Archive for May, 2013

LED cubes and Raspberry Pis…

My plan of making an LED cube with a Raspberry Pi is coming together… been making a list of stuff I need, and looking good resources.

IC 1: Serial in/Parallel out.

Apparently this particular type of IC is called a 74HC595. Found it on a list of popular ICs for Arduino chips. Linked datasheet is helpful to get timings for the chips. Also, the 74×595 is supported by WiringPI, so that’s a drop in library that looks easy to use.

LEDs need resistors to limit current, this explains why, and how to calculate the resistances needed. This explains why resistors appear in multiple component lists, but not the capacitors… but apparently it’s for filtering as well as dampening the surge when the LEDs in a layer kick on.

Random stuff:

 

Still to do:

  1. Order Rasp.PI
  2. Order components other than the blue LEDs that I’m prototyping with
  3. Design the circuit.
  4. Run the circuit by people who know stuff
  5. Find out how to do colour changing for RGB LEDs
  6. PWM stuff?

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OpenVPN & China’s Firewall

Ended up choosing an SSH SOCKS proxy + Tunnelblick because it had the fewest moving parts.

Combined with a passwordless SSH key, I saw this status on Facebook today:

Kyle is truly a computer wizard! as in, his Tunnelblick thingy is working!

Location? China.

Success.

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