Microcontrollers

And the "Hello World" of Hardware

specifically an Arduino Uno R3

What is a microcontroller?

• a "dedicated" computer
• you need another system to "program" them (you don't power them up and start typing)
• often embedded in a device, sometimes called "embedded controller"
• low power
• tend to be small, cheap
• often are "ruggedized"
• dedicated input device, sometimes has LCD output

Arduino (UNO R3)

• board ~$25-30
• an A-B USB cable for power and data transfer ~$4
• your trusty laptop with the Arduino IDE
• breadboard - they are awesome! ~$5
• m-m breadboard wires - lots for ~$5
• an LED and "matching" resister - lots for ~$30

All items Available at Adafruit and Sparkfun

A blinky led is the

"Hello World" of Hardware

Hardware setup

• Pins are helpfully marked on the board!
  • docs - click documentation, go to "Input and Output" for more pin information
  • "Each of the 14 digital pins on the Uno can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts."
• Digital Pin ~3 => resistor => LED => GND

Software Setup

• Arduino IDE - Integrated Development Environment
  • really just a fancy text editor that "knows" about code, might do some extra stuff
• Arduino has it's own language - reference
• We will use the following functions:
  • `setup() {}` and `loop() {}`
  • `pinMode(pin, mode)` - in setup
  • `digitalWrite(pin, value)` - in loop
  • `delay(milliseconds)` - in loop

void setup() {
  // put your setup code here, to run once:
  pinMode(3, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(3, HIGH);
  delay(500);
  digitalWrite(3, LOW);
  delay(500);
}

Demo

Emily Platzer

• @emilyplatzer
• github.com/craftninja
• emilyplatzer.com