Raspberry Pi

Talk for South Dakota Code Camp 2012 about the Raspberry Pi and Embedded Development.

Transcript

1. http://www.raspberrypi.org/
2. Raspberry Pi (it’s an embedded device and it can run Linux) http://www.raspberrypi.org/
3. Idea • Low Cost • Low Barrier to Entry – TV – USB Keyboard – USB Mouse • Educational • and still General Purpose! http://www.raspberrypi.org/
4. Initial Setup of Raspbian • Write image to 2GB (or larger) SD card – Some issues with 32GB class 10 cards (mine did not work) • Boot! – HDMI, keyboard, USB power connected at a minimum – Optionally a TTL level UART • Initial Setup demo – Minor cheating (Static IP, setup via SSH) http://www.raspberrypi.org/
5. Hardware • BCM2835 System on Chip • Composite Video • HDMI • 1/8 ” Stereo Jack • USB Micro-B for Power – Possible to power from USB port on newer TVs http://www.raspberrypi.org/
6. Hardware Variety • Model A ($25) – 256 MB RAM – USB (1 port) • Model B ($35) – 512 MB RAM (Oct. 15) – USB Hub (2 ports) – USB Ethernet http://www.raspberrypi.org/
7. Interesting Hardware Details • BCM2835 – Broadcom System on Chip • ARM1176JZF-S CPU (with Vector Floating Point Core) • Many built-in peripherals ... – Package-on-Package assembly for DDR3 • Low Profile DDR3 http://www.raspberrypi.org/
8. BCM2835 Peripherals • Mostly on 2x13 Pin Strip Header – GPIO (General Purpose Input / Output) – UART (Serial Port, for console access, TTL levels) • Kernel Boot Messages – PWM (Pulse Width Modulation) – SPI (Serial Peripheral Interface) • Shared bus with all slave peripherals – I2C (Inter-Integrated Circuit or Two-Wire Interface) • Point to Point • Simple Interface – SCL (serial clock) – SDA (serial data) http://www.raspberrypi.org/
9. GPIO • Very easy to control “something” • Web Application to control is available! – http://code.google.com/p/webiopi/ • webiopi / LED demo http://www.raspberrypi.org/
10. I2C • Very common for simple sensors – For example, the LM75 Temperature Sensor • Not quite out of the box ... – Comment out “blacklist i2c-bcm2708” in /etc/modprobe.d/raspi-blacklist.conf – modprobe i2c-bcm2708 – modprobe i2c-dev • LM75 demo http://www.raspberrypi.org/
11. Enough Power to ... • Play 1080p Video – BCM2835 GPU includes H.264 decoder – Can license MPEG2 decoder • $3.82 – Can license VC-1 (Microsoft’s codec) • $1.91 – Audio decoded on ARM CPU • omxplayer demo – https://github.com/huceke/omxplayer – Prototype “OpenMAX” GPU API for XBMC Project – Built on top of FFmpeg http://www.raspberrypi.org/
12. Enough Power to ... • Browse the Web – Dillo 1.5 seconds – NetSurf 5.2 seconds – Midori (WebKit-based) 6.8 seconds – Chromium (Google’s Chrome browser) 9.6 seconds – IceWeasel (Debian’s build of Firefox) 16 seconds • “Sorry,” no Adobe Flash support http://www.raspberrypi.org/
13. Enough Power to ... • Run LibreOffice – writer 18 seconds – calc 16 seconds – impress 17 seconds http://www.raspberrypi.org/
14. Educational • Learn to program – gcc – python • IDLE (python IDE) – Can install other things using apt • Learn about hardware – Easy access to GPIO, SPI, and I2C http://www.raspberrypi.org/
15. More Advanced Linux Usage • Create your own “distribution” – Buildroot • http://buildroot.uclibc.org/ • https://github.com/nezticle/RaspberryPi-BuildRoot – OpenEmbedded • http://www.openembedded.org/ • https://github.com/djwillis/meta-raspberrypi http://www.raspberrypi.org/
16. More Advanced Linux Usage • Cross Compile C/C++ Code – Develop on another machine – Deploy binaries to the Raspberry Pi • ... or simply mount and run over the network – Build your own cross compiler • crosstool-ng • By hand (this isn’t much fun, but very educational) – Download a cross compiler • CodeSourcery (now from Mentor Graphics) – Debian multiarch magic! • Independent study! http://www.raspberrypi.org/
17. Disk Space • Initial Raspbian has ~350MB free space • Beneficial to use a larger card and expand the filesystem • Demo 16GB SD card has ~2.8GB used http://www.raspberrypi.org/
18. fin Dan Christensen opello@opello.org http://www.raspberrypi.org/