Basics of Arduino

• Electricity


  A type of energy, much like heat, gravity, or light
• Electrical energy


  Flows through conductors, like wire and is usually converted into other forms of energy to do something interesting, like turn on a light or make some noise out of a speaker
• Transducers


  Components used to convert other types of energy into electrical energy and vice versa
• Sensors


  Things that convert other forms of energy into electrical energy
• Actuators


  Things that convert electrical energy into other forms of energy
• Circuits


  Closed loops of wire with a power source (like a battery) and something to do something useful with the energy, called a load
• Ground


  The point of least potential energy in a circuit, often represented with a ' – ' or GND
• Direct current (DC)


  Circuits where electricity only flows in one direction
• Alternating current (AC)


  Circuits where electricity changes its direction 50 or 60 times a second
• Current


  The amount of electrical charge flowing past a specific point in your circuit, measured in amperes (A)
• Voltage


  The difference in energy between one point in a circuit and another, measured in volts (V)
• Resistance


  How much a component resists the flow of electrical energy, measured in ohms (Ω)
• There needs to be a complete path from the energy source (power) to the point of least energy (ground) to make a circuit
• All the electrical energy gets used up in a circuit by the components in it
• In any circuit, all of the voltage is converted to another form of energy
• Electrical current will seek the path of least resistance to ground
• If you have a connection that connects power and ground together with no resistance, you will cause a short circuit, and the current will try to follow that path
• In a short circuit, the power source and wires convert the electrical energy into light and heat, usually as sparks or an explosion
• Arduino Uno


  The microcontroller development board that acts as a simple computer
• Breadboard


  A board where electronic circuits can be built without soldering, consisting of rows of holes that allow users to connect wires and components together

  
• Jumper wires


  Used to connect components to each other on the breadboard, and to the Arduino
• Light Emitting Diodes (LEDs)

  A type of diode that illuminates when electricity passes through it, commonly used as indicators on a variety of electronic devices
• Resistors


  Resist the flow of electrical energy in a circuit, changing the voltage and current as a result, measured in ohms (Ω)
• Liquid Crystal Display (LCD)


  A type of alphanumeric or graphic display based on liquid crystals, typically has 2 lines able to display 16 characters each

  
• Resistor color code

  Resistor values are marked using colored bands, with each color corresponding to a number

  
• Potentiometer


  A variable resistor with three pins, two connected to the ends of a fixed resistor and the middle pin (wiper) moving across the resistor, dividing it into two halves
• Pushbuttons


  Momentary switches that close a circuit when pressed, good for detecting on/off signals
• Photoresistor


  A variable resistor that changes its resistance based on the amount of light that falls on its face
• 4x4 Keyboard


  Allows keystrokes to be sent to an attached computer through their micro's native USB port
• Arduino programming language

  Derived from the C programming language, with a basic structure running in at least two required parts or functions: setup() and loop()
• setup()


  The function called once when the program starts, used to initialize pin modes or begin serial communication
• loop()


  The function that loops consecutively the instructions provided, allowing the program to change, respond, and control the Arduino board
• Functions


  Blocks of code with a name and a block of statements that are executed when the function is called
• Curly braces {}


  Define the beginning and end of function blocks and statement blocks, must be balanced with an opening and closing brace
• Semicolon ;


  Used to end a statement and separate elements of the program
• Block comments /*...*/


  Areas of text ignored by the program, used for large text descriptions or comments to help understand the code
• Line comments //


  Single line comments that are ignored by the program
• Variables


  A way of naming and storing a numerical value for later use by the program
• Variable declaration


  Defining the value type, setting a name, and optionally assigning an initial value
• Variable scope


  Where a variable can be declared and used, either globally before setup() or locally within functions/statement blocks