1 Introduction to Coding

2 Example Codes A lot of example codes are given with Arduino IDE A code can often be based on a previous example rather than being created from scratch

3 Blink A simple code used to blink an LED plugged into pin 13 The following slides will go through the ‘blink’ code in detail, line by line

4 Comments The first lines of code are displayed in gray This indicates that they are comments for humans to read and not part of the actual code

5 Comments There are 2 ways to incorporate a comment into a code // ….. - Single line comment /* ….. */ - Multiline comment

6 Variables The next line of code introduces a variable called ‘led’ and sets it equal to 13 The name of the variable is chosen by the programmer In this case ‘ x = 13 ’ or ‘ table = 13’ would all suffice It is common to choose a variable name that correlates to what it is being used for In this case 13 will represent the pin the LED is plugged into

7 Variables The word ‘int’ preceding the variable name is used to tell the Arduino what we plan on storing in the variable ‘led’ ‘int’ type can store any integer between ±32,768. It cannot store a fraction or decimal ‘long’ type has a range of ± 2,147,483,648. However, it uses up more memory ‘float’ type has a range of ± E+38. It can contain decimals

8 Routines Each Arduino program is called a SKETCH and has two required functions, called ROUTINES. One is the ‘setup’ and one is the ‘loop’ Each routine contains all of its coding within curly braces void setup ( ) { } - runs once when the program begins void loop ( ) { } - runs repeatedly forever

9 pinMode In this routine there is only one line of code, ‘ pinMode ’ Each digital pin, 0 – 13, needs to be declared as either INPUT or OUTPUT An Input is constantly waiting to absorb voltage while an OUTPUT is waiting to be told to supply it outward In this case pin 13, with an LED, is an Output. We use the ‘led’ in place of ‘13’ since we already declared led = 13 ;

10 digitalWrite The next piece of code is the ‘void loop’ routine of the sketch An output pin can be set HIGH (5v ON) or LOW (0v OFF) using the digitalWrite command We declared led = 13 so we can write ‘led’ as the pin # HIGH means to turn on the pin, or send out 5V through pin 13

11 delay The ‘ delay ’ function causes the Arduino to pause delay is measured in milliseconds, so 1000 = 1 second In this ‘loop’ the first line turns on a LED plugged into pin 13, and the second line tells the controller to wait for 1 second

12 Run To compile your sketch, click the checkmark. Make sure your Arduino is plugged into an available USB port. Click the arrow to download the program to Arduino. If everything is attached correctly. The LED should blink.