This is a talk about the raspberry pi. some of the software and small demo project using the gpio pins. th

1. Raspberry Pi
A Slice For Education
http://www.raspberrypi.org

2. Who Am I ?
My Name is Kris Findlay. Also known in the community as Azmodie.
I have been using the Open Source Linux operating system for over 10 years.
IT Manager for Animation Company
(makers of oscar nominated The Illusionist 2010)
I am also the Webmaster for The Software Society and The UK Adhesions
Society (Charity) which are both implemented, hosted and developed with open
source software. ( currently Django, apache, nginx, mysql )
Email address : azmodie@gmail.com or kris.findlay@gmail.com
Identi.ca/Twitter : azmodie
Google Plus : http://gplus.to/azmodie
LinkedIn : Kris Findlay

3. Agenda
• A Little history
• More device specifics
• What a Raspberry Pi can do for you ?
• Other Emerging Embeded Platforms
• Development Options
• Possible live/video demo.
• Questions

4. A Little history
The Raspberry Pi was created by the Raspberry Pi Foundation to
inspire a new generation of children to become programmers.
Foundation trustee Eben Upton, a lecturer at Cambridge at the time,
saw that the skillset of applicants to CS courses had been steadily
decreasing for a number of years. This is mostly due to the way that
education has been geared more towards using office applications and
less on understanding the hardware.
The Debian images available have lots of tools for both kids and adults
alike. so almost any age 4-50+ can enjoy learning about programming
and electronics.

5. More device specifics
Model A
256Mb RAM
1 x USB
no Ethernet
Model B
256Mb RAM
2 x USB
1 x Ethernet
Both models have a
700MHz Armv6 (Arm11)
Quad-Core Graphics chip
Diagram of Model B

6. What a RaspberryPi can do for you
• Xbmc @ Full 1080p HD
• Linux desktop - just add keyboard and mouse.
• Linux low powered server (fileserver etc..)
• Attach webcam and monitoring software
• Interface with electronics from
leds, solenoids,switches,mosfets etc..
• Almost anything else you can imagine

7. Other Emerging Embeded Platforms
• VIA APC is powered by a VIA WonderMedia 8750 800 MHz ARM11
processor, 512MB of DDR3 memory, and 2GB of flash storage. The
chip supports 1080p HD video playback, H.264 video encoding, and
OpenGL ES 2.0 graphics.
• Android Mk802 A10 AllWinner Mini Computer
The little computer looks like a portable storage device, but it has a
1.5 GHz Allwiner A10 processor, 512MB(1Gb spotted) of RAM, and
4GB of storage. It ships with Google Android 4.0 software
• Beagle Board (1GHZ ARM 7) and Beagle bone (720MHz ARM 7)
also PandaBoard (all ~$80-$180)

8. Development Options
• Python (Quick2wire),C(WiringPi), Bash, Basic, etc..
• Scratch
Geared to students and non-developers
• Various Other Linux environments including
Aros (Linux based port), Arch, Debian, Gentoo etc..
• Many open-source libraries being ported to arm.
• Cross-compiler tool-chains available.
(both soft and hard float)

9. Scratch
The MIT program Scratch is designed to provide an accessible way for
kids to learn about coding.
The program's interface makes it easy to build and change software by
dragging and dropping commands and changing variable values
through simple menus.
The version installed on the Pi comes loaded with a simple car-racing
game. Users can add and remove commands from the game, then
press play and immediately see the effect of those changes - for
instance, tweaking how cars handle or adjusting the animation for car
crashes.

10. Scratch Example

11. Quick2Wire (Python GPIO)
quick2wire have released a python api to safely access the gpio pins
from user land. eg. anyone in the gpio group. as well as allowing clean
import and export of pins.
Here’s the code that drives an LED:
from quick2wire.gpio import Pin
from time import sleep
out_pin = Pin(12, Pin.Out)
for i in range(0, 10):
out_pin.value = 1
sleep(1)
out_pin.value = 0
sleep(1)
out_pin.unexport()
http://quick2wire.com/
https://github.com/quick2wire/quick2wire-python-api
https://github.com/quick2wire/quick2wire-gpio-admin

12. My Raspberry Pi Demo
My demo focuses on input and output from python script through the gpio pins to
some simple electronics components.
This simple demo takes input from a switch
which illuminates a red led to confirm it was
pressed.
using the quick2wire api for python.
when the switch is pressed a counter is
increased by 1 until it reaches 16 at which
point it will reset counter to 0.
the corospoding value of counter at any one
time is then convirted to binary value and
displayed on the 4 green and yellow leds.
eg. counter = 3 bin outpit = 0011 led pin = 0011

13. My Raspberry Pi Demo

14. My Raspberry Pi Demo
#!/usr/bin/python3
import time # outputs binary reprisentation to 4 leds
import string # that matches count.
from quick2wire.gpio import Pin binvalue = bin(i)[2:].zfill(4)
out_pin4.value = binvalue[-1]
# import pins for output out_pin3.value = binvalue[-2]
out_pin1 = Pin(11, Pin.Out) out_pin2.value = binvalue[-3]
out_pin2 = Pin(13, Pin.Out) out_pin1.value = binvalue[-4]
out_pin3 = Pin(15, Pin.Out) time.sleep(.2)
out_pin4 = Pin(16, Pin.Out)
# trap ctrl+c to cleanly unexport pins
# import pins for input except KeyboardInterrupt:
in_pin = Pin(7, Pin.In) out_pin1.unexport()
out_pin2.unexport()
# init count out_pin3.unexport()
count = 0 out_pin4.unexport()
in_pin.unexport()
try:
while True:
# get input value of button
mybutton = in_pin.value
if mybutton == False:
count = count + 1
# reset at 16
if count == 16:
count = 0
rpi-count.py @ https://github.com/azmodie/rpi-scripts

15. expEYES Project
The expEYES (“experiments for Young Engineers and Scientists”) aims to
provide a low cost platform for experimentation and education in electronics and
physics.
The device has 12 bit Analog I/O, Digital I/O,
time interval measurements, & other features
accessible from Python. It is packaged with a
number of accessories & software which can
be used to perform a large number of
experiments.
For example, the device can be used to study
electromagnetic induction, the conductivity of
water, to measure gravity by time of flight,
alongside many other applications. It aims to
enable anybody to develop new experiments.
http://expeyes.in/articles/54/expeyes-meets-raspberry-pi

16. Links to More Details / Projects
A coffee machine controlled by Raspberry Pi
http://moccapi.blogspot.co.uk/
Solinoid based glockenspiel
http://www.thebox.myzen.co.uk/Raspberry/Buffer_Board.html
Simple Guide to the RPi GPIO Header and Pins
http://www.raspberrypi-spy.co.uk/2012/06/simple-guide-to-the-rpi-gpio-header-and-pins/
Raspberry Pi – Driving a Relay using GPIO
http://www.susa.net/wordpress/2012/06/raspberry-pi-relay-using-gpio/
Hardware Ladder Game
http://www.raspberrypi.org/archives/1488
Speach Recognition
https://sites.google.com/site/observing/Home/speech-recognition-with-the-raspberry-pi
Ideas for model railways
http://www.raspberrypi.org/phpBB3/viewtopic.php?f=37&t=5993

17. Contact Details & Any Questions ?
Email address : azmodie@gmail.com / kris.findlay@gmail.com
Twitter : azmodie
Facebook : azmodie
LinkedIn : Kris Findlay