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Raspberry Pi Overview

Credit card sized computer
Used for electronic projects
Runs on Raspberry Pi OS (a Debian-based operating system)
Has a CPU, GPU, and RAM
Used in Lab 4B-RAD Workshop

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Raspberry Pi Hardware

SD Card Slot
USB Ports
Camera Module Port
Micro HDMI
USB-C Power
Audio Jack
Ethernet Port

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Raspberry Pi GPIO Pins

28 General Purpose Input/Output Pins
4 Power Pins
8 Ground Pins

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GPIO Pin Code Setup

GPIO Libraries

GPIO.setmode(pin identification type)	Sets the GPIO mode; defines how pins are called (GPIO.BCM or GPIO.BOARD)
GPIO.setup(port/pin, GPIO.OUT or GPIO.IN)	Sets the specific GPIO pin for output or input
GPIO.output(port/pin, 1/HIGH/True or 0/LOW/False)	Sets an output pin to a specific state
GPIO.input(port/pin)	Reads the data from an input pin

GPIO Commands

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Python

Text-based programming language
Specific Syntax

No closing mark needed after each line
Indentations for loops must be made

Comments

Line comments – begin with #
Block comments – begin and end with ’’’

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Loops

While loops

Executed so long as the condition is true

For loops

Iterates over a set sequence

Break statements

Used to break out of a loop at any time, regardless of the condition

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Ultrasonic Sensor

Used to detect distance between itself and the environment
Power, Trigger, Echo, Ground Pins

Trigger: transmits the ultrasonic wave
Echo: produces the ultrasonic wave

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Ultrasonic Wiring & Code

Coding:

Import the distance sensor
Define/setup the distance sensor echo & trigger pins

from gpiozero import DistanceSensor

sensor = DistanceSensor(echo=pin, trigger=pin)

sensor.distance returns distance value obtained from the sensor

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Sonic Pi

Code-based music creation & performance tool
Used to create new sounds through code

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Sonic Pi Commands

play note[i]	Plays a note
sleep	Delay function/break
live_loop: listen do	Loops the note pattern following it, must be named
use_real_time	Uses real time data as the instrument type… plz don’t ask more about it
sync “python file path”	Connects a variable to a python program

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EG Raspberry Pi Workshop

EG1003 | Presented by Prototyping

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Activity

Make your own Theremin using a Raspberry Pi!

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Activity - Coding Instructions

In Python,

Import the sleep and distance sensor modules from time and gpiozero respectively
Setup the distance sensor based on which pins were wired for echo and trigger
Make the following a loop:

Print the distance read
Have a 1 second delay using sleep

In Sonic Pi,

Create a live loop function called listen do
Base the loop with respect to real time readings
Make a note equal to the message leaving the Python program
Play the first note from the set

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