South Jersey Robotics Club September 2014 Meeting Presentation Topic –Raspberry Pi

Agenda New Member Introductions! Show and Tell Maker Fare trip planning Raspberry Pi for starters Next meeting planning… Lunch!

Introductions Please state your: Name Interests in this area Software? Electronics? Mechanical? Which platforms (Arduino, Pic, NXT, Vex, RasPi, etc.) Level of experience What you want to get out of the club Quick description of any projects you’re currently working on or want to start

Show and Tell Anybody have anything interesting??? DragonCon in Atlanta – Robot Battles! http://youtu.be/bTtYZL9fz0M http://nearchaos.net/?p=100 1lb: https://www.youtube.com/playlist?list=PLa4DDbMiSUTVk4-LnEKkRStOquhV_aKfy 3lb: https://www.youtube.com/playlist?list=PLa4DDbMiSUTUOZ-jyBz0lxDhLEkB1JNTs 12lb: https://www.youtube.com/playlist?list=PLa4DDbMiSUTVPcliDW8jOaJE6k-5rfPvU 30lb: https://www.youtube.com/playlist?list=PLa4DDbMiSUTXQ2txAci9KSEUpvUufUCiU

NYC World Maker Fair 2014 September 20+21 Do we want to do a group ride? I can take 5 more in my car… Leave around 7am, back that evening. Which day do we want (Sat or Sun?) Buy your tickets in advance! http://makerfaire.com/# Get the Maker Faire app for your smartphone to see the exhibitors and schedule (Not listed yet) Bring money, snacks, water/drinks… Food lines were LONG last year.

Raspberry Pi What is it? What are it’s origins? What can you do with it? How do you work with it? How can you learn more…

The origins… 2006 - Humble beginnings – Desire to make a small computer, similar to what existed in the 8-bit days. Direct access to the hardware. Low cost, easy to learn with

2008… By 2008, cell phone processor technology had come along. First smartphones making a big splash. Eben Upton was working on his MBA @ Cambridge in the UK and was also working @ Broadcom. Founded the Raspberry Pi Foundation. He, his wife and co-workers + friends begin serious effort to make a $25-$35 computer. Point was to make a computer small and inexpensive enough that every kid could buy one with their allowance. Simple enough that they could learn programming with it. Powerful enough that it could do serious graphics/games. Bring back the joy and simplicity from the 8-bit days Desire to get kids programming and creating instead of just consuming again. For $1000 could outfit an entire classroom. (+ displays).

Feb 2012… Initial production run of 10,000 units made. Foundation wasn’t sure if they’d ever sell 10,000. Within 60 seconds of the web sites going live (Premier Farnell, RS Electronics), both crash under the onslaught of orders. (RS took over 100,000 pre orders on day one!) Both sites’ operators were utterly shocked at demand (claims of seeing more traffic in 24 hours than they typically see in 6 months!)

Model Progression Initially only Model B available – 256MB RAM, 2 USB ports, Ethernet. Fall of 2012, Model A released – 256MB RAM, 1 USB port, no Ethernet. Model B upgraded to 512MB RAM. Fall 2013 – Model B 2.0 released – same specs, but some improvements in the USB ports to address some power issues, 4 mounting through-holes added to board. Summer 2014 – Model B+ introduced – changed board layout (YAY!), 4 USB ports, better power on USB and across the board. Model B discontinued. Model A in more limited production due to lower demand.

Model B+ (the current model) Broadcom BCM2835 ARM v6 700Mhz CPU w/Videocore 4 GPU (roughly a Pentium 2 from around 2000) 512MB RAM (shared) 4 USB 2.0, Ethernet, CSI + DSI 1080P HDMI, Composite, analog audio outputs. 40 GPIO pins OS on microSD card. Range of different OS’s available… Powered via microUSB 5V adaptor

OS Options… Raspbian (Raspberry Pi optimized version of Debian “Wheezy” OS) – (Most people use this…) Arch Linux Gentoo Linux Pidora (Fedora Linux) RISC OS Plan 9 OpenWRT ….

Getting started…. Image your SD card with the “Noobs” download. Put the card in the Pi and power it up. Follow the prompts to install the OS(s) you want, and configure as desired.

So what can you do with it??? It’s a Linux machine, so pretty much anything you can do in Linux! Well… a SLOW linux machine (especially for the desktop) – This is being worked on though… (Wayland Compositing through GPU) Can get better performance running OS off a USB stick or even USB hard drive (way faster than SD!) Projects like XMBC, or MAME, etc. to turn the Pi into dedicated machines Web server, Database server, home video server, 3D printer server.

Ok, but why do we care about this for Robotics? GPIO!!!!! 3.3V signaling (5V WILL burn out the board!!!!!) Similar to Arduino, but different… No RTOS, so some things are harder No A/D convertor No HW PWM But, you have a much richer set of tools at your disposal Display for data visualization, Network for transport, KB+Mouse for data entry, data storage, significantly more RAM for data processing. USB Host, so can use USB devices… MANY more options for languages to program in! C/C++, Java, PHP, Python, Perl, … Can build expansion boards that link in through the GPIO also.. Can run as a ROS node Can SSH into it (remote access)

Some interesting things… Can run a full web server on the PI, and then have users interact with pages to control the GPIO and circuits connected to it! VERY low power system - < 1W at full draw! Can run reasonable amount of time on batteries while still doing significant processing. Can overclock. Some have gone as high as 1.2 ghz (I usually set for 800 or 900 Mhz). Videocore 4 GPU is about as fast as the original Xbox. You can dictate how much RAM is given to the CPU vs GPU depending upon what you’re wanting to do.

More interesting things… RasPi Camera board – connects through CSI connector – Both normal color + IR versions. Processing for this is done through the GPU, not CPU, so much faster than say a USB webcam… Can only have 1 though… Comes with full copy of Mathematica, and Wolfram Language (can do some really interesting things) GPGPU programming capable (but not well documented yet). No OpenCL though… OpenCV is available Can be a MatLab computation target

More Sources of Information Forums @ RaspberryPi.org are fantastic! http://www.raspberrypi.org/forums/ http://www.magpi.com – free PDF magazine produced monthly about the Pi. Linux Magazines often cover the Rpi as it’s a great entry to learning Linux without having to give up your Windows PC. Where can you get one? Locally – Microcenter ~$35 Online – Adafruit.com Both have TONS of add-ons and accessories!

More… A number of competitors – Stick with the Pi !!!! Usually using newer/faster chips Better GPU, more RAM, more features LOWSY support – higher price limits market and less buyers = less community support and interest. Need to be a Linux expert to really get anywhere with most of these… Stick with the Pi !!!!

Next meeting What’s a good date? October 12? 19? (Sundays) Location? Topic? Some Ideas: Basic Electronics/ Circuits Mini Sumo IMUs + GPS Filtering (Particle / Extended Kahlman) Encoders How to use an O-Scope / Logic Analyzer How to use EagleCAD How to Solder OpenCV for beginners Intro to ROS (Robot Operating System) Maze Solving Obstacle detection and avoidance/tracking Web based robot control interface Line following / line sensors / PID control