Programming Part 1

As a complement to creating electronic circuits, we can control how components behave using programming - creating a set of instructions for the microcontroller to implement. Although we can use both text as well as visual-based programming with Tinkercad Circuits, in our activities we will only focus on text-based programming.

Basic rules

• One instruction per line
• Each line has to end with a semicolon and, in a few cases, a curly bracket { or }
• Use vertical and horizontal spacing to make your program more legible

Basic structure of an Arduino program

// Any line that starts with two forward slashes will be ignored by the microcontroller 
// They are called comments and we'll use them to describe what we want our program to do

void setup() {
    // Instructions to configure and initialize components
}

void loop() {
    // Instructions to perform the tasks we need our circuits to do
}

All programs must have a setup and loop functions/commands written with the structure above - except the comments.

You can read more about the setup and loop functions on the Arduino reference website.

Variables and Datatypes

We need to have a way to store data when creating, receiving, and manipulating it. To do so, we use variables which are names for memory locations used to store values we use in our programs.

A variable has three important parts:

1. Name: We can use a combination of letters, numbers and special characters ( _ and $ ) without spaces

   Example: sensor reading is not a valid name. It should instead be sensorReading or sensor_reading
   
   

2. Data type: We use to specify which type of values we'll store in the variable

   Common data types

   Datatype	Usage	Example
   byte	Integer numbers between 0 and 255	Variables for pin numbers on the Arduino
   int	Integer numbers between -32768 and 32767	Variables for readings from an analog sensor
   float	Decimal numbers between ght-aligned	A variable holding the value calculated from the reading of a temperature sensor

3. Value stored: This is the actual data we add to the variable and retrieve from it

   Examples

   // We can create a variable and immediately add a value to it
   byte ledPin = 2;
   
   // We can also first create a variable
   byte buttonPin;
   
   // And add a value to it later
   buttonPin = 3;
   
   

Note: It is a good practice to create or declare variables at the top of your program - right before the setup function