Westerville Schools 2019

Reference material and notes for electronics workshop conducted for Westerville schools August 2019.

Outline

  1. A few orientation questions
  2. Overview of the three hardware platforms
  3. Setup and programming each platform, first pass
  4. Looking deeper at the electronics of these platforms
  5. Adding input/output hardware and libraries
  6. Problem-driven processes
  7. Additional resources

Hardware Platforms Notes

All three are excellent open platforms for learning physical computing but each has its own niche

Microbit

Pros:

  • easiest to get started with, no drivers install, no software to install, no hardware setup
  • on board accessories
  • many educational examples at middle school level

Cons:

  • poor expandability due to form factor and IO pins
  • questionable Bluetooth compatibility
  • single hardware platform
  • uneven availability
  • not 5v tolerant
  • poor on board power output 5ma per pin, ~90ma total

Best for: middle school level, quick workshops, using just the board or with select accessories.

Arduino Uno / Mega

Pros:

  • most mature and widely supported with resources
  • least expensive (generic)
  • many hardware variations and alternative implementations
  • conventional IO access and form factors
  • 5v system throughout (in traditional form)

Cons:

  • least capability
  • no accessories on board
  • no connectivity
  • fading in popularity

Best for: all ages, moderate length to lifelong learning opportunities, open ended experimentation with physical computing that does not require connectivity or advance processing.

Raspberry Pi 3 B+

Pros:

  • much more powerful: can do machine vision and video processing
  • uses standard computer peripherals
  • ethernet, wifi (on some models)
  • standard form factor for board and IO pins
  • a variety of hardware variations
  • well supported with resources

Cons

  • most complex to get started, requires an OS layer
  • requires standard computer peripherals to program
  • consumes the most power
  • just overkill for many physical computing applications
  • the most expensive (at full size)
  • not 5v tolerant

Best for: all ages, extended to life-long learning experiences, applications that require its power and connectivity

Problem-driven processes

What do I use to?

output light (LED, Neopixel, Incandescent, EL wire)

receive input (buttons & switches, potentiometers, touch, keyboards)

display data (on connected PC, on LCD)

measure distance/obstacles (infrared, ultrasonic, Lidar-ish, magnetics)

move something external (motors, servos, solenoids)

power something at more than 5v (transistors, relays, controllers)

measure device orientation/movement (compass, gyro, accelerometers, IMUs, vibration, reed switches)

measure the environment (temp, humidity, moisture, pollutants, location & altitude)

communicate internally (serial, i2C, SPI, PWM, Neopixels, homebrew)

communicate externally (bluetooth, wifi, rfid, infrared, visible light)

What skills and tools will I need?

Critical basic electronics principles

positive is negative, now forget that.

my Aunt is from West/Virginia or what’s a watt?

Ohm’s Law: V = IR aka I = V/R, R = V/I. applications

logic levels

Learn how to read a datasheet, pinout map, and schematic.

Tie all grounds together, test everything, use pullups.

Tools

breadboarding and protoboarding gear

multimeters

power supplies

          magnifying glass/magnifying cameras

           oscilloscopes

           wiring and soldering equipment

What do I do when I have a component with no info?

    1. find data sheet & schematic
      1. study power in & out, including per pin
      2. study data in & out
    2. look at physical mount and pins
    3. decipher extra components (reading SMD codes)
    4. study circuit board traces
    5. test with power supply and multimeter or oscilloscope
    6. test with development board
    7. watch for smoke

 

…and now for something completely different.

Maker Tech Education