
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Previous attempts
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Behavioral ConditioningDonnerstag, 29. September 2011
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Flying alarm clockDonnerstag, 29. September 2011
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Circadian rhythm app (Sleep Cycle)Donnerstag, 29. September 2011
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Many alarmsDonnerstag, 29. September 2011
Nothing was working
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Text
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VLCDonnerstag, 29. September 2011
pmsetDonnerstag, 29. September 2011
The Script
https://gist.github.com/1a40a207cf6132f77efa
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sudo ./alarm.js 7 30
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Result
• Reliably waking up at any time
• Get to choose different music every night
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Hacking vs. Engineering
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(Software) Engineering
“Rigorous application of science”
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Hacking
“Playful cleverness”
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Hacking vs. Engineering this project
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Tests?
Engineering: Yes
Hacking: Maybe
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Airtunes?Engineering:
Implement protocol
Hacking:
Piggyback on iTunes or VLC
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Codevar file = '/my/music/file.mp3';var vlcPath = '/Applications/VLC.app/Contents/MacOS/VLC';var vlc = spawn(vlcPath, [ '-R', '--sout=#transcode {acodec = alac channels = 2, samplerate = 44100}: raop{host=10.0.1.13,volume=255}', file]);
vlc.stdout.setEncoding('utf8');vlc.stderr.setEncoding('utf8');vlc.stdout.on('data', process.stdout.write);vlc.stderr.on('data', process.stderr.write);
vlc.on('exit', function(code, signal) { console.log('vlc exit: %i %s', code, signal);});
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Wakeup from Sleep?
Engineering:
pmset schedule wakeorpoweron <datetime>
Hacking:
pmset schedule wakeorpoweron MTWRFSU <time>
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Code
var powerCmd = sprintf( 'pmset repeat wakeorpoweron MTWRFSU %02d:%02d:00', powerHour, powerMinute);
exec(powerCmd, function(err) { if (err) throw err; process.setuid('felix');});
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Turn off speakers?
Engineering:
Install speakers in unreachable place.
Hacking: ?
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Text
Duct TapeDonnerstag, 29. September 2011
Duct Tape of Concurrent I/ODonnerstag, 29. September 2011
Engineering Solution for ConcurrencyDonnerstag, 29. September 2011
Why am I talking about this?
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JS has a very hacker-driven culture
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Duct tape of the webDonnerstag, 29. September 2011
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Duct tape of the DOMDonnerstag, 29. September 2011
• Hacking is lots of fun, go do it!
• Hacking can be a good solution!
• But be aware that many problems call for an engineering approach.
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Where we need more engineering:
• Libraries
• Domain logic
• Performance
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TL;DL
• Hack when in doubt
• Engineer when clear
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EngineeringHacking
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Questions?
☝@felixge
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