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TheMagPi Issue 26

1. Autotune PID for temperature PID parameters Temperature 65 C Recipes Choose recipe and select action Recipe Pilsener Stop recipe ip ownload recipe xrnl Status Actual recipe Pilsener Actual temperature 20 00 C SetPoint 60 00 C Actual power 100 Brewing step Einmaischen Remaining time for step Waiting for Setpoint 2b vm mw 9 GOOCOOS Continue Building a MashBerry To build a MashBerry you need the following parts Raspberry Pi and SD card Power supply with 5V and 12V e Housing e 2x BC547B transistor e 2x 150R resistor e 2x 100K resistor e 3x 1K5 resistor e DS18B20 temperature sensor e 12V Piezo beeper e 26 pin header for Raspberry Pi connector e Solid state relay suitable for your power needs Optional e TSOP31236 IR receiver e 3 TFT Display Reference Helpful information on the beer brewing process can be found at http www brewwiki com Brewing is the production of beer through the fermentation of extracts from malted grains traditionally barley or wheat Malted grains are made by allowing grains to germinate and then drying them in kilns The malting process develops enzymes necessary for converting complex starches into sugars Mashing is a step in the brewing process that combines crushed malts with hot water in a mash tun to convert complex starches into simple sugars that are more readily fermented The
2. COM EAR we e 8 K 4 wR9 a J4 JT NU R13 u 296 4 R45 Raspberry Pi Model B Vi 2 4 F S Raspberry Pi 2014 ETE P J sal cH ue S22 2 1d gi A ZERERRERERREE E DISPLAY R58 A 7 As AE ae Ns A N Geeta Pak Og v SEM 17 aie ae E f B E p d eso ue BY NC SA b Bs i x M Y f arry piis amari of Tria masona it e oTe ag i This havi crastar Using s na Derry Pi futer http w UE DI com Welcome to Issue 26 of The MagPi magazine This month s MagPi contains another great selection of hardware software and programming articles Michael Giles explains how to turn your Raspberry Pi into a magic wand with a fun hardware project that demonstrates the persistence of vision effect while John Mahorney from Suncoast Science Center in Florida shows how a Raspberry Pi is used to display dynamic art Big news this month is the launch of the Model B and MagPi writer Aaron Shaw has all the details for you on page 22 Robotics is always a popular theme and Harry Gee continues on from last month s article and shows how to add speech voice control and facial recognition to your robot Additionally Rishi Deshpande describes how to use the SmartDrive controller board to easily control high current motors Another popular topic is beer and Sebastian Duell explains his hardware and software Mashberry project which he uses to optimise the mashing proce
3. Multiple images of the same face should be taken from different angles We use these images to train the face recognition model This will take some minutes to finish Enter python train py After this part we will have to adjust the config py script in order to configure our servo motors movement The various options are detailed in the above link and will vary depending on your application The final Python script that we need initialises the Raspberry Pi camera and performs the facial recognition This version of the code is adapted from the box py script from Tony Dicola s OpenCV Facial Recognition project on GitHub httos github com tdicola pi facerec box This script detects a single face and is the code we need to run our Raspberry Pi in face recognition mode __author__ alexgray adapted from original code by Tony Dicola FuLL source https github com tdicola p1 facerec box import cv2 import config import face def init camera camera config get camera return camera def face detect camera Get image from camera image camera read Convert image to grayscale image cv2 cvtColor image cv2 COLOR_RGB2GRAY Get coordinates of single face in captured image Coords will mean a face was detected result face detect_singleCimage If no face return False else True if result is None return False else return True def main Initialise the camera camera ini
4. 0 amp amp count lt 360 draw 1fCcount gt 465 var ccedocument getElLlementById canvas1 getContext 2d cc restore cc clearRect 0 0 canvasWidth canvasHeight initialize count 0 function draw 1 var ccedocument getElementByIdC canvas1 getContext 2d fiberHue hue Math sin Math random Math PI 2 dhue fiberColor hsla fiberHue 100 50 1 cc rotate Math random Math PI 2 for var j 0 J lt 200 j X x Math random 2 y y Math sin Math random Math PI 2 tension cc fillStyle fiberColor cc fillRect x y 2 1 X y 0 0 lt script gt lt head gt lt body onload initial1izeC style margin Opx border px padding Q px background color 000000 overflow hidden gt canvas id canvas1 width 800 height 600 gt lt body gt lt html gt omm PiLight Light for RPi Camera Infrared and Regular as SmartUPS pa power supply for Raspberry Pi 6 Channel Servo Controller for Raspberry Pi DAVVN 3 ROBOTICS X More robot kits and parts at wwwW dawnrobotics co uk powered Raspberry Pi Camera Robot Kit Drive over WiFi using a Tablet Smartphone or PC Programmable using Python and Find lots of robot OpenCV for Computer Vision and Raspberry Pi tutorials at All software Open Source blog dawn robotics co uk SMARTDRIVE ROBOT Us
5. 16th August 2014 1 30pm to 4 30pm PDT Where Computer History Museum 1401 N Shoreline Blvd Mountain View CA 94043 USA Open to all and free to attend whether you are new or experienced with the Raspberry Pi http www eventbrite com e 8469381 147 Malvern Raspberry Jam When Wednesday 20th August 2014 3 45pm to 5 00pm Student and 7 30pm to 9 00pm Adult Where Wyche Innovation Centre Walwyn Road Upper Colwall Malvern WR13 6PL UK Come to be inspired make friends and collaborate on new ideas Student Jam http www eventbrite com e 10077559251 Adult Jam http www eventbrite com e 1 1053058997 Manchester Raspberry Jam 22 When Saturday 30th August 2014 10 00am to 5 00pm Where The Shed John Dalton West Chester Street Manchester M1 5GD UK Everyone welcome Opening talk around 10am followed by hacking on whatever you want http mcrraspjam org uk next event and http www eventbrite co uk e 1 245888385 7 Soton Winchester and Basingstoke Raspberry Pi Meeting When Wednesday 3rd September 2014 8 00pm to 10 00pm Where The Roebuck PH Stockbridge Road Winchester SO23 7BZ UK Helaxed evening Q amp A event over a beer with Raspberry Pi s running no need to register Contact 34 Dougie Lawson dl1ims gmail com RasPiCo a DN li Il di t ee See dau ee bim oon oo Connect your TEES Pi to ue World build four Dwn Contol Panel New Live Controls gt
6. Build your pages on your iPad iPhone gt EASY to setup no syncing required gt Ten pages of control panels gt Exchange your panels with friends gt Supports any computer that supports Supports multiple Raspberry Pis and Python windows linux etc multiple Arduinos Visit milocreek com for more info MiloC eek Supports Arduino with in app purchase G9 4 Available on the AppStore Plusberry Pi Now live on IndieG amp ogo Beautiful design Integrated powered hub 2 5 HDD bay Power switch wwwW PlusberryPi com IF ufo AND uf gt rma iplotsp a ufol 0 0 Part 2 Variables procedures and gt sprites A few years ago brought my old BBC Micro down from the loft to show my kids how started in computing To my surprise my two girls Molly and Gracie and my son David were all intrigued by the BASIC prompt and the Syntax Error response returned by about every input They wanted to know more so we spent a few days learning a few BASIC programming commands and playing some classic games It got me thinking that wouldn t it be great to bring back a computer in the same vein something that brought access to programming right to the forefront just like it was back in the 1980 s The Raspberry Pi turned out to be the answer as it retains many attributes of the BBC Micro such as accessible GPIO ports The only downside was that it did not have a version of BASIC
7. Editor by pressing F1 Editor Help Pages General Fibandon edit This help i Lood progrom into interpreter Lood ond Run program Joggle Keyword colouring 20ve file Lood new file Rever o last Soave Insert file Erose edit buffer Press SPACE for next page i j in LN mm mn mn Cat g a cona 0 E F F F F F F F F F This is the basic structure of our program It is important as we progress to try and build some good habits When naming variables a popular method is called Camel Case ThislsCamelCase The reason we use it is because we are not allowed to use spaces in variable names Camel Case notice the humps makes things readable at a glance As you write larger programs another variable issue will raise its head Short non related variable names WILL cause you grief later A 200 line program will be very difficult to understand if you have used variable names like pbx instead of PlayerBulletX and just X instead of PLayerX Long names take more time when editing but they will save hours later when debugging Also consider at some point your code might be scrutinised by someone else You do want to make your program legible Time to play a game We are going to store our variables in a PROCedure called Setup along with our sprites and sound files This keeps our program organised The CYCLE and REPEAT commands define our main program loop This
8. an I C level shifter between 5V and 3V3 is needed to connect it to the Raspberry Pi As an alternative a D81820 sensor can be used There are sensors with the appropriate metal housing and temperature range gt 100 C available These sensors can be connected to the Raspberry Pi using only a single resistor To control the electric heater of the mash container a solid state relay SSR is used The SSR is driven by a simple transistor circuit connected to the GPIO of the Raspberry Pi Such a circuit also drives the piezo beeper The SSR is housed in an external box including power plugs and filters For visualization a 3 TFT display is connected to the Raspberry Pi s composite video port An IR receiver can be connected to the GPIO to enable MashBerry to receive IR codes from a common IR remote control Software The MashBerry software is built using the Qt framework The heart of it is the PID controller which is used to control the temperature of the mash The PID controller uses the temperatures of the temperature sensor as an input and outputs a power value between 0 100 A PID controller is a controller with a feedback loop Each time the PID algorithm is triggered the temperature error between the set point and the actual temperature is calculated With this error the old output value and the PID parameters K Kp Kj a new output value is calculated using the three values called the proportion
9. for debugging any audio problems you have please see this great post on Raspberry Pi Spy http www raspberry pi spy co uk 201 3 06 raspberry pi command line audio To install eSpeak on the command line enter sudo apt get install espeak This will install the espeak and espeak data packages Try issuing a command straight to eSpeak espeak Hello can we be friends The first time eSpeak runs it will probably have a short delay before speaking which seems to disappear on subsequent executions You will also probably get quite a long list of warnings about ALSA lib server sockets and the jack server These are harmless and can be ignored The important thing is that it speaks to you More details of TTS and working with eSpeak can be found at http espeak sourceforge net Now that we can give a Raspberry Pi robot the power of speech what do you think it could be used for Maybe it could let you Know whenever you have new email and read it out aloud I m sure you can thinking of several other things As a simple code example let s consider our PiBots speech being triggered every time it bumps into something Here we have added a hardware switch that gets triggered everytime it bumps into anything From our PiBot Python library we have exposed this event as a function called PiBot isBumped from espeak import espeak import PiBot import random def bumpReply if PiBot isBumped responses Ouch tha
10. is where all the action will happen Now we need to load the sprites so we can start having some fun Open the Editor by pressing F2 if you re not already in it Edit the MagP1 code so it becomes m Magpi Game PROC Setup CYCLE PROC ScreenUpdate REPEAT END DEF PROC ScreenUpdate plotSprite Ship ShipX ShipY 0 UPDATE ENDPROC DEF PROC Setup HGR updateMode 0 ShipX 0 ShipY gHeight 2 Ship newSprite 1 loadSprite C Player2 bmp Ship 0 ENDPROC It should look something like this in the Editor Aes qe pm Pus h Ft m Ci eenipgate When you run the program you might be surprised to see a bright pink magenta box surrounding our space ship Don t worry there s nothing wrong we just need to set this colour to be transparent FUZE BASIC will not draw any Ee colour that is specified as the transparent colour We need this because a sprite graphic is simply a box and everything in the box is drawn So if we have a white background in our sprite it will C display a white box which is no good on our black space background We can stop this by specifying a single colour to be transparent so it is not drawn Add the setSpriteTrans command directly below the LoadSprite command as shown below and then press F3 to run the program again loadSprite Player2 bmp Ship 0 setSpriteTrans Ship 255 0 255 That s much better Program explanation Now t
11. net shadow 6 wireless controller for ps3 1 html 4 2x Pittman GM9234E765 R1 motors http www gearseds com competition_ motor html I 03 MASHBERRY Homebrewing Mash Berry Ue Homebrewing with the Raspberry Pi Introduction When you are into homebrewing you are faced with different problems Brewing equipment preferably should be low priced When doing all grain brewing there is also the need for a system that can control the temperature of the mash at different points and at different times There are professional brewing controllers available but these are very expensive So the idea was to build a cheap brewing controller mainly from standard components The controller should have a graphic display a web interface for configuration and a recipe management system to make brewing different sorts of beer easier The Raspberry Pi seemed to be ideal Brewing beer Beer is made from malt hops water and yeast To get a beer out of these ingredients several processing steps are needed These steps are in general e Mashing e Lautering Hop boiling Fermentation The first step in brewing is the mashing During this step the starch of the malt is converted to sugar and extracted from the malt so the wort is obtained Wort is the liquid extracted from the mashing process during the brewing of beer The conversion of the starch to sugar is done by the enzymes contai
12. purposes oo Feo When creating the code to actually move the robot it is helpful to create a separate function for that purpose The function is as follows def move motor speed direction 1 1fCspeed lt Q direction 0 Speed speed 1 if speed gt 100 speed 100 SmartDrive SmartDrive Run Unlimi ted motor direction speed When the direction is O the motor will run backwards and when the direction is 1 the motor will run forwards The SmartDrive speed ranges from 0 100 therefore it is important to keep within this scale This function can now be called whenever prompted When starting on the main loop of the program please note that scaling for the joystick axis is required The get axis function from pygame ranges from 1 to 1 with O being centered Therefore we need to scale by 100 to be able to use the axis values for the speed parameter in the above move function The main loop code is as follows while True pygame event get x1 100 j get axisC0 yl 100 j get_axis 1 if j get button 1 move C1 Q0 move 2 Q0 Sys exit 1 LMotor x1 y1 rMotor x1 yl move 1 lMotor move 2 rMotor The get button function is used to quit the program and stop the robot from running have listed all of the electrical parts motors and other hardware that have used for this project would also recommend checking out your local scrapyard for any motors that you would l
13. sudo apt get install x11 xserver utils Your dynamic artwork is a web page On the next page there is some example artwork code Enter this code into a text editor and save it as sample html Put this sample file into the home p1 folder When the Raspberry Pi is powered on we want to automatically start Chromium with the artwork running On the command line enter sudo nano etc xdg lxsession LXDE autostart Comment out the following lines by prefixing them with a Zelxpanel profile LXDE Zepcmanfm desktop profile LXDE xscreensaver no splash Then add the following lines xset s off xset dpms xset s noblank chromium kiosk incognito home pi sample html In nano you should see the following GNU nano 2 2 6 File etc xdg lxsession LXDE a lxpanel profile LXDE pcmantm desktop profile LXDE xset s oft Gxset dpms xset s noblank chromium kiosk incognito home pi sample htmL To save your changes press lt Ctrl gt X then Y then Enter When you restart your Raspberry Pi the sample artwork should automatically appear To open a second login press lt Ctrl gt lt Alt gt F2 To return back to the art display press lt Ctr1 gt lt ALt gt F7 Pi Canvas artwork The Suncoast Science Center has a display area for showcasing inventions of all kinds created in the Fab Lab Here is a screen shot of a Pi Canvas on display in the Fab Lab display area The artwork is t
14. that provides a consistent unified user interface and user experience across multiple devices and media types VolP is the transmission of voice over the internet using protocols such as SIP Session Initiation Protocol and RTP Real time Transport Protocol among others Baseline To implement a VolP UC solution the system must meet various industry standards plus the network equipment must be able to differentiate and prioritise voice and video applications over other types of data usage Basic Components The hardware and software requirements are simple You probably just need to download the software Hardware e Raspberry Pi Model B B e 4 GB SD card minimum e 1A power supply Network cable Optional SIP phone or SIP adapter this article uses the Dlink DPH 150SE Software e Raspbian Asterisk communications software e LinPhone soft phone supports iOS Android Blackberry Linux Windows and OSX You can download this from Installation For the initial setup you may need to use a USB keyboard and mouse with the Raspberry Pi plus a connection to a monitor Once configured the Raspberry Pi will run headless The best and easiest way to get the Asterisk software is to download the latest SD card image at This contains Raspbian with the Asterisk communication software and FreePBX GUI pre installed The image is written to the SD card following the steps at When the system starts l
15. the integral and the derivative PID The PID controller has the advantage if properly tuned to reach a nearly constant temperature The power value from the PID is then fed into a kernel driver which controls the GPIO in real time This driver is basically a hack of the system s timer interrupt where the switching of the GPIO takes place The driver does the switching from 0 100 in two seconds One percent of output power results in 20ms of on time for the SSH At 50Hz mains frequency this is one AC cycle per percent With this method the power of the heater can be controlled very accurately The PID parameters can also be autotuned More info about PID controllers can be found at http en wikipedia org wiki PID controller The MashBerry application runs on a Linux system without X11 using the embedded version of Qt4 which runs directly on the framebuffer So very little resources are used The software can be downloaded from http sebastian duell de en mashberry downloads html There is also a complete SD card image available It is based on Raspbian and includes the MashBerry application the framebuffer version of the Qt libraries and a modified Linux kernel which is capable of driving the SSR relay via the GPIO in real time settings Language English Tempsensor PT1000 MultiPlDparams No PID tuning Recipe Pilsener Autotune PID for hole recipe Overwrite existing PID parameters Temperature C
16. A on the BitScope Micro Fig 2 shows the pin layout of the BitScope Micro to help you to select the right pins 1M 10pF CHB L5 L3 L1 o O O 0 0000 L4 L2 Lo GND GND Fig 2 Pin layout of the BitScope Micro photo courtesy by BitScope Designs Press the top of the black test lead down so that the metal gripper appears at the opposite side and connect to pin 6 of the GPIO on the Raspberry Pi Do the same with the red test lead but connect it to pin 2 of the GPIO Fig 3 shows the setup Omm nuit TIT Fig 3 Measuring 5V on the GPIO pins 2 and 6 of the Raspberry Pi Look at the main screen of the BitScope DSO 1 The x axis is the line in the middle and has small vertical lines to sub divide each square This is our OV line But our yellow beam is in the middle of the third square above the x axis Because we know there is a voltage of 5V between pin 2 the plus pole and pin 6 the minus pole and we set the channel control to 2V per Div so the horizontal line indicates exactly this voltage In Fig 4 have inserted an extra scale in red on the y axis to help you interpret the screen Hit5cope DS0 2 7 BE FALL LEVEL Fig 4 Measuring 5V between the Rasperry Pi GPIO pins 2 and 6 You may get a reference measurement with your multimeter if you like Could we measure other and higher voltages than 5V Sure but what about our
17. A to enable headless communication electronics Using Asterisk to implement a low cost telephone system After investigating a number of technology solutions that provide VoIP Voice over Internet Protocol and IP telephony services including support for the new trend of UC Unified Communications for small businesses personally concluded that the Raspberry Pi is able to deliver a totally viable and very low cost solution When compared to the 100 s needed to invest in a dedicated server for a VoIP UC solution the cost of a Raspberry Pi and accessories is unmatched The Raspberry Pi solution is based on Raspbian running the Asterisk VoIP UC software This open source solution provides a high degree of configuration and of course can be used for a multitude of solutions and applications in different areas This article demonstrates that VoIP UC solutions are not high risk and do not require high implementation costs Introduction Telephony has evolved rapidly over the past few decades migrating from analogue communications to digital communications and IP telephony based on VoIP This also enables Unified Communications the integration of real time communication services such as instant messaging chat telephony data sharing video conferencing speech recognition etc with non real time communication services such as voicemail email SMS and fax UC is not necessarily a single product but a set of products
18. any readers have asked us to produce printed copies of the magazine we are pleased to announce that printed copies are now regularly available for purchase at the following Raspberry PI retailers Americas AsiaPac ORK exo t Yn 6 3 ec exce 2a Wo i Have Your Say The MagPi is produced by the Raspberry Pi community for the Raspberry Pi community Each month we aim to educate and entertain you with exciting projects for every skill level We are always looking for new ideas opinions and feedback to help us continue to produce the kind of magazine you want to read Please send your feedback to editor themagpi com or post to our Facebook page at http www facebook com MagPiMagazine or send a tweet to TheMagP1 Please send your article ideas to articles themagpi com We look forward to reading your comments
19. aspberry Pi has enough power to supply the 5V the clock generator needs Therefore connect a blue test lead from pin 6 of the Raspberry Pi GPIO Gnd to the Gnd connection of the breadboard and a green test lead from pin 2 of the Raspberry Pi GPIO 5V to the Vcc connection of the breadboard Two more test lead connections are needed Connect pin 3 of the NE555 with CHA of the BitScope Micro and connect Gnd of the breadboard with Gnd of the BitScope Micro opposite CHA Phew Things can get complicated fast Look at Fig 7 and make sure you have all the connections right gt 1111 i oam mcer ae a Oe RS Fig 7 Connecting the clock generator to the Raspberry Pi and BitScope Micro Look at the main screen of the BitScope DSO software 1 and you should see a similar square wave as shown in Fig 8 2 BitScope DSO 2 7 TRIGGERS AUTO O Ld Bo BGS o cio RR O AUTO roos LX Cc NELIN T NEN Fig 8 Output of the clock generator circuit This square wave proves that our NE555 is still functional and could be used for our next electronics project If you do not see a square wave check your circuit for any errors If all connections between the different parts and the Raspberry Pi are ok and you still don t get a square wave it can be assumed that the NE555 or one of the other components is defective If your clock generator is operational you may try to find out the frequency with which your cloc
20. atory DSCP fields 3 Edit NAT and Firewall amp Direct connection to the Internet Public IP address Behind NAT Firewall specify gateway IP D Behind NAT Firewall use STUN to resolve Stun server 9 Behind NAT Firewall use ICE of Done In the Multimedia settings verify that Echo cancellation is enabled In Manage SIP Accounts enter your display name In my example the soft phone is extension 302 so the username is 302 The resulting SIP address is lt sip 302 172 31 15 7 gt Click the Add button to register the account with Asterisk Enter your SIP identity from above and the SIP Proxy address i e the IP address of your Raspberry Pi oee the screenshot at the top of the next column for details Configure a SIP account Your SIP identity sip 3028172 31 15 7 SIF Proxy address lt sip 172 31 15 11 gt Route optional Registration duration sec 3600 Register Publish presence information EJ AX Cancel You will then be asked for a password For extension 302 set this to be ext302 Click OK and the registration should be confirmed SNetwork settings Multimedia settings amp Manage SIP Accounts Codecs j User interface Default identity Your display name eg John Doe 302 Your username 302 Your resulting SIP address 302 lt sip 302 172 31 15 8 gt lacay accounts sip 302 172 31 15 7 sip 302 172 31 15 11 Please enter your password f
21. d above with Number1 and Answer etc are set in stone If we give a variable the name NUMBER1 then we must refer to it as such every time in our program Variable names are case sensitive If we expect the variable numBER1 to return the same result then we are in for a big surprise The variable numBER1 has not been defined so will generate an error Enough of the dull stuff You should at this point be in the Editor with the program as listed on the left Press F3 If at this point the program has not been saved then it will ask you to do so Just enter a name like Hello and press Enter The program should then run Hello MagPi should display in a never ending list down the Screen To stop it press the Esc key Press F2 to go back to the Editor and change the program so that it looks like the following CYCLE PRINT Hello MagPi REPEAT The only difference is that we have added a space in between MagPi and the end quotation mark and added a semi colon to the end of the PRINT line The semi colon tells BASIC to display the next item immediately after the last one and not on a new line The space just puts a gap in between Press F3 to run the program again This time instead of a long list of Hello MagPi going down the screen this time it displays Hello MagPi across the screen More about the Editor Again press Esc to exit the program and then F12 to wipe the current program from memory You
22. directly suited to our needs Enter Gordon Henderson the author of the WiringPi libraries who developed a version of BASIC called RTB Return To BASIC If you have programmed in BBC BASIC arguably one of the best ever versions of BASIC then you will be very familiar with RTB It is designed specifically to support the Raspberry Pi and its GPIO A deal was struck between FUZE and Gordon to produce FUZE BASIC which includes a vast array of enhancements These tailor FUZE BASIC SO it is more in line with the requirements of the newly revised UK IT curriculum At FUZE we focus on FUZE BASIC to deliver a learning experience far more accessible to a broader age range and ability group than more complex languages Quite simply BASIC is easier to pick up and learn than just about any other language ever devised You do not need to be adept at maths you do not need to understand the operating system to any great extent and you certainly don t need to have programmed before While more experienced programmers might scoff at us BASIC students assure you that BASIC has something for everyone Even the most adept coders will find BASIC a great platform to test out ideas and experiment Getting FUZE BASIC am very pleased to announce that FUZE BASIC is available for FREE Visit http www fuze co uk click on Resources and then download the latest FUZE boot image from the FUZE BASIC Updates tab The FUZE boot image is the same a
23. dy prompt Let s familiarise ourselves with the environment The Ready gt prompt means you are in Direct mode Type in Hello and press Enter You will get the message Equals expected That is exactly what should happen The computer has no idea what Hello means Instead enter Number 1 Number 2 Answer Number1 Number2 l d suspect there are many of you who are already more than comfortable with what is going on here but we need to explain to the newcomers Variables The words Number1 Number2 and Answer are just names They are called variables Variables are tags we store values in We could have used any name but generally it is best to use names that make sense in the context of the program If we wrote a program using variables like N1 and N2 and A then when we come back to the program later we will have no idea what everything means However variable names like ShipX and ShipY are more obvious Try and make this a habit You will appreciate it later So we stored the number 10 in the variable Numberi and 10 in the variable Number2 We then said that the variable Answer equals Number1 Number2 At this point you should know what the value of Answer is Do you hope so or were in big trouble Enter PRINT Answer You should see 20 lf anything else whatsoever happens then something has not gone to plan and you should go back and check where you went wrong Direct mode and Edit mod
24. e We are currently in Direct mode This is where we can enter commands and expect an m 1 2 immediate response For example we can check variables and enter simple instructions It s not programming though is it Press F2 to enter the FUZE BASIC Editor Useful commands shortcuts in Direct mode EXIT Exit and return to the desktop DIR List files in the current folder CD name Change to folder name CD Go back one folder LOAD name Load program name SAVE name Save program name NEWor F12 Clear program from memory F2 Open the editor RUN or F3 Run the current program You will see a blank screen with a green flashing cursor and a dotted line across the bottom This is the Editor environment Here we can enter a list of program instructions that can be saved and executed RUN whenever we want Press F2 again This will take you back to Direct mode Actually it will ask you for a file name In this first case don t bother just press F2 again and it will put you in Direct mode again One last time press F2 again and you will be back in the Editor You get the idea F2 takes you between the Editor and Direct mode Hello MagPi In the Editor enter the following program CYCLE PRINT Hello MagPi REPEAT You don t actually need to worry about capitals or lower case when entering commands It is a good habit in FUZE BASIC to type commands in capitals but it is not essential However the names we give to variables as we di
25. e called CheckControls which will check for the Up Down Left and Right arrow keys being pressed and correspondingly change the position of the rocket First we add the call to the CheckControls procedure to our main program loop CYCLE PROC CheckControls PROC ScreenUpdate REPEAT Now add the definition of the CheckControls procedure to your program It does not matter where you place this procedure but we will place it before the definition of the ScreenUpdate procedure at DEF PROC CheckControls UpKey scanKeyboard scanUp DownKey scanKeyboard CscanDown LeftKey scanKeyboard scanLeft RightKey scanKeyboard scanRight IF UpKey THEN ShipY ShipY 1 IF DownKey THEN ShipY ShipY 1 IF LeftKey THEN ShipX ShipX 1 IF RightKey THEN ShipX ShipX 1 ENDPROC Your new code should look something like this in the Editor Run the program by pressing F3 I m going to be very disappointed if you have not worked out what will happen when you press the cursor keys Coming up Next time we will learn more BASIC commands plus add a few enemies and some fire power to our game FJUJZIEDUESUU FJUJZ EJ COMPETITION TEASER FUJZ EP ariulzit Ras BA BA i www Fuze In our October issue the folks at FUZE are planning to run a FUZE BASIC programming competition with an incredible 500 of prizes First prize is the amazing FUZE T2 R kit worth 230 Not only does this have eve
26. e interfaces 5 manpage or usr share doc ifupdown examples for more information auto Lo auto etho iface lo inet Loopback i EH ae iface eth ine static Once saved reboot to use your new network settings From now on you can use either the static IP or the raspbx hostname For example when using PuTTY to connect with the static IP address above can now use root 172 31 15 11 Asterisk configuration We are now going to use the FreePBX graphical user interface to configure the Asterisk software This helps to make the process simple and easy The FreePBX software came pre installed with the Asterisk image An example architecture diagram is shown below INTERNET OTHER NETWORKS wo s MODEM According to ISP 192 168 1 1 cae HardPhone IP 172 31 15 20 EXT 300 ce HardPhone IP 172 31 15 21 EXT 301 ROUTER 172 31 15 1 SERVER VoIP UC RASPBERRY PI MODEL B 172 31 15 11 GATEWAY 172 31 15 1 LAPTOP WITH LINPHONE SoftPhone 172 31 15 7 wired 172 31 15 8 wireless EXT 302 To start FreePBX open a web browser and enter http raspbx or your static IP For Apple Mac you will enter http raspbx Local This will open the FreePBX Administration page There are three options 1 FreePBX Administration is used to configure Asterisk 2 User Control Panel is for users to adjust their personal settings 3 Get Support opens the FreePBX website FreePBX Admi
27. e will use the Dlink DPH 150SE as an example The important settings are to disable the DHCP option verify the SIP Phone Port Number is 5060 the Registrar Server is the IP address of your Raspberry Pi and in the Others section we enable the Register with Proxy option For the SIP Account Settings option we enter the details we previously used when adding extensions using FreePBX The Authentication User Name is the extension number and the Authentication Password is the secret entry i e ext300 lommm DPH pPH 1s0sE f NN SYSTEM ADVANCE SIP WO ae SIP Account Settings SIP ACCOUNT SETTING Default Account Account 1 w Account Active O Disable Enable Display Name 300 SIP User Name 300 Authentication User Name 300 Authentication Password eseees Ring Type Default v Register Status Register Softphone configuration Start Linphone and from the Options menu choose Preferences Confirm the Network settings are as shown below g Jj FY Settings it By X Network settings Multimedia settings ff Manage SIP Accounts Codecs 7 User interface Transport J Set Maximum Transmission Unit I Send DTMFs as SIP info J Use IPv6 instead of IPv4 Network protocol and ports SIP UDP port 5060 SIP TCP port 5060 Audio RTP UDP 7078 7078 amp Fixed Video RTP UDP 9078 J 9078 gt amp Fixed Media encryption type pone xj Media encryption is mand
28. ea on the back for attaching the Raspberry Pi which allows for flush wall mounting Finally it has a narrow clean bezel which makes a nice frame Pi Canvas software Just like the hardware the Pi Canvas software requirements are simple and familiar to many Latest Raspbian OS e Chromium web browser e HTML5 Canvas element e JavaScript Chromium has a kiosk mode for full screen operation with no browser decoration or controls The HTML5 Canvas element offers good graphics capabilities for art and is fast Finally JavaScript is an easy but capable language for browsers This software combination runs very well on a Raspberry Pi Example JavaScript tutorials can be found at http www w93schools com js You should also visit http www htmldcanvastutorials com Pi Canvas configuration In addition to the normal Raspberry Pi setup the following steps are required to make a Pi Canvas with the listed hardware and software You will need separate power for the Raspberry Pi because the HDTV does not supply adequate power for this step Enter the following on the command line Sudo apt get update Sudo raspi config When the Raspberry Pi Software Configuration Tool appears enable the option to boot to desktop Next we will install the chromium package plus some other utilities The unclutter package removes the mouse cursor from the screen after some inactivity Sudo apt get install chromium sudo apt get install unclutter
29. een 2053990900999 9 0000000 246 CETTE dto Apparatus assembly In order to move the LEDs fast enough to see the image attached the Raspberry Pi along with the Pi Prototyping board to a long flat wooden stick using screws and spacers Wood was used to avoid any shorting that may occur On the back of the stick attached the SmartUPS to power the Raspberry Pi and make my device more mobile The SmartUPS is powered by three AA batteries and though it has several functions is only used for power in this project On the other end of the wooden stick drilled a hole and attached a rod to be used as a handle This allowed me to easily swing the magic wand around in a circle Installing packages For this program used the OpenElectrons LSM303 package installed using the pip package manager If you do not have pip you can get it by opening a terminal window and typing sudo easy install pip To install the OpenElectrons LSM303 package type sudo pip install OpenElectrons LSM303 This command will install the package as well as the OpenElectrons_i2c package needed for 12C functions Programming In order to generate the ASCII characters first created a look up table The table is just a dictionary in which each character is a list containing five hexadecimal values Each value generates one vertical line of pixels The example below shows the hexadecimal for the letters B C and D A full alphabet with numb
30. end of the program It is a good habit to keep all the main setup commands in one place so it is easy to find them Also this will usually end up being quite a big routine so you don t want it getting in the way at the beginning HGR This initialises high resolution graphics mode updateMode 0 Sets the screen update system to manual ShipX ShipY Q gHeight 2 ShipX and ShipY are used to store the X and Y coordinates of the player s ship ShipY takes a system constant called gHeight which is the pixel height of the screen and divides it by 2 to determine the vertical middle of the screen Ship newSprite 1 This creates a sprite ID called Ship with room for just one version of the graphic The version count starts from O Later we will increase the number of versions so we can animate the sprite loadSprite Player2 bmp Ship 0 The loadSprite command assigns the named graphic image to a sprite ID Ship and stores it as version 0 setSpriteTrans Ship 255 0 255 This specifies the transparent colour of the sprite ID Ship to bright pink using red 255 green 0 and blue 255 values between 0 and 255 ENDPROC Return back to where the procedure was called Add controls and movement We are now making progress but unfortunately we do not have space for much more this month Let s add one more piece to our game to make it feel like we are really getting somewhere We are going to add a new procedur
31. erometer PI CANVAS DIGITAL ART DISPLAY Display dynamic art using a Raspberry Pi SMARTDRIVE ROBOT Coding a remote controlled robot with the SmartDrive add on board MASHBERRY Homebrewing with the Raspberry Pi PIBOT Part 2 Add the power of speech hearing and vision to your robot RASPBERRY PI MODEL B All the details on the latest addition to the Raspberry Pi range BITSCOPE Part 2 Electronic measurement with the BitScope oscilloscope add on board VOICE OVER IP SERVER Using Asterisk to implement a low cost telephone system THIS MONTH S EVENTS GUIDE Southend UK Mountain View CA Malvern UK Manchester UK Winchester UK FUZE BASIC Part 2 Variables procedures and sprites HAVE YOUR SAY Send us your feedback and article ideas accelerometer Persistence of Vision displays create an image by quickly displaying one column of pixels at a time When the device moves rapidly along a linear path the human eye can view the image as a whole as it is built up column by column When say rapid mean rapid at least one twenty fifth of a second At this speed an afterimage is seen in the retina and the viewer perceives the rapid succession of LED blinks as a full image Operation The magic wand displays five columns of pixels for each specific letter in a user defined string The accelerometer is used to determine which direction the wand is swinging to avoid displaying the string in reverse e N lt 1
32. ers and symbols can be downloaded in the Python sample programs available from http www openelectrons com pages 63 5x7 ascii characters Lookup table lookuptable 1 B 0x7 f 0x49 0x49 0x49 0x306 C 0x3e 0x41 0x41 0x41 0x2 D 0x7f 0x41 0x41 0x41 0x3e With the look up table created then started writing the program by importing any needed files and defining my variables Note that only ACCEL IS imported from the OpenElectrons LSM303 _ file Because the LSM303 chip contains a magnetometer as well as an accelerometer the library contains two separate classes Also notice the str variable This is the string the magic wand will display import time import os sys from OpenElectrons i2c import OpenElectrons i2c from OpenElectrons LSM303 import ACCEL test 1 oe OpenElectrons 12c 0x38 Lsm ACCELO str MagPi Rocks length len str index Q test 1 of Seren t 5 print str The while loop starts by turning off the LEDs Next it reads the accelerometer value along the X axis then quickly reads the value again With these two values a simplified calculation of acceleration can be performed while test 1 turn leds off oe simpleWriteByte Oxff get first value array lsm readArray lsm ACCEL X Y Z 0x80 6 aclraw lsm accl array Q time sleep t get second value array lsm readArray lsm ACCEL X Y Z 0x80 6 aclraw2 lsm accl array 0 divide values to compen
33. ery easy The magnetometer reads the Earth s magnetic field so readings will be different depending on direction and location Useful links OpenElectrons com full magic wand project kit and program http www openelectrons com pages 63 OpenElectrons com SmartUPS http www openelectrons com pages 33 ey e of cooccoo s eso ococccoco tc 4 i zik AL Hii i TUTTA 1 IU LLELE E Deo p mn 4 e z N T j 7 T5 er 3 on y BESTRNEEENEBNMEN A A VISITUSON f WORLD S MOST VERSATILE NT Model 209 VACUUM BASE PV JR Model 201 e Work holding tools for electronics projects JOEY S e Circuit board holders make 5c soldering easy amp fun thier e Versatile hobby vises for any project PANAMISE Innovative Holding Solutions ee E E reti Model 207 VISE BUDDY JR PIMO ea PANAVISE IS AVAILABLE AT RONI A http shop pimoroni com it jj 059 1 Wi PI CANVAS Digital artdisplay How to display dynamic art using a Raspberry Pi In the past digital artists have been limited to static images prints when creating wall art The Pi Canvas allows digital art to be created and displayed on a wall just like a framed print However the art is now dynamic which opens up new creative opportunities In this article will describe how you can make a Pi Canvas using your Raspberry Pi to produce a display of dynamic art art whic
34. ff anytime soon The Raspberry Pi is here to stay that is now a well known fact Both the Foundation and the community that surrounds the Raspberry Pi have produced some incredible software and hardware and has achieved some pretty amazing things balloon flights to space visits to Buckingham Palace and perhaps most importantly and most relevantly to the Foundation s charitable goals inspiring a huge number of people to get involved with computing electronics and STEM As you probably already know in the early hours UK time on the 14th July 2014 the Raspberry Pi Foundation announced the latest hardware upgrade the Raspberry Pi Model B This represents the first major hardware change to the Raspberry Pi board since the upgrade of the Model B hardware to 512 MB of RAM in October 2012 There had been some minor changes to various components in the interim period likely due to pricing and supply issues or similar as well as the release of both the Camera Module Pi NoIR and the Compute Module Additionally MODEL B First look and introduction mem AAA TITIIIITTIII III AN a Aaron Shaw MagPi Writer as some of the more eagle eyed of you may have noticed more recently around April 2014 the USB hub and LAN chip on the Model B had also been upgraded from a LAN9512 to a LAN9514 chip as well as a general redesign of the PCB Looking at the documentation that comes in the box with the Raspberry Pi it look
35. h can optionally interact with viewers What is Pi Canvas Pi Canvas is a Raspberry Pi mounted on an HDTV that has a USB connector to power the Raspberry Pi The Pi Canvas has no keyboard no mouse nor does it respond to the TV remote control It is simple to use Just hang it on the wall plug it in press the power button and let it do its thing The Pi Canvas can operate 24 7 or be powered on and off as required It can also be made to interact with its environment through electronic sensors e g ultrasonic or infrared which opens up even more creative opportunities How to make a Pi Canvas The hardware and software used are all popular open source and well documented Basic knowledge of the hardware and software is not covered here as there are many excellent tutorials available online The Pi Canvas was developed in the Faulhaber Fab Lab at the Suncoast Science Center in Sarasota Florida It supports STEAM education Science Technology Engineering Art Mathematics for al ages For more details please visit http www suncoastscience org Pi Canvas hardware The Pi Canvas hardware requirements are simple Raspberry Pi model A or B e USB lt gt micro USB cable for power e HDMI male to male coupler HDTV e g VIZIO model E390 A1 While any HDTV can be used the example HDTV is particularly good as it has a USB connector sufficient for powering the Raspberry Pi It also has a recessed ar
36. hat we have something more substantial let s take a proper look at what is going on We ll explain each section of the code line by line MagPi Game Anything displayed after the one the same line is ighored This allows us to add comments to make the program easy to understand PROC Setup Tells the program to jump to the procedure called Setup run whatever is there and return when it comes to the ENDPROC command CYCLE PROC ScreenUpdate REPEAT These three lines define our main program loop Whatever is between the CYCLE REPEAT loop will be repeated indefinitely END END signifies the end of the program When the program executes the command it will return to Direct mode In our program this can only happen when Esc is pressed DEF PROC ScreenUpdate This starts the definition of the ScreenUpdate procedure It will update everything on the screen plotSprite Ship ShipX ShipY 0 The plotSprite command draws a sprite Ship at screen coordinates X ShipX and Y ShipY using version Having different versions of a sprite enables animation UPDATE When we draw graphics to the screen they are actually drawn to a background screen The UPDATE command copies the background screen to the main screen This keeps everything running smoothly and simplifies game programming ENDPROC Return back to where the procedure was called DEF PROC Setup The Setup procedure is deliberately placed at the
37. ike to use instead of buying them My recommendation would be to look for window motors or electric toy car motors decided to use the SmartDrive because it is capable of supporting up to 300W per motor though only used motors that ran at 22W each There is definitely more headroom to use the SmartDrive for more serious projects As mentioned previously the SmartDrive allows the Raspberry Pi to control up to two high current motors The SmartDrive is controlled by the Raspberry Pi using the I C interface The programming interface API is coded in Python and contains various different functions that allow you to control the motors in a variety of different ways Two motors can be connected to the SmartDrive the two black screw terminals labeled M1 and M2 The third black screw terminal is for power lt is also possible to program the SmartDrive with the C language There are functions that allow you to run the motor in terms of degrees turned time run in seconds and even for a certain number of rotations It also supports rotary encoders A nice bonus feature of the SmartDrive is that it is capable of providing a 5V output which can be used to power the Raspberry Pi without using another power source Parts List 1 SmartDrive http www openelectrons com pages 34 2 Tempest TR1 3 12 Battery 12V http www tempestbatteries com html tr1 3 12 html 3 DreamGrear Shadow USB wireless joystick http www dreamgear
38. ing the SmartDrive add on board How to control a robot with a joystick The Raspberry Pi is amazing in the sense that it can be used to create programs for almost any purpose l ve seen people create media centres cloud storage devices weather stations video game emulators and various other implementations on this little computer However wanted to start off with something that didn t require lots of software maintenance and decided upon creating a remote controlled robot The hardware specifics of this robot will vary from user to user therefore want to focus on the coding required to get the robot to move use a joystick to control my robot To control the motors use a SmartDrive controller This is a motor driver that allows you to control up to two high current motors with the Raspberry Pi When starting this program it is important to import the following modules import pygame import sys os from SmartDrive import SmartDrive The pygame module is used to create a joystick object the sys module is to be able to quit the program when prompted and the os module is to read the string environment This is the code to create the joystick object try j pygame joystick Joystick j initQ print Enabled joystick j get name except pygame error print no joystick found A try except block is recommended because it is important to be able to catch the exception of a pygame error for debugging
39. input range We have to change the input range with the channel control for Channel A 7 to an appropriate value While working with an osciloscope you should always be aware about the settings of the instrument and the expected voltages in the circuit Is this NE555 timer IC still working In our next experiment we want to find out if a NE555 timer IC is still functional This IC is often used when a clock signal is required For this experiment we need e 2x 1K resistors R1 R2 0 1 uF capacitor C1 e 10 nF capacitor C2 e NE555 timer IC IC1 e small breadboard e test leads provided with the BitScope Micro Fig 5 shows the circuit diagram and Fig 6 shows you how to implement this circuit on a breadboard C1 Fig 5 Circuit diagram of the clock generator gt gt i H e 4 ui i Y A N S 27h IC1 NE555 4 o5 rrrrga I cinesss DNE Nd Pini 3 Ge Voc 5V EB gt i e wane Gnd a m 1 Ls g l i eee lt R1 1kOhm we K m 00 Ge yy NN 2107 EE CUN ee ON CiO iuF m SS See eee Lm a ee Ded 3 ae US MP em C n ss Fig 6 Implementation on a breadboard When you have finished building the clock generator on the breadboard set the time base control 6 to 50 usec per Div and the channel control pad for Channel A 7 to 2V per Div Additionally set the trigger controls 4 to MEAN Our R
40. installations where neat installation is very important For people who like neatness and aesthetics the round edges on the new PCB are probably also a welcome addition Looking at the top of the board there are now only two LEDs on the top power and activity and they have been relocated to the same side as the DSI port The Ethernet connection and activity lights are still present but are now located inside the Ethernet jack itself which both looks great and saves space Looking at the comparison of the Model B boards from the different suppliers on the previous page there are some small differences in component selection see the USB HDMI CSI and DSI ports am not sure if this is down to the manufacturers sourcing components of their own or whether this is just a coincidence In either case the boards are both made in the Sony factory in Wales and look fantastic There are some less noticeable changes under the hood with the Model B getting an updated power circuit that replaces linear regulators with switched ones in order to reduce power consumption by up to 1 Watt The audio circuit also now incorporates a dedicated low noise power supply which should improve the quality somewhat and the USB ports can now be fed with up to 1 2 Amps as well as featuring better overcurrent and hotplug behaviour plugging and unplugging devices while the Raspberry Pi is running Getting started Hopefully you like me are fortunate en
41. itled Loose Weave Digital Fabric In April it won an award at the Art Center Sarasota One World exhibition The artwork creates a new digital fabric every ten minutes Drawing the digital fabric is an important visual aspect of the artwork and takes about five minutes The fabric colour is random and the thread colours are random within 45 degrees of the fabric colour on the HSLA Hue Saturation Lightness Alpha colour wheel Pi Canvas sample artwork code Here is a sample artwork file which draws a starburst approximately every 10 seconds The hues remain within 30 degrees of the initial random hue on the HSLA colour wheel What happens if you change the values of dhue or tension lt DOCTYPE html gt lt html gt lt head gt lt meta charset UTF 8 gt lt title gt Starburst lt title gt lt script type application javascript gt var interval 10 var canvasWidth 800 var canvasHeight 000 var x var y var count Q var hold 1000 var hue Math random 360 var dhue 30 var tension 1 var fiberHue hue Math sin Math random Math PI 2 dhue var fiberColor hslaC fiberHue 100 50 1 setInterval eachTick interval function initialize 1 var ccedocument getElementByIdC canvas1 getContextC 2d cc save cc translate 400 300 hue Math random 360 function eachTick 4 count count 1 1fCcount gt
42. k generator is running For the answer you should look at Fig 8 or the measurement on your own screen and remember what wrote about measuring frequencies in Part 1 last month As an aid have drawn a line in red on the output diagram showing that the period of the square wave is 200 usec In this second part we measured voltage and frequency In the next part there will be some more experiments with the clock generator and how to put an oscilloscope to good use The BitScope Micro add on board is available from BitScope Designs in X Australia http www bitscope com in Germany from BUTTE publishing company http www butte verlag de in the UK from Pimoroni http shop pimoroni com and in Switzerland from http www pi shop ch A German translation of this article is available at http www butte verlag de 28 ADCOC DAGC P 2x 12 bit analogue to digital channels and 2x 12 bit digital to analogue channels IO Pi 32 digital input output channels for your Raspberry Pi Stack up to four IO Pi boards to give you 128 I O channels RIC PI Real time clock with battery backup and 5V F C level converter for adding external 5V I C devices to your Raspberry Pi ADC P 8 channel analogue to digital converter I C address selection allows you to add up to 32 analogue channels to your Raspberry Pi Com PI RS232 and 1 Wire expansion board adds a serial port to your Raspberry Pi Ideal for the Model
43. ly which will be extremely useful in schools and clubs with children and beginners Model B Raspberry Pi with mechanical sample of HAT board 24 kk E wwesueuweuwewewe E eee r Li Turn Your Raspberry Pi into a Robot s 2 gt s Oy Dy 7 ay TA ADSIDUE DRM BERS AT Arduberry Unite the Raspberry Pi and Arduino BitScope Digital Analog ARE Electronic measurement with BitScope Part 2 SKILL LEVEL INTERMEDIATE In last months article we equipped the Raspberry Pi with a BitScope Micro add on board and installed the BitScope digital storage oscilloscope DSO software Now we are ready to delve into the fascinating field of electronic measurement with a fully fledged DSO 3 ae A NT GRY power sevup SCOPE Fig 1 BitScope DSO software main screen elements photo courtesy by BitScope Designs In Part 1 you learnt that an oscilloscope measures electrical voltages So let s start by measuring the voltage of the Raspberry Pi itself Identify the channel control pad for Channel A 7 and set it to 2V per Div This means that one square of the y axis on the main screen OSCILLOSCOPE Add on board pl raspberrypl Karl Ludwig Butte Guest Writer represents 2V With 8 squares stacked up on the Y axis we are able to measure a maximum of 16V Now connect the red test lead to pin CHA and the black test lead to pin GND opposite pin CH
44. ned in the malt To optimise the conversion to sugar by the enzymes multiple resting periods at different temperatures are needed These temperatures have to be held for specific times That s the point where MashBerry is used After mashing the malt is separated from the wort in a process called lautering It is basically a kind of filtering After the lautering the wort is boiled with hops In this step the beer gets hop flavours and bitterness Additionally some chemical processes take place while boiling These processes for example will clean the wort from the proteins After boiling the wort is cooled down and yeast is added to ferment the beer in this step the yeast is producing the alcohol After fermentation the beer is bottled and aged for several weeks or months depending on the type of beer Then it s ready to drink Composite GPIO Hardware 2C THMOD PT1000 GPIO DS1820 GPIO SSR To use a Raspberry Pi as a brewing controller two main interfaces had to be added The first interface is a temperature sensor for measuring the temperature of the mash There are two possibilities for temperature sensors a cheap DS1820 sensor or a more accurate PT1000 sensor with a Hygrosens I C converter module The Hygrosens module THMOD I2C R2 is a small module with an 1 C interface that directly converts the value read from a PT1000 sensor to a usable temperature To use this converter
45. nistration Get Support User Control Panel Click on FreePBX Administration The default login is admin with the password admin The Applications menu has various options including Extensions Conferences and Ring Groups Click on Extensions As no extensions exist you will add a new extension For the Device option choose Generic SIP Device then click on Submit to go to the next page There are many options but we will just set the User Extension to 300 the Display Name to Walberto and the secret option to ext300 Click on Submit to add the extension Applications v Connectivity v Reports v Settings v Apply Config Add SIP Extension Ke Admin v Add Extension User Extension 300 Display Name Walberto CID Num Alias SIP Alias Outbound CID Asterisk Dial Options tr Override Ring Time Default Call Forward Ring Time Default v Outbound Concurrency Limit No Limit v Call Waiting Enable v Call Screening Disable v Pinless Dialing Disable v Emergency CID Queue State Detection Use State On the right side of the screen click on 300 to view the extension you just added Verify the port option is set to 5060 Click on Submit then click on the red Apply Config button to save your changes Repeat this procedure for the other extensions that you want to create created extensions 301 and 302 We now configure the IP phone extensions This will vary by device but w
46. ogin as root with the password raspberry If you wish you can do this remotely On Windows install the PuTTY SSH client and connect using root raspbx On an Apple Mac simply open the Terminal and enter ssh root raspbx Local Later you will want to disable root login via SSH as this is a security weakness Once logged in the first command you want to run is raspbx upgrade This will update all the software to the latest version including Raspbian and the kernel sername Fr gt 7 EET user root root raspb password R i E The next thing you need to do is set up a static IP address You need to specify the static IP address you want to use the network mask and the gateway of your router or cable modem The ifconfig command will provide your current IP address and the network mask Your new static IP will have the same first three octets as your current IP The last octet must be outside the range that your router uses for dynamic IP addresses To find the gateway address enter netstat r Edit the tnterfaces file with the command nano etc network interfaces Your interfaces file will look something like the screenshot below Note that you need to replace the word dhcp on the eth0 line with the word static Also be sure to press the Tab key once to get the desired indendation File Edit Tabs Help GNU nano 2 2 6 File etc network intertaces Used by ifup 8 and ifdown 8 See th
47. or username 302 at realm asterisk UserID 302 Password eeeeee Sok M cancel With FreePBX and Asterisk you can implement various services like conference rooms IVR Interactive Voice Response call groups plus incoming and outgoing calls via the normal PSTN SIP trunk lines or the internet The Future The development of communications using VoIP and the internet is driving the convergence of Unified Communications systems into a single system and environment FreePBX and Asterisk is a superb example of how sophisticated communication systems can be implemented for very low cost P TN CED we b te d d C9 lN co 609 09 Q 5 56 4 a g lt w J u E 3 The MagPi What s On Guide Want to keep up to date with all things Raspberry Pi in your area Then this section of The MagPi is for you We aim to list Raspberry Jam events in your area providing you with a Raspberry Pi calendar for the month ahead h Are you in charge of running a Raspberry Pi event Want to publicise it Email us at editor themagpi com Southend Raspberry Jam When Saturday 16th August 2014 10 00am to 5 00pm Where Tickfield Centre Tickfield Avenue Southend on Sea SS2 eLL UK There will be talks show and tell workshops videos robots and lots of fun Learn how to code in scratch Blockly and Python http soslug org node 2023 Haspberry Jam Silicon Valley When Saturday
48. ough to use an SD card with the Raspberry Pi that is actually a microSD card in a holder Personally use the official SD card with the Raspberry Pi logo silk screened on the holder This means did not have to purchase a new SD card in order to get started with the Model B However due to the new firmware needed it is not necessarily quite as easy as just swapping the SD card out of the old Model B and into the Model B There are a few steps you may need to undertake first This is especially important if you have not updated your operating system in a while Open an LX Terminal window and type the following to make sure the software on your SD card is up to date sudo apt get update sudo apt get upgrade Raspberry Pi HATs With the update to the Model B the Raspberry Pi Foundation also recently announced the specification for what they are calling HATs Hardware Attached on Top The idea is to have a more regulated framework for add on boards as well as just having a nice name to use for them similar to Beaglebone Capes and Arduino Shields The specification outlines a mechanical shape as can be seen in the picture below which makes use of the 40 pin header as well as all four of the mounting holes All HATs must also have an EEPROM on board which will contain code that allows the Raspberry Pi to automatically identify the add on board and set up the GPIO pins and Linux drivers necessary to get you up and running quick
49. re are many variations of mashing but the single infusion mash is easily done with home equipment and suitable for most popular beer styles Lautering is a process in brewing beer in which the mash is separated into the clear liquid wort and the residual grain Lautering usually consists of 3 steps mashout recirculation and sparging Add the power of speech hearing and vision to your robot Part 2 SKILL LEVEL INTERMEDIATE Introduction Part 1 of this article in Issue 25 provided an introduction to robotics and gave practical tips for how you can build a fun little robot with your Raspberry Pi In this second part we will cover some more advanced explorations into Raspberry Pi robotics and demonstrate how the Raspberry Pi can be used to create some impressive robotic behaviours and systems Three areas will be introduced that each have immense value for useful robotics These are text to speech voice recognition and computer vision Each of these relate to an aspect of human centric abilities speech hearing and vision We saw in Part 1 how robotics is about making computing real world and also that useful robots can sense process and then act in the world intelligently In each of our chosen areas we will introduce the technology and give a simple example of how it can be used to do something interesting in a robotic application The first two areas text to speech and voice recognition are both to do with so
50. ront of other scripts with similar words it will be We will set ours at 10 for now If there is another script with priority less than 10 and it has dance in its WORDS array then our script will be used because it has a higher priority PRIOIRTY 10 The i1sValid C function checks the transcripted text input from Jasper s audio recognition engine to determine if this is the correct script This will check the input from the user and return true if this script is related to the input text def isValid text return bool re search r NbdanceNb text re IGNORECASE The handleC function will basically perform an action in relation to the input Here is where Jasper will respond to the input You will need to pass text mic and profile as variables which give you more options with Jasper In this example get Jasper to acknowledge that it is going to dance and then call a function from our PiBot script to get Jasper dancing def handle text mic profile mic sayC Yeah sure watch these moves PiBot dance Here is the full script __author__ alexgray import PiBot import re WORDS dance PRIORITY 10 def is valid text Return True if input relates to dance Arguments text user input typically transcribed speech return bool re search r NbdanceNb text re IGNORECASE def handleCtext mic profile Makes PiBot dance Arguments text user input typically transcribed
51. rything you need to maximise your enjoyment of the Raspberry Pi it also includes an OWI programmable robotic arm kit Second prize is the superb FUZE T2 A kit worth 180 Again this contains everything you need including a Raspberry Pi Model B solderless breadboard various electronic components SD card with FUZE BASIC printed Programmer s Reference Guide and much more Third prize is the excellent FUZE T2 C kit for your Raspberry Pi Worth 80 this kit contains the FUZE case keyboard integrated USB hub FUZE I O board and power supply Details of the prizes can be found at http www fuze co uk products Over the coming months you will learn everything that you need but if you want to give yourself a head start then download the FUZE BASIC Programmer s Reference Guide from http www fuze co uk resources 2 The FUZE is what T F U 7 the Raspberry Pi was designed for i FUZE Type II for Raspberry Pi B amp the new B Protect your Pi from physical amp static damage UK keyboard amp 4 Extra USB ports FUZE I O Board with GPIO pass thru Clearly labeled input output ports FU Z E 2 Amp power supply and on off switch Q Adds analogue ports 4 in amp 1 out s Prices start from 89 99 See FUZE website for details The MagPi is available for FREE from http www themagpi com from The MagPi iOS and Android apps and also from the Pi Store However because so m
52. s like the change may have been related to FCC class B device certification However the change in LAN USB chip is likely to have also been a hardware trial of sorts before the more obvious changes were made in the Model B which actually make use of the additional functionality present in the upgraded LAN USB chip Raspberry Pi Model B Ske 811 1284 7 Raspberry Pi B New Raspberry Pi packaging o c n Where to buy As per usual the Raspberry Pi Model B available to purchase from the two main distributors RS Components and Farnell element 14 and their subsidiaries It is also already in stock along with a selection of accessorries at a number of independent retailers across the world First impressions Whether the Model B board that you purchase has originated from an RS Components or Farnell batch the first thing you are likely to notice is the fantastic new packaging designs as can be seen on the picture on the bottom of the last page My personal preference is the Farnell packaging however they are both a significant improvement on the original packaging basically a plain white box and the product already looks far more professional with that simple step wii Sos me treet Ci Opening the box and taking a look at the new board the changes are fairly obvious and this is even more apparent if you look at the picture to the right comparing the new Model B
53. s the Raspbian boot image but configured with the latest version of FUZE BASIC You will need to unzip the boot image file and install it onto an SD card Please note that you need a minimum 8GB SD card You also need software to install the image onto the SD card Windows users can use Win32Disklmager but full installation details for Linux MacOS and Windows are available from the official Raspberry Pi website at http www raspberrypi org documentation installation installing images Next boot your Raspberry Pi with your new FUZE image There isn t anything particularly FUL ZIE different with the boot f image compared to the Bi standard Raspbian EMI image except for a new Desktop background image and a FUZE BASIC icon First open the Fuze folder and then open the Programs folder Inside this create a new folder called MagP1 We are going to create a game with this tutorial so the next thing is to download the graphics Please go back to hitp www fuze co uk and to the Resources page Click on the Tutorials tab and download the six sprites contained in The MagPi Tutorial section These sprites are the player s rocket ship the enemy rocks and the ever important bullet Download and copy these six files into the MagP1 folder we created earlier Godd On the FUZE desktop double click the cWaEd FUZE BASIC icon to start FUZE NM BASIC The welcome screen will appear and you will be presented with the Rea
54. sate for gravity and subtract to find delta acl aclraw2 g aclraw g filter approximate still values if acl lt 30 and acl gt 30 acl 0 The following if statement and while loop actually light the LEDS The while loop accesses the look up table for every letter in the string one at time This allows any message inserted into the str variable to be displayed without any other changes in the program if moving from right to left display string if acl 0 time sleep 15 while index length for number in lookuptable str index oe simpleWriteByte number index index 1 turn off leds for a short time to account for letter spacing oe simpleWriteByte Oxff time sleep 0015 reset string index Q A link to the code in its entirety is shown below Have fun creating images and messages with your own magic wand LSM303 Magnetometer When creating your own magic wand you may come across various issues with certain wand designs lf the wand changes direction at any given time you will encounter a rapid deceleration This causes the static and dynamic accelerometer readings to clash resulting in unwanted input data If you are a mathematician or are extremely knowledgeable about advance physics concepts this may be a fun project for you But for everyone else you may want to use the LSM303 magnetometer The code has a few differences but once you figure out the proper magnetic readings it is v
55. should have a blank screen in the Editor If not then try pressing F2 and F12 until you get there When you are in Direct mode you can type EXIT to exit the program Hight now we need to be in Direct mode with no program in memory I If you type NEW in Direct mode it will clear the memory so when you go into the Editor it will be blank In direct mode enter DIR Among other things you should see a directory called MagP1 if you did everything above Enter CD MagPi This will put us in the same directory or folder where we saved the sprites earlier When we create our program we want it to be in the same folder as the sprites Press F2 to go to the Editor and enter the following program MagPi Game PROC Setup CYCLE REPEAT END DEF PROC Setup ENDPROC Press F3 to run the program The first time it will ask you for a file name Enter MagP1 and press Enter The FUZE BASIC Editor automatically adds the file extension fuze to file names When you press Enter the program will run but nothing of any interest will happen as we haven t done anything of interest yet If you have entered anything incorrectly you may get an error in which case F2 will take you back to the Editor If all is well the screen will just go blank as the program is in an infinite loop CYCLE REPEAT Press the Esc key and then F2 to return to the Editor Note you can get help at any time in the
56. speech mic used to interact with the user Cfor both input and output profile contains information related to the user e g phone Line Watch these moves mic sayCLine PiBot dance More details on Jasper can be found at http jasperproject github io Power of Vision The third area of advanced Raspberry Pi robotics is computer vision With the Raspberry Pi s HD camera module you now have the power to capture visual data Recently the excellent open source computer vision library OpenCV was implemeted on the Raspberry Pi This now gives great processing capabilities for analysing visual data and opens up a world of possibilities and useful applications Face recognition blob tracking motion detection and gesture mapping are all possible using OpenCV on the Raspberry Pi It is of course very exciting to implement these things on a robot First of all though we will need to install OpenCV on our Raspberry Pi We followed a guide from Adafruit to get OpenCV working with our project You can read it at httos learn adafruit com raspberry pi face recognition treasure box This also contains links to the image capture training and configuration scripts mentioned below In order to be able to recognise a face we need a number of pictures of that person We can do that with the X Python script capture positives py This accesses the Raspberry Pi camera so needs to run as root sudo python capture positives py
57. ss Karl Ludwig Butte continues his series on using a Raspberry Pi and BitScope for electronic measurement plus we have an interesting article by Walberto Abad on how to set up your own VoIP telephone system Last but definitely not least Jon Silvera continues his series on learning how to program with FUZE BASIC This is an exciting article with lots to discover certainly don t remember ever being able to control sprites this easily with BASIC We try to make sure each issue of The MagPi contains something of interest for everyone regardless of age and skill level Have we got the balance right Let us know by sending an email to editor themagpi com or comment on our Facebook page at hitp www facebook com MagPiMagazine Finally a big thank you to all the volunteers who work hard behind the scenes to produce The MagPi for your enjoyment and education Pm SC Let s get started Chief Editor of The MagPi he MagPi Team Ash Stone Chief Editor Administration Colin Deady Layout Testing Proof Reading lan McAlpine Issue Editor Layout Proof Reading Dougie Lawson Testing W H Bell Administration Nick Liversidge Layout Proof Reading Bryan Butler Page Design Graphics Age Jan John Stap Layout Matt Judge Website Administration Claire Price Proof Reading Aaron Shaw Layout Rita Smith Proof Reading Nick Hitch Administration MAGIC WAND Persistence of vision build a magic wand with an accel
58. t camera while True If we see a face is it recognised if face detect camera print Hi there nice to meet you Robotic Future These topics are quite advanced so if you ve managed to follow this article completely then you are doing very well There are lots of resources online if you want to explore any of these topics further In particular a number of detailed articles are found on the PiBot website at http www pibot org how to and we will be adding more as our adventures into Raspberry Pi robotics continue We are now working on computer vision voice recognition and text to speech for our PiBot robot and all this code will be open source and shared with the community too don t know about you but we are excited about making use of the incredible software that is now available on the Raspberry Pi for robotics Thanks to the Raspberry Pi and its community we can now make a robot that is able to hear you recognise your face and speak to you as well Exciting times indeed Thanks to Aldi Rina Alex Gray and Steph Tyszka from PiBot for their contributions to this article mE A brief introduction to the latest Raspberry Pi hardware release The first Model B Raspberry Pi was originally launched for sale on the 29th February 2012 In two short years our favourite little computer has racked up some pretty serious sales with over 3 million units sold to date and there are no signs of the rate of sale tailing o
59. t hurt Watch where you are going Ouch be careful Speak random choiceCresponses espeak synth speak Power of Hearing One very promising project have discovered for robotics is called Jasper This project claims that you can control anything with your voice and their website goes on to explain that Jasper is an open source platform for developing always on voice controlled applications For years voice control has been an aspirational technology for the world s most advanced and expensive robots and it is remarkable that this free software now makes this achievable with an inexpensive Raspberry Pi robot Jasper works by identifying specific spoken words trigger words that then can activate an action e g execute a Python function The spoken words that you want to use as triggers are given to Jasper through a string list Each Python script that you want to use with Jasper needs to contain a string list called WORDS an isValid function and a handle C function The isValid function relates to words being recognised and the handle C function relates to actions that occur The WORDS string array holds the words that you want to extract from the speech As an example let s choose the single word dance We will declare it like this as JJ WORDS dance We will also want to set the priority this script has over other scripts The higher the number the more important and further in f
60. und With a low cost microphone a speaker and a Raspberry Pi a world of possibilities opens up and this has been a reason why l ve included them in my PiBot project that have been developing PIBOT Give your Raspberry Pi robot powers Harry Gee Guest Writer A speaker gives the robot the power to talk make interesting sounds and play music Adding a microphone adds the ability of voice recognition as well as sensing the robot s acoustic environment First let s cover making a Raspberry Pi robot talk using text to speech Power of Speech The best text to speech or TTS solution have found for the Raspberry Pi is eSpeak It has a good range of voices and is not too resource CO intensive meaning it leaves processing power for other things too As well as being lightweight eSpeak provides a simple and straight forward command line interface that can be easily integrated into Python as well as other languages It even allows us to record straight to a WAV sound file with a simple option in the command line Best of all it has a Stephen Hawking esque sound that gives it a fitting dose of panache It is also good fun finding out what it mispronounces To get started the best thing to do is to just try installing eSpeak and see if it works out of the box If you are not using HDMI audio do not forget to have an amplified speaker or headphones plugged in to your Raspberry Pi For help in setting up audio or
61. with the old Model B The most important changes in my opinion are the inclusion of a 40 way GPIO header instead of 26 on the Model B four USB ports instead of two and the change to using a microSD card instead of a full size one As mentioned above this change to 4 USB ports is possible due to the change to a new LAN USB chip LAN9514 This is the little black chip just behind the USB ports Further changes include the relocation of the 3 5mm jack removal of the RCA video output jack the composite video signal has been relocated to the fourth pole on the 3 5mm jack and the addition of four squarely positioned mounting holes The new microSD card holder is now of the push push type so it is held securely in place when compared to the friction fit of the old one and also gives a nice click when it is correctly inserted Comparison between Model B and Model B boards You will probably also notice from the comparison picture that the USB ports no longer hang off the edge as far and are now lined up with the Ethernet port There has also been a general tidy up of the design and the major ports excluding the GPIO and DSI connectors now all lie on just 2 sides of the board Obviously some Comparison between RS Components left and Farnell element14 right boards of the connectors have had to be shifted around slightly to accomodate this This should allow for some much neater cabling for home cinema and professional
62. ye W Project parts list b 1x Raspberry Pi 1x Pi Prototyping kit OpenElectrons com 1x LSM303 breakout OpenElectrons com 1x SmartUPS OpenElectrons com 1x PCF8574 chip manufacturer part PCF8574ADW 1x 10uF through hole capacitor ESK106M050AC3AA 2x 82K through hole resistors 271 82K RC 8x 4mm flat top red diff LEDs HLMPM201 Build a magic wand with an Obtaining parts To build the circuit used the Pi Prototyping Kit from OpenElectrons com It has multiple integrated circuit footprints and unwired through holes for great prototyping flexibility For the accelerometer used the LSM303 breakout board also from OpenElectrons com Magic wand assembly The circuit build Pe enm for the magic s nee wand required soldering of through hole I components as wel as the surface mount PCF8574 chip The datasheet showed the In Out ports of PO P7 to which connected the eight LEDs In the first build placed a bussed resistor array between the 5V power and the LEDs to limit the current but when tested realized the lights were extremely difficult to see in the daylight then shorted the resistor array and the LEDs became much more visible Connecting the LSM303 breakout was by far the simplest part The Pi Prototyping board has two lC female connections for a quick plug in for breakout boards The full schematic for the project is shown below IC1IC 1 penoeeseteees

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