Intro to Python with GPIO

1. Introduction to PythonIntroduction to Python
ProgrammingProgramming

2. Why Python?Why Python?
 Python is what is referred to as an object-oriented programming
language (OOP)
 Python is a general purpose programming language. That means you
can use Python to write code for a number of programming tasks.
◦ Google search engine
◦ Gaming
◦ Processing financial
transactions
◦ Data Analytics
◦ Physical Programming
 Simple
 Less Syntax
 Extensive User Community
 Interpreted

3. Interpreted?Interpreted?
Python is interpreted, which means that
python code is translated and executed by
an interpreter one statement at a time.
This means you can run commands/code
on the command prompt…
Through a command
prompt with a text file…
Using an IDE

4. What Does It Look Like?What Does It Look Like?

5. Parts of a Python ProgramParts of a Python Program
Def: Source Code is the program text
entered into an interpreter by the
programmer.
◦ The saved file is referred to as, the source file.
◦ The main file in a python program, called main
◦ Can program on the command prompt
The extension to a python source file is “.py”
◦ Xcel - .xls
◦ Power Point - .ppt
Two main parts to a source file
◦ Modules
◦ Main code

6. Good Programming ProclamationsGood Programming Proclamations
Using comments to denote programs or
sections of code
◦ A comment beginning with # is called a single-line comment
because it terminates at the end of the current line.
◦ You also may use a multi-line comment—possibly containing
many lines—begins with ’’’ and ends with ’’’.
You use blank lines, space characters and tab characters
(i.e., “tabs”) to make programs easier to read.
◦ Together, these characters are known as white space.
◦ White-space characters are USUALLY ignored by the interpreter.
◦ Python has its own rules with white space

7. ModulesModules
 A module is a python source file that has prewritten
python code.
 These predefined files allow users to utilize code that has
been previously developed.
◦ Don’t have to recreate the wheel, just use the wheel and
improve on the technology.
 math
 time
 gpiozero
 os
 Code: Importing modules
 import module_name
 from module_name import class_name

8. ExpressionsExpressions
• A programming expression is a
combination of symbols to represent a
value.
• One side of an equation
• Ex.
• 5+7
• False
• print()
• led.on()

9. Printing a Line of TextPrinting a Line of Text
print(“ “)
Anything placed inside the quotes will be printed on the screen
upon execution of the print command.

10. Manipulating TimeManipulating Time
The time module is a popular module which
provides functions for working with times and
converting between them.
◦ sleep
◦ local time
◦ epoch time
Code:
◦ Importing time module
 import time
◦ Using time functions
 time.sleep(#)
 time.localtime(time.time())

11. Manipulating LED’sManipulating LED’s
 The Raspberry Pi comes with a library RPi.GPIO that allow
the manipulation of GPIO pins:
◦ Setup pins as inputs or outputs
◦ Read inputs, Set output levels
◦ Cleanup
 Code:
◦ Importing gpio module
 import RPi.GPIO as GPIO
 GPIO.setmode(GPIO.BCM)
◦ Setup an LED
 GPIO.setup(pin#, GPIO.OUT)
◦ Using led functions
 GPIO.output(pin#,GPIO.HIGH)
 GPIO.output(pin#,GPIO.LOW)

12. CheckpointCheckpoint
1. What is an IDE?
2. What is a comment and its importance?
3. How is white space used in
programming?
4. What are modules?
5. Name 2 modules