Know How...

Mar 6th 2014

Know How... 83

Linux on a USB and Sound Controlled LED

Why you should understand DNS, make a bootable Linux OS on a USB, and control a string of LED's using TIP31 transistors.
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Why you should understand DNS, make a bootable Linux OS on a USB, and control a string of LED's using TIP31 transistors. Check out our transcripts.

Making a Bootable Linux USB Drive

Step 1: Get a USB Drive

- You'll need a USB flash drive of at least 2GB or more. - Format the USB Drive by using Disk Utility and use MS-DOS (FAT)

Step 2: Download the USB Loader

- Go to Seven Bits Mac-Linux USB Loader to download the software. - Download the Distribution of Linux of your choice, I chose Ubuntu - Create Live USB **This process should only take about ten to fifteen minutes.

Step 3: Reboot

- Reboot your Mac, on startup when you hear the "chime" hold the "alt / option" key to choose your boot method - Select your USB Drive, press 1 to load Linux. - Congrats you have a portable USB OS! Links: Seven Bits Mac-Linux USB Loader Mac-Linux USB Loader on GitHub

LED lights & TIP31 Transistors

LED Lights

* LED stands for "Light Emitting Diode" * Diodes only allow current to pass in one direction - positive to negative * LEDs are low-cost, efficient light sources * SMD (Surface Mount) LEDs can be found in rolls backed with adhesive

TIP31 Transistor

* It's a NPN (Negative-Positive-Negative) bipolar junctions used for medium power applications. * We're using a TIP31C -- which is capable of 100v and 40 Watts * Pin 1 and 3 are a junction. Used by a lower-power circuit. * Pin 2 and 3 is a semi-conductive pathway. * When a charge passes between junction 1 and 3, it allows a charge to pass between 2 and 3. * Where this becomes useful is that the charge passing between pin 1 and 3 can be small while the charge passing between pin 2 and 3 can be large. ** The voltage from the headphone hack of a media play is 1-2 volts, perhaps 20ma. That would never be enough to drive a LED strip. ** HOWEVER... we can use that small current between pins 1 and 3, to trigger a much larger current between pins 2 and 3. ** If pins 2 and 3 are the negative side of a 12 volt, 2 amp circuit, then we've just created something useful!

Sound-Sensitive LED Lights

Parts List

Tool List

  • Soldering Iron
  • Scissors
  • Wire Stripper/Clipper
  • Lighter
  • "Helping Hands"
  • Needle-nose Pliers

The Process

Dancing LED Schematic

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