Meeting Minutes for 2011-09-28

buildscc | 28 Sep 2011 | | meeting-minutes

09/28/2011

John-Nicholas Furst

Valerie Young

Kyle Brogle

George Silvis

Kyle Brogle


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Meeting Minutes for 2011-09-21

09/21/2011

Kyle Brogle

  • Clue dumps at MIT are starting soon, usually going to be tuesdays at 8pm. They’re held by SIPB, and they talk for next week is going to be on BIT coin, and if you’re interested, contact kyle.

Quinn - executive director of security for IS&T

  • “Key to security is people understanding things” hence want to start doing more awareness workshops. Information Awareness Week: one of things they really want to do is to set up some hacking demonstrations. Set up space in GSU (week of oct. 17th). Looking for things that can be done in 10min (to scare, but minimize pooping of the pants)

Kyle Brogle

  • CTF quals are this weekend! The qualification rounds will run from 8pm friday to 8pm sunday. If you’re interested, contact Kyle or John.

John-Nicholas Furst

  • BUILDS Calendar
    • Calendar is still password protected, should be finished (very) soon.

Valerie Young

  • Musical Stairs
    • Musical stairs will be starting up soon this semester, stay tuned for an email.

Danny Cooper

- Video Game Collective
	- If you like videogames and want to learn how to make one, stop by BUILDS on monday at 7pm.

Dan Ellis

  • 829 Studios Web Development
  • Contact dellis@829llc.com if you’re interested

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Using D-Type Flip Flops for Toggling

When using momentary pushbuttons it is common to want to store and then toggle state. There are a couple of ways to do this, for example, you could using a 555 timer, or construct your own latch/flip-flop. However, the 7400 series of integrated circuits has a few nicely packaged D-Type Flip-Flops which are appropriate for switching. The most appropriate is the 74xx74, which is a dual D-type flip flop with inverted and non-inverted outputs. There are other packages like the 74xx174 which is a quad, but you will need to use your own inverter, such as the 74xx04 or 74xx14, to invert the output. Also the packages with more than 4 D-type flip-flops often share a clock, which means that this method of toggling will not work with them.

Contents

1 Parts and Tools 2 Lets Put it Together! 2.1 Schematic Diagram 2.2 Step By Step 2.3 Video Tutorial 3 Resources 4 Credits

Parts and Tools

  • 1 74xx74 D-Type Flip-Flop (choose your logic level for your own project, LS is TTL logic and HC/HCT are CMOS).
  • 1 74xx14 Hex Inverting Schmitt Trigger(for debouncing)
  • 1 1k Resistor
  • 3 0.1uF Ceramic Capacitor (one for debouncing and two for the ICs)
  • Breadboard (or some other prototyping platform)
  • Momentary Push Button
  • Wire

Lets Put it Together!

Schematic Diagram

Step By Step

Video Tutorial

Resources

Credits

Christopher Woodall - chris.j.woodall gmail.com