Electronic Technologies for Art II (electric boogaloo)

Intro

tells the computer to go back to the beginning when it finishes its instructions
in pbasic we do this using a label and a goto statement
'------------------------------------------------------
Main:
'do something
Goto Main

A debug statement allows the stamp to write output back to the pc
debug statements are very useful for, well, debugging
'--------------------------------------------------------------------------
Main:
debug "hello mark" ' we can write strings to the pc by enclosing them in quotation marks
debug CR ' to generate a carriage return (so our output gets a new line) we use CR with no quotes
debug DEC 1 ' to print numbers we proceed the value with DEC to tell the stamp we want a decimal number
debug "happy ", dec 99, "th", " birthday", CR ' we can print multiple things with one debug statement if we separate them with commas
Goto Main

Variables are a way of storing data in the computers memory
In basic variables must declared.
The variable declaration gives the variable a name and defines how data can be stored in it
Variable names should be descriptive
Variables in pbasic can be of size bit (0-1), nib (0-15), byte (0-255) and word (0-65535)
When declaring a variable is pbasic we write the variable name, the word var, then the size of the variable
mybit var bit
myword var word

An example program showing the use of a variable
Note what happens when we try and make a byte variable hold more than 255
'----------------------------------------------------------
mycounter var byte ' note that variables should be declared in the very beginning of the program
Main:
mycounter = mycounter + 1 'increases the value of mycounter by 1 each time
debug "mycounter = ", DEC mycounter, CR ' output the value of mycounter as a decimal to the debug window
goto Main

If statements allow the computer to make decisions based on conditions we define
If condition is true, the lines of code after the if statement are executed
If condition is false, the lines of code after the if statement are skipped

Main:
mycounter = mycounter + 1 'increases the value of mycounter by 1 each time
debug "mycounter = ", DEC mycounter, CR ' output the value of mycounter as a decimal to the debug window
if mycounter > 9 then ' checks value of mycounter
mycounter = 0 ' if above statement is true, this line is executed
endif ' if statements must be terminated so the computer knows where to start up again if condition is false
goto Main

note the pull down resistor to prevent the input pin from floating