Meeting 10: Week 5, Long day (Thursday February 27 2:40 – 5:20)

Lecture

  • Motors
    • Arduino current limitations
      • Remember I=V/R
        • “LEDs” have high “resistance”, so consume low current (for a given voltage)
        • Motors have low “resistance”, so consume high current 
      • Current flowing through any resistance causes heat
        • Everything has resistance
          • Therefore, where electricity is flowing there will be heat
      • Heat causes damage 
      • Arduino does not limit current, it is damaged by too much current
  • Transistors
  • Power
  • H-bridge

Construction Techniques

Do not solder jumper cables!

  1. Solid wire vs. Stranded wire
  2. Panel mounted components vs. printed circuit board PCB mounted components
  3. Front panels
    1. Laser cut acrylic, hand drilled wood, cardboard
    2. Panel mounted potentiometers and switches. Do not use PCB mounted components
    3. Servo motors
    4. LEDs

Demo

  1. Soldering
    1. Wires to wires
    2. Heat shrink tubing

    3. Do not solder jumper cables!

    4. Wires to potentiometers and switches

    5. Do not solder jumper cables!

    6. Do not solder jumper cables!

  2. Next time
    1. Scrap wood
    2. Adding wires to LEDs
    3. Cardboard front panels
    4. Hot glue and rubbing alcohol
    5. Strain relief
    6. Panels

Homework for Tuesday March 3

  1. We will use this session to work on your projects. Ideally you will come with your project underway, ready to ask me questions (if you have any).
  2. I have made some minor changes to the project definition, which is still at the bottom of last Tuesday’s lecture notes