Meeting 2: Week 1, Long day (Thursday January 30 2:40 – 5:20)

Announcements
 
  • New people: You are responsible for knowing what we covered in our first meeting. (Even better, you should be proactive, and ask the professor of a class you join late if there is anything you need to do to catch up.) Read the syllabus at wp.nyu.edu/abudhabi_im_intro
  • WordPress: Everyone should have received an invitation.
  • You will all need to undergo training to use the tools in the IM lab. We have scheduled 3 sections of tool training for this coming Sunday, Feb 2nd. You should sign up for the training as soon as possible as availability will become quite limited as the semester progresses. If you did this training last semester you don’t need to do it again.
  • The IM program is seeking:
  • Good lab citizenship: clean up after yourselves: kits, food, papers, etc. even if it’s not yours.
  • Remember that if you drop the class you must return the kit
Activity: Simple circuit
 
  • Kits
  • Simple circuit using Arduino and power supply

Lecture

Electricity – its magic!

    • We can predict what it will do quite accurately, but don’t really understand it what is it
    • Flow of electrons
      • want to move from place of higher potential energy to place of lower potential energy
      • like a rock or water falling from a cliff 
      • unlike a rock or water, electricity needs a conductive material
    • AC vs. DC – very briefly, will discuss more as it comes up
    • What makes a circuit?
      • Something to provide energy (battery, power supply, USB port; sometimes called the source) – in our case your laptop via the Arduino
        • What is the Arduino doing in this case?
      • Components or other things that usually convert electrical energy to some other form of energy (e.g. light, sound, heat, movement) 
      • Conductors to connect – the wires
      • Optionally, switches or other devices to control the flow of energy
  • In our circuit the resistor is controlling the brightness of the LED so that it doesn’t burn out

Schematics

  • Introduction to schematics: Important part of something, without getting distracted by details (e.g. subway maps)
    • power
    • gnd
    • resistor
    • LED

Activity: Switches

 
  • What if we want to turn it the LED on and off?
    • Pull out a wire
    • That’s a switch, but a pretty inconvenient one 
      • Schematic symbol of switch
    • How does it work?
      • Breaks the flow of electrons by breaking the continuous path
      • Doesn’t electricity (the electrons) just flow out the end of the wire?
      • The switch can go on either side. How is this possible?
    • Let’s use a real switch
      • How is this switch different from the earlier switch?
      • Schematic symbol of momentary switch

Series and Parallel 

    • What if we put two switches in?
      • Series and parallel
      • Schematics
 
Lecture: Review and Theory
 
  • Review basic circuit and the concept of a switch
  • Ohm’s law
    • i=v/r
    • The math only works for linear components (note circular definition) like resistors, but the principle is the same for non-linear components and is very important:
    • For a given resistance, the higher the pressure (voltage), the higher the current
    • For a given voltage, the higher the “resistance”, the lower the current
  • Everything needs to be used up. In other words, if you go around a loop it must add up to zero
    • Source (pump)
    • Voltage drops (according to Ohm’s law- v=i*r)
    • Load
    • Short circuit

Review of how to build circuits

Introduction to Arduino

  1. Install the Arduino IDE from https://www.arduino.cc/en/Main/Software
  2. Upload the Blink example
  3. Change the parameter in delay()
  4. Upload again and verify that the LED blinks at the new rate

Clean up

Assignment due Tuesday February 4
(Updated January 31)
 
  • Label your shelves. Note that some tape falls off easily so make sure it stays on. 
  • The NYU WordPress site has too many technical problems so we will not use it for your assignments. Instead prepare the information on your computer, but don’t hand it in yet. We will do that in class on Tuesday.
    • Save any text as a text only file
    • Save any images as JPG or PNG
    • Save any video to Youtube or Vimeo
  • Make a switch that doesn’t use your hands. Remember that most metals conducts electricity, and most non-metals don’t (there are some exceptions).
    • Write a description of your switch
    • Prepare two images of your switch: one close up of the switch, one to include the whole setup. Save the images as JPG or a PNG
    • Prepare a short video showing your switch in operation. Save this on Youtube or Vimeo.
    • Be  prepared to demonstrate your switch in class next week.
  • Observe something “interactive” on campus somewhere. Pay attention to what works and what doesn’t, and think about the design decisions and constraints. Write two paragraphs about this.
     
  • Examples: