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The Raspberry Pi is an ultra-low-cost credit-card sized Linux computer. I.e., $35 buys you a small device with 2 USB ports, ethernet, HDMI, and analog video and audio out. The device has 512MByte SDRAM on board and comes equipped with an SDCard slot for 'external storage'. There are several Linux Distributions available for the RasPi and what you can build with it, seems almost limitless. The Raspberry Pi, a general purpose computer, a headless server, an embedded system: Creating a Raspbian (optimized version of Debian) SDCard to boot from, containing LXDE, Midori, etc. Cutting the cord, using a small WiFi USB-dongle with the Raspberry Pi TightVNC - Providing a GUI even when running the Raspi as an headless server Using the Raspberry Pi as an IP Web Cam Server What's happening at boot and how would a tiny "Hello Word" distribution look like Using a RS-232 Serial connection to talk to the Raspberry Pi Using the Raspberry Pi as an truely embedded system. Hacking with SPI, light sensors, LEDs etc.
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Raspberry Pi.. what we have learned so far ..
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
http://wolfpaulus.com
General Purpose Computer
Headless Server
Embedded System
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Model B
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
“From a position in the mid-1990, when 17-year-olds came to the University with a grounding in several computer languages, hardware hacking, and often even with assembly language, we gradually found ourselves in a position where, by 2005, these kids were arriving having done some HTML - with a bit of PHP and Cascading Style Sheets if you were lucky.”
Why ?
RaspberryPiPrototype Model A
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
May 2011 Video of the Raspberry Pi, recorded by tech journalist Rory Cellan-Jones with his phone, goes viral.
Feb 29th 2012Google shows more searches for “Raspberry Pi” than “Lady Gaga” andhardware suppliers’ Websites crash under the load of up to 7 orders per second.
June 2012 Raspberry Pi User Forum has 20K members who have written more than 100K posts.
Feb 2013 One Million Raspberry Pi sold
H!tory
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Model B
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Model A
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
• AROS
• Android 4.0 (Ice Cream Sandwich)
• Arch Linux ARM
• Debian Squeeze
• FreeBSD
• Firefox OS
• Gentoo Linux
• Google Chrome OS
• NetBSD
• Raspberry Pi Fedora Remix
• Open webOS
• Raspbian (Debian Wheezy port with faster floating point support)
• RISC OS
• Slackware ARM
• QtonPi (Linux distribution based on the Qt framework)
Operating Sy"ems
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Creating a bootable SDCardMac OS X System Information Tool
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Download the compressed image file from http://www.raspberrypi.org/downloads
Un-compress the archive, to get to the image file.
df -h, to determine which drive is used for the SDCard
$ sudo diskutil unmount /dev/disk2s1$ sudo dd bs=1m if=./2012-09-18-wheezy-raspbian.img of=/dev/rdisk2$ sync$ sudo diskutil eject /dev/rdisk2
Creating a bootable SDCard
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Configu#ngRa$berry Pi
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
DemoCopyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Configu#ngRa$berry Pi
• sudo raspi-config
• Expand the disk image from 2GB all the way ...
• Re-boot
• sudo raspi-config
• Configure Local
• Configure Keyboard Layout
• Configure TimeZone
• Change Password
• Enable SSH
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Ra$berryPi LXDE
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Ra$berryPi
$ cat /etc/network/interfaces
auto loiface lo inet loopbackiface eth0 inet dhcp
allow-hotplug wlan0iface wlan0 inet manualwpa-roam /etc/wpa_supplicant/wpa_supplicant.confiface default inet dhcp
$ sudo nano /etc/wpa_supplicant/wpa_supplicant.conf..network={
ssid=”SSID”psk=”******“proto=RSNkey_mgmt=WPA-PSKpairwise=CCMPauth_alg=OPEN
}
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Ho"name“raspberrypi”
Change Hostname:
sudo nano /etc/hostname
sudo nano /etc/hosts
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Ra$berry PiHeadless Server
Pt.2Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Steps to make a Raspberry Pi Supercomputerhttp://www.southampton.ac.uk/~sjc/raspberrypi/pi_supercomputer_southampton_web.pdf
MPI: A High Performance Message Passing Libraryhttp://www.open-mpi.org/
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
apt-get update - updates current list of available packagesapt-get upgrade - updates currently installed packagesapt-get install package-name - installs or upgrades package-name
apt-cache search name - searches the package list for nameapt-get remove package-name - removes packageapt-get --purge remove package-name - removes package and configuration filesapt get autoclean - removes files, needed during upgrade process apt-get autoremove - removes not longer needed dependencies
Advanced Packaging Tool (APT)
Ra$berryPi APT
Sources to retrieve packages from:/etc/apt/sources.list
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Install: sudo apt-get install tightvncserverStart: tightvncserverStop: tightvncserver -kill :1
Ra$berryPi VNC Server
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
DemoCopyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Ra$berry PiCamera Server
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Ra$berry PiCamera Server
1.) Get the mpeg-streamer source code:svn co https://mjpg-streamer.svn.sourceforge.net/svnroot/mjpg-streamer mjpg-streamer
2.) Installing build dependencies sudo apt-get install libjpeg8-dev imagemagick
3.) make4.) Starting the Camera Stream./mjpg_streamer -i "./input_uvc.so" -o "./output_http.so -w ./www"
<p align="center"> <img src="http://<IP>:8080/?action=stream" width="1280" height="960" /></p>
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
DemoCopyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Ra$berry PiEmbedded Sy"em
Pt.3Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Arduino UNO : Arduino MEGA : Raspberry Pi
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
UNO MEGA DUE Pi
Operating Voltage
SRAM
FLASH-Memory
Clock Speed
USB Host
Network
Audio / Video
Current I/O pins
Digital I/O Pins
Analog Input Pins
Price
5 V 5 V 3.3 V 3.3 V
2 KB 8 KB 96 KB 512 MB
32 KB 256 KB 512 KB up to 64 MB
16 MHz 16 MHz 84 MHz 700 MHz
n/a n/a 1 2
n/a n/a n/a 10/100 wired Ethernet RJ45
n/a n/a n/aHDMI, Composite Video,
TRS-audio jack
40 mA 40 mA total 130 mA 2 to 16 mA
14 (6 PWM) 54 (15 PWM) 54 (12 PWM) 17 (1 PWM)
6 1612
2DAC Analog Out 0
$30 $59 $50 $35
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
MCP3008 8-Channel 10-Bit ADC With SPI Interface
Ra$berryPi wi& ADC
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
I2C
SPI
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
I2C connects the same two signal lines to all slaves. I.e. addressing is required and all devices need a unique addressSDA - Serial DataSCL - Serial Clock
Ra$berryPi Inter-IC Bus - I2C
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
SPI requires four signals: clock (SCLK)master output/slave input (MOSI)master input/slave output (MISO)slave select (SS) or (CS) chip-select
Ra$berryPi Se#al Pe#pheral Interface Bus - SPI
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
pi@raspberrypi ~ $ cat /etc/modprobe.d/raspi-blacklist.conf# blacklist spi and i2c by default (many users don't need them)blacklist spi-bcm2708blacklist i2c-bcm2708
Loading Kernel Modules:- Edit the raspi-blacklist.conf, so that the i2c module gets enabled.- Add the following lines to /etc/modules
i2c-dev i2c-bcm2708
Reboot, and confirm ls /dev/i2c* shows
/dev/i2c-0 /dev/i2c-1
Installing Dependencies:sudo apt-get install python-smbus i2c-tools
With i2c devices connected, run somthing like this, to discover devices addresses.sudo i2cdetect -y 0
I2C
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
pi@raspberrypi ~ $ cat /etc/modprobe.d/raspi-blacklist.conf# blacklist spi and i2c by default (many users don't need them)blacklist spi-bcm2708blacklist i2c-bcm2708
Loading Kernel Modules:Edit the raspi-blacklist.conf, so that the spi module gets loaded, Reboot, and confirm with lsmod that ‘spidev’ and ‘spi_bcm2708’ are now loaded and ls /dev/spi* shows two spi devices: /dev/spidev0.0 and /dev/spidev0.1
Installing Dependencies:sudo apt-get install python-dev git-core
Install Python bindings for Linux SPI access through spidev:cd ~git clone git://github.com/doceme/py-spidevcd py-spidev/sudo python setup.py install
... which creates /usr/local/lib/python2.7/dist-packages/spidev.so
SPI
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
IN =[0000 0001][1CNL ----][---- ----]
(8+channel) <<4OUT=[---- ----][---- -XXX][XXXX XXXX] (10bit)
((r[1] & 3) << 8) + r[2] Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
IN =[0000 0001][1CNL ----][---- ----]
(8+channel) <<4OUT=[---- ----][---- -XXX][XXXX XXXX]
r[0] ((r[1] & 3) << 8) + r[2]
r = spi.xfer2( [1, (8+chnnl)<<4, 0] ) return ((r[1] & 3) << 8) + r[2]
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
1 #!/usr/bin/python 2 import spidev 3 import time 4 5 # Performs SPI transaction, CS will be held active between blocks 6 # Generally, SPI transfer can transport up to 8KBytes 7 def readadc(chnnl): 8 if (chnnl > 7) or (chnnl < 0): 9 return -1 10 r = spi.xfer2( [1, (8+chnnl)<<4, 0] ) 11 return ((r[1] & 3) << 8) + r[2] 12 13 # Sends a String to an 7-Segment LED display, connected via SPI 14 # The maximum speed of the SPI clock input is 250kHz. 15 # SPI mode 0 (CPOL = 0, CPHA = 0); 16 # the clock line should idle low, and data is sampled on the rising edge of the clock. 17 def sendDisplay(s) : 18 spi.xfer2([118]) # clear screen 19 ca = list(s) # convert the string into a char array 20 spi.xfer2([ord(ca[0]),ord(ca[1]),ord(ca[2]),ord(ca[3])]) 21 return 22 23 # Simple moving average of the list. Up to length item are included. 24 # The new value is added to the given list while the 1st value might be removed. 25 def movavg(list, length, value): 26 list.append(value) 27 if length < len(list) : 28 del list[0] 29 sum=0 30 for x in list[:] : 31 sum+=x 32 return sum / len(list)
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
33 34 # Declare Global Variables 35 # 36 spi = spidev.SpiDev() 37 pause = 0.5 38 adc_channel = 0 39 movavg_window = 3 40 l = list() 41 42 # Main Loop 43 # 44 while True: 45 time.sleep(pause) 46 47 spi.open(0,0) # Connects the spi object to /dev/spidev-0.0 48 value = readadc(adc_channel) # Read the current ADC Channel value 49 spi.close() # Done with this SPI channel for now 50 51 ma = movavg(l, movavg_window, value) 52 sa = '%04d' % ma 53 54 print value # Show current sensor value in console 55 56 spi.open(0,1) # Connects the SPI object to /dev/spidev-0.1 57 spi.mode=0 # SPI mode 0 (CPOL = 0, CPHA = 0); 58 spi.max_speed_hz = 250000 # Set SPI clock speed to 250kHz. 59 sendDisplay(sa) # update the display 60 spi.close() # Done with this SPI channel for now
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
3.3V
Ground SPI
Light Sensor
LED-Display
ADCSPI
CS
CS
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Light Sensor
LED-Display
SPI
CSCS
SPIADC
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
DemoCopyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Se#al AccessRa$berry Pi
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
USB to TTL Serial Cable
$10
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
USB to Serial$ 20
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
FTDI Basic Breakout - 3.3V
$ 15
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
DemoCopyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
BootingRa$berry Pi
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
60MB Boot Partition easily accessible from your PC
rootfs and tmpfs
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
Summary.. what we have learned so far ..
General Purpose Computer
Headless Server
Embedded System
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
(anks for coming
Copyright © 2012-2013, Wolf Paulus. A Tech Casita Production. All rights reserved.
http://wolfpaulus.com