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• Today's The 4:30 movie: Java vs. C++

  - by hinkmond

  Here's a slide show that's paraphrasing Cameron Purdy's presentation on how Java technology has and hasn't supplanted C++. See: Why Java Has/Hasn't Won vs. C++ Here's a quote: This eWEEK slide show borrows from Purdy’s arguments and looks at 10 reasons Java was able to supplant C++, as well as five reasons or areas it was not. It's like Godzilla vs. Mechagodzilla. Can there really be a clear winner? Well, stick around and watch Godzilla vs. Mechagodzilla II on tomorrow's The 4:30 movie as Monster Week continues on WABC, and find out... Hinkmond

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• RPi and Java Embedded GPIO: Using Java to read input

  - by hinkmond

  Now that we've learned about using Java code to control the output of the Raspberry Pi GPIO ports (by lighting up LEDs from a Java app on the RPi for now and noting in the future the same Java code can be used to drive industrial automation or medical equipment, etc.), let's move on to learn about reading input from the RPi GPIO using Java code. As before, we need to start out with the necessary hardware. For this exercise we will connect a Static Electricity Detector to the RPi GPIO port and read the value of that sensor using Java code. The circuit we'll use is from William J. Beaty and is described at this Web link. See: Static Electricity Detector He calls it an "Electric Charge" detector, which is a bit misleading. A Field Effect Transistor is subject to nearby electro-magnetic fields, such as a static charge on a nearby object, not really an electric charge. So, this sensor will detect static electricity (or ghosts if you are into paranormal activity ). Take a look at the circuit and in the next blog posts we'll step through how to connect it to the GPIO port of your RPi and then how to write Java code to access this fun sensor. Hinkmond

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• Oracle releases ADF Mobile with Java ME CDC for iOS and Android

  - by hinkmond

  Finally. Oracle has released a new product that I've worked on for a while now. Oracle ADF Mobile is available for iOS and Android bringing Java ME CDC technology to iPhones and Android devices all over the world. Woot! Java. On iPhone and Android. Yeah, it's like that. See: Java and HTML5 on SmartPhones Here's a quote: Oracle announced the availability of Oracle ADF Mobile – a framework the enables the development of hybrid applications for mobile devices. Oracle ADF Mobile uses Java and HTML5 and enables developers to develop a single application that installs and runs on both iOS and Android systems. Java - Application logic is developed with the Java language. Oracle brings a lightweight Java VM embedded with each application so you can develop all your business logic in the platform neutral language you know and love! (Yes, even iOS!) Gosh, you'd think it was a big deal. Well, it was! So, go download yours today! Hinkmond

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• RPi and Java Embedded GPIO: Java code to blink more LEDs

  - by hinkmond

  Now, it's time to blink the other GPIO ports with the other LEDs connected to them. This is easy using Java Embedded, since the Java programming language is powerful and flexible. Embedded developers are not used to this, since the C programming language is more popular but less easy to develop in. We just need to use a dynamic Java String array to map to the pinouts of the GPIO port names from the previous diagram posted. This way we can address each "channel" with an index into that String array. static String[] GpioChannels = { "0", "1", "4", "17", "21", "22", "10", "9" }; With this new dynamic array, we can streamline the main() of this Java program to activate all the ports. /** * @param args the command line arguments */ public static void main(String[] args) { FileWriter[] commandChannels; try { /*** Init GPIO port for output ***/ // Open file handles to GPIO port unexport and export controls FileWriter unexportFile = new FileWriter("/sys/class/gpio/unexport"); FileWriter exportFile = new FileWriter("/sys/class/gpio/export"); for (String gpioChannel : GpioChannels) { System.out.println(gpioChannel); // Reset the port unexportFile.write(gpioChannel); unexportFile.flush(); // Set the port for use exportFile.write(gpioChannel); exportFile.flush(); // Open file handle to port input/output control FileWriter directionFile = new FileWriter("/sys/class/gpio/gpio" + gpioChannel + "/direction"); // Set port for output directionFile.write(GPIO_OUT); directionFile.flush(); } And, then simply add array code to where we blink the LED to make it blink all the LEDS on and off at once. /*** Send commands to GPIO port ***/ commandChannels = new FileWriter[GpioChannels.length]; for (int channum=0; channum It's easier than falling off a log... or at least easier than C programming. Hinkmond

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• Why are embedded device apps still written in C/C++? Why not Java programming language?

  - by hinkmond

  At the recent Black Hat 2014 conference in Sin City, the Black Hatters were focusing on Embedded Devices and IoT. You know? Make your networked-toaster burn your bread 10,000 miles away, over the Web for grins and giggles. Well, apparently the Black Hatters say it can be done pretty easily these days, which is scary. See: Securing Embedded Devices & IoT Here's a quote: All these devices are still written in C and C++. The challenges associated with developing securely in these languages have been fought for nearly two decades. "You often hear people say, 'Well, why don't we just get rid of the C and C++ language if it's so problematic. Why don't we just write everything in C# or Java, or something that is a little safer to develop in?'," DeMott says. Gah! Why are all these IoT devices still using C/C++? Of course they should be using Java SE Embedded technology! It's a natural fit to use for better security on embedded devices. Or, I guess, developers really don't mind if their networked-toasters do char their breakfast. If it can be burned, it will be... That's what I say. Unless they use Java. Hinkmond

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• RPi and Java Embedded GPIO: Hooking Up Your Wires for Java

  - by hinkmond

  So, you bought your blue jumper wires, your LEDs, your resistors, your breadboard, and your fill of Fry's for the day. How do you hook this cool stuff up to write Java code to blink them LEDs? I'll step you through it. First look at that pinout diagram of the GPIO header that's on your RPi. Find the pins in the corner of your RPi board and make sure to orient it the right way. The upper left corner pin should have the characters "P1" next to it on the board. That pin next to "P1" is your Pin #1 (in the diagram). Then, you can start counting left, right, next row, left, right, next row, left, right, and so on: Pins # 1, 2, next row, 3, 4, next row, 5, 6, and so on. Take one blue jumper wire and connect to Pin # 3 (GPIO0). Connect the other end to a resistor and then the other end of the resistor into the breadboard. Each row of grouped-together holes on a breadboard are connected, so plug in the short-end of a common cathode LED (long-end of a common anode LED) into a hole that is in the same grouping as where the resistor is plugged in. Then, connect the other end of the LED back to Pin # 6 (GND) on the RPi GPIO header. Now you have your first LED connected ready for you to write some Java code to turn it on and off. (As, extra credit you can connect 7 other LEDs the same way to with one lead to Pins # 5, 7, 11, 13, 15, 19 & 21). Whew! That wasn't so bad, was it? Next blog post on this thread will have some Java source code for you to try... Hinkmond

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• Internet of Things (IoT) Thanksgiving Special: Turkey Tweeter (Part 1)

  - by hinkmond

  It's time for the Internet of Things (ioT) Thanksgiving Special. This time we are going to work on a special Do-It-Yourself project to create an Internet of Things temperature probe to connect your Turkey Day turkey to the Internet by writing a Thanksgiving Day Java Embedded app for your Raspberry Pi which will send out tweets as it cooks in your oven. If you're vegetarian, don't worry, you can follow along and just run the simulation of the Turkey Tweeter, or better yet, try a tofu version of the Turkey Tweeter. Here is the parts list: 1 Vernier Go!Temp USB Temperature Probe 1 Uncooked Turkey 1 Raspberry Pi (not Pumpkin Pie) 1 Roll thermal reflective tape You can buy the Vernier Go!Temp USB Temperature Probe for $39 from here: http://www.vernier.com/products/sensors/temperature-sensors/go-temp/. And, you can get the thermal reflective tape from any auto parts store. (Don't tell them what you need it for. Say it's for rebuilding your V-8 engine in your Dodge Hemi. Avoids the need for a long explanation and sounds cooler...) The uncooked turkey can be found in your neighborhood grocery store. But, if you're making a vegetarian Tofurkey, you're on your own... The Java Embedded app will be the same, though (Java is vegan). So, grab all your parts and come back here for the next part of this project... Hinkmond

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• Freescale One Box Unboxing (then installing Java SE Embedded technology)

  - by hinkmond

  So, I get a FedEx delivery the other day... "What cool device could be inside this FedEx Overnight Express Large Box?" I was wondering... Could it be a new Linux/ARM target device board, faster than a Raspberry Pi and better than a BeagleBone Black??? Why, yes! Yes, it was a Linux/ARM target device board, faster than anything around! It was a Freescale i.MX6 Sabre Smart Device Board (SDB)! Cool... Quad Core ARM Cortex A9 1GHz with 1GB of RAM. So, cool... I installed the Freescale One Box OpenWRT Linux image onto its SD card and booted it up into Linux. But, wait! One thing was missing... What was it? What could be missing? Why, it had no Java SE Embedded installed on it yet, of course! So, I went to the JDK 7u45 download link. Clicked on "Accept License Agreement", and clicked on "jdk-7u45-linux-arm-vfp-sflt.tar.gz", installed the bad boy, and all was good. Java SE Embedded 7u45 on a Freescale One Box. Nice... Hinkmond

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• Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 5)

  - by hinkmond

  So, here's the finished product. I have 8 networked Raspberry Pi devices strategically placed around our Oracle Santa Clara Building 21 office. I attached a JFET transistor based EMF sensor on each device to capture any strange fluctuations in the electromagnetic field (which supposedly, paranormal spirits can change as they pass by). And, I have have a Web app (embedded in this page) which can take the readings and show a graphical display in real-time. As you can see, all the Raspberry Pi devices are blinking away green, indicating they are all operational and all sensors are working correctly. But, I don't see anything... Darn... Maybe, I have to stare at the Web app for a while. I don't know when the "alleged" ghosts in our Oracle Santa Clara office are supposed to be active, but let me know if you see anything... Oh, and by the way, Happy Halloween from the Internet of Spooky Things! See the previous posts for the full series on the steps to this cool demo: Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 1) Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 2) Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 3) Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 4) Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 5) Hinkmond

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• Skynet Big Data Demo Using Hexbug Spider Robot, Raspberry Pi, and Java SE Embedded (Part 3)

  - by hinkmond

  In Part 2, I described what connections you need to make for this demo using a Hexbug Spider Robot, a Raspberry Pi, and Java SE Embedded for programming. Here are some photos of me doing the soldering. Software engineers should not be afraid of a little soldering work. It's all good. See: Skynet Big Data Demo (Part 2) One thing to watch out for when you open the remote is that there may be some glue covering the contact points. Make sure to use an Exacto knife or small screwdriver to scrape away any glue or non-conductive material covering each place where you need to solder. And after you are done with your soldering and you gave the solder enough time to cool, make sure all your connections are marked so that you know which wire goes where. Give each wire a very light tug to make sure it is soldered correctly and is making good contact. There are lots of videos on the Web to help you if this is your first time soldering. Check out Laday Ada's (from adafruit.com) links on how to solder if you need some additional help: http://www.ladyada.net/learn/soldering/thm.html If everything looks good, zip everything back up and meet back here for how to connect these wires to your Raspberry Pi. That will be it for the hardware part of this project. See, that wasn't so bad. Hinkmond

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• Oh snap! My RPi was upgraded to 512MB! Woo-hoo!

  - by hinkmond

  I ordered a Raspberry Pi Model B (256MB) over 4 months ago on backorder. When it finally came I saw it was upgraded to the new half a gig model! Woot! But, all was not perfect. Gary C. told me the shipped configuration of the new RPi models didn't have the right firmware for 512MB, and I had to upgrade the start.elf in the /boot directory to recognize all of the 512MB RAM. I did a "free" command, and sure enough saw only 240MB. Sadness. But, Gary gave me a copy of his start.elf which worked after some trail and error. For anyone ordering the new RPi Model B w/512MB, here are the steps to get you going with full 512MB RAM: sudo apt-get update --fix-missing sudo apt-get upgrade --fix-missing # NOTE: This step takes at least a couple hours on a # fast network wget https://raw.github.com/raspberrypi/firmware/\ 164b0fe2b3b56081c7510df93bc1440aebe45f7e/boot/\ arm496_start.elf sudo mv /boot/start.elf /boot/orig-start.elf sudo mv arm496_start.elf /boot/start.elf sudo reboot free total used free shared buffers cached Mem: 497768 210596 287172 0 16892 169624 -/+ buffers/cache: 24080 473688 Swap: 102396 0 102396 So of course this means... (drumroll) there is now 498MB available for the Java Embedded heap! java -Xmx400m -version java version "1.7.0_06" Java(TM) SE Embedded Runtime Environment (build 1.7.0_06-b24, headless) Java HotSpot(TM) Embedded Client VM (build 23.2-b09, mixed mode) Yeah, baby! Hinkmond

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• Maker Faire Report - Teaching Kids Java SE Embedded for Internet of Things (IoT)

  - by hinkmond

  I had a great time at this year's Maker Faire 2014 in San Mateo, Calif. where Jake Kuramoto and the AppsLab crew including Noel Portugal, Anthony Lai, Raymond, and Tony set up a super demo at the DiY table. It was a simple way to learn how Java SE Embedded technology could be used to code the Internet of Things (IoT) devices on the table. The best part of our set-up was seeing the kids sit down and do some coding without all the complexity of a Computer Science course. It was very encouraging to see how interested the kids were when walking them through the programming steps, then seeing their eyes light up when telling them, "You just coded a Java enabled Internet of Things device!" as the Raspberry Pi-connected devices turned on or started to move from their Java Embedded program. See: The AppsLab at Maker Faire It will be interesting to see how this next generation of kids grow up with all these Internet of Things devices around them and watch how they will program them. Hopefully, they will be using Java SE Embedded technology to do so. From the looks of it at this year's Maker Faire, we might have a bunch of motivated young Java SE Embedded coders coming up the ranks soon. Well, they have to get through middle school first, but they're on their way! Hinkmond

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• Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 3)

  - by hinkmond

  So, let's now connect the parts together to make a Java Embedded ghost sensor using a Raspberry Pi. Grab your JFET transistor, LED light, wires, and breadboard and follow the connections on this diagram. The JFET transistor plugs into the breadboard with the flat part facing left. Then, plug in a wire to the same breadboard hole row as the top JFET lead (green in the diagram) and keep it unconnected to act as an antenna. Then, connect a wire (red) from the middle lead of the JFET transistor to Pin 1 on your RPi GPIO header. And, connect another wire (blue) from the lower lead of the JFET transistor to Pin 25 on your RPi GPIO header, then connect another (blue) wire from the lower lead of the JFET transistor to the long end of a common cathode LED, and finally connect the short end of the LED with a wire (black) to Pin 6 (ground) of the RPi GPIO header. That's it. Easy. Now test it. See: Ghost Sensor Testing Here's a video of me testing the Ghost Sensor circuit on my Raspberry Pi. We'll cover the Java SE app needed to record the ghost analytics in the next post. Hinkmond

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• Named my RPi 512MB @jerpi_bilbo

  - by hinkmond

  To keep our multiple Raspberry Pi boards apart from each other, I've now named my RPi Model B w/512MB: "jerpi_bilbo", which stands for Java Embedded Raspberry Pi - Bilbo (named after the Hobbit from the J.R.R. Tolkien stories). I also, set up a Twitter account for him. You can follow him at: @jerpi_bilbo He's self-tweeting, manual prompted so far (using Java Embedded 7.0 and twitter4j Java library). Works great! I'm setting him up to be automated self-tweeting soon, so watch for that... Here's a pointer to the open source twitter4j Java library: download here Just unzip and extract out the twitter4j-core-2.2.6.jar and put it on your Java Embedded classpath. Here's how @jerpi_bilbo uses it to Tweet with his Java Embedded runtime: import twitter4j.*; import java.io.* public final class Tweet { public static void main(String[] args) { String statusStr = null; if ((args.length 0) && (args[0] != null)) { statusStr = args[0]; } else { statusStr = new String("Hello World!"); } // Create new instance of the Twitter class Twitter twitter = new TwitterFactory().getInstance(); try { Status status = twitter.updateStatus(statusStr); System.out.println ("Successfully updated the status to: " + status.getText()); } catch (Exception e) { e.printStackTrace(); } } } That's all you need. Java Embedded rocks the RPi! And, @jerpi_bilbo is alive... Hinkmond

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• Quickie Guide Getting Java Embedded Running on Raspberry Pi

  - by hinkmond

  Gary C. and I did a Bay Area Java User Group presentation of how to get Java Embedded running on a RPi. See: here. But, if you want the Quickie Guide on how to get Java up and running on the RPi, then follow these steps (which I'm doing right now as we speak, since I got my RPi in the mail on Monday. Woo-hoo!!!). So, follow along at home as I do the same steps here on my board... 1. Download the Win32DiskImager if you are on Windows, or use dd on a Linux PC: https://launchpad.net/win32-image-writer/0.6/0.6/+download/win32diskimager-binary.zip 2. Download the RPi Debian Wheezy image from here: http://files.velocix.com/c1410/images/debian/7/2012-08-08-wheezy-armel/2012-08-08-wheezy-armel.zip 3. Insert a blank 4GB SD Card into your Windows or Linux PC. 4. Use either Win32DiskImager or Linux dd to burn the unzipped image from #2 to the SD Card. 5. Insert the SD Card into your RPi. Connect an Ethernet cable to your RPi to your network. Connect the RPi Power Adapter. 6. The RPi will boot onto your network. Find its IP address using Windows Wireshark or Linux: sudo tcpdump -vv -ieth0 port 67 and port 68 7. ssh to your RPi: ssh <ip_addr_rpi> -l pi <Password: "raspberry"> 8. Download Java SE Embedded: http://www.oracle.com/technetwork/java/embedded/downloads/javase/index.html NOTE: First click accept, then choose the first bundle in the list: ARMv6/7 Linux - Headless EABI, VFP, SoftFP ABI, Little Endian - ejre-7u6-fcs-b24-linux-arm-vfp-client_headless-10_aug_2012.tar.gz 9. scp the bundle from #8 to your RPi: scp <ejre-bundle> pi@<ip_addr_rpi> 10. mkdir /usr/local, untar the bundle from #9 and rename (move) the ejre1.7.0_06 directory to /usr/local/java That's it! You are ready to roll with Java Embedded on your RPi. Hinkmond

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• RPi and Java Embedded GPIO: Sensor Connections for Java Enabled Interface

  - by hinkmond

  Now we're ready to connect the hardware needed to make a static electricity sensor for the Raspberry Pi and use Java code to access it through a GPIO port. First, very carefully bend the NTE312 (or MPF-102) transistor "gate" pin (see the diagram on the back of the package or refer to the pin diagram on the Web). You can see it in the inset photo on the bottom left corner. I bent the leftmost pin of the NTE312 transistor as I held the flat part toward me. That is going to be your antenna. So, connect one of the jumper wires to the bent pin. I used the dark green jumper wire (looks almost black; coiled at the bottom) in the photo. Then push the other 2 pins of the transistor into your breadboard. Connect one of the pins to Pin # 1 (3.3V) on the GPIO header of your RPi. See the diagram if you need to glance back at it. In the photo, that's the orange jumper wire. And connect the final unconnected transistor pin to Pin # 22 (GPIO25) on the RPi header. That's the blue jumper wire in my photo. For reference, connect the LED anode (long pin on a common anode LED/short pin on a common cathode LED, check your LED pin diagram) to the same breadboard hole that is connecting to Pin # 22 (same row of holes where the blue wire is connected), and connect the other pin of the LED to GROUND (row of holes that connect to the black wire in the photo). Test by blowing up a balloon, rubbing it on your hair (or your co-worker's hair, if you are hair-challenged) to statically charge it, and bringing it near your antenna (green wire in the photo). The LED should light up when it's near and go off when you pull it away. If you need more static charge, find a co-worker with really long hair, or rub the balloon on a piece of silk (which is just as good but not as fun). Next blog post is where we do some Java coding to access this sensor on your RPi. Finally, back to software! Ha! Hinkmond

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• Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 4)

  - by hinkmond

  And now here's the Java code that you'll need to read your ghost sensor on your Raspberry Pi The general idea is that you are using Java code to access the GPIO pin on your Raspberry Pi where the ghost sensor (JFET trasistor) detects minute changes in the electromagnetic field near the Raspberry Pi and will change the GPIO pin to high (+3 volts) when something is detected, otherwise there is no value (ground). Here's that Java code: try { /*** Init GPIO port(s) for input ***/ // Open file handles to GPIO port unexport and export controls FileWriter unexportFile = new FileWriter("/sys/class/gpio/unexport"); FileWriter exportFile = new FileWriter("/sys/class/gpio/export"); for (String gpioChannel : GpioChannels) { System.out.println(gpioChannel); // Reset the port File exportFileCheck = new File("/sys/class/gpio/gpio"+gpioChannel); if (exportFileCheck.exists()) { unexportFile.write(gpioChannel); unexportFile.flush(); } // Set the port for use exportFile.write(gpioChannel); exportFile.flush(); // Open file handle to input/output direction control of port FileWriter directionFile = new FileWriter("/sys/class/gpio/gpio" + gpioChannel + "/direction"); // Set port for input directionFile.write(GPIO_IN); } /*** Read data from each GPIO port ***/ RandomAccessFile[] raf = new RandomAccessFile[GpioChannels.length]; int sleepPeriod = 10; final int MAXBUF = 256; byte[] inBytes = new byte[MAXBUF]; String inLine; int zeroCounter = 0; // Get current timestamp with Calendar() Calendar cal; DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss.SSS"); String dateStr; // Open RandomAccessFile handle to each GPIO port for (int channum=0; channum And, then we just load up our Java SE Embedded app, place each Raspberry Pi with a ghost sensor attached in strategic locations around our Santa Clara office (which apparently is very haunted by ghosts from the Agnews Insane Asylum 1906 earthquake), and watch our analytics for any ghosts. Easy peazy. See the previous posts for the full series on the steps to this cool demo: Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 1) Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 2) Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 3) Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 4) Hinkmond

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• RPi and Java Embedded GPIO: It all begins with hardware

  - by hinkmond

  So, you want to connect low-level peripherals (like blinky-blinky LEDs) to your Raspberry Pi and use Java Embedded technology to program it, do you? You sick foolish masochist. No, just kidding! That's awesome! You've come to the right place. I'll step you though it. And, as with many embedded projects, it all begins with hardware. So, the first thing to do is to get acquainted with the GPIO header on your RPi board. A "header" just means a thingy with a bunch of pins sticking up from it where you can connect wires. See the the red box outline in the photo. Now, there are many ways to connect to that header outlined by the red box in the photo (which the RPi folks call the P1 header). One way is to use a breakout kit like the one at Adafruit. But, we'll just use jumper wires in this example. So, to connect jumper wires to the header you need a map of where to connect which wire. That's why you need to study the pinout in the photo. That's your map for connecting wires. But, as with many things in life, it's not all that simple. RPi folks have made things a little tricky. There are two revisions of the P1 header pinout. One for older boards (RPi boards made before Sep 2012), which is called Revision 1. And, one for those fancy 512MB boards that were shipped after Sep 2012, which is called Revision 2. So, first make sure which board you have: either you have the Model A or B with 128MB or 256MB built before Sep 2012 and you need to look at the pinout for Rev. 1, or you have the Model B with 512MB and need to look at Rev. 2. That's all you need for now. More to come... Hinkmond

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• RPi and Java Embedded GPIO: Big Data and Java Technology

  - by hinkmond

  Java Embedded and Big Data go hand-in-hand, especially as demonstrated by prototyping on a Raspberry Pi to show how well the Java Embedded platform can perform on a small embedded device which then becomes the proof-of-concept for industrial controllers, medical equipment, networking gear or any type of sensor-connected device generating large amounts of data. The key is a fast and reliable way to access that data using Java technology. In the previous blog posts you've seen the integration of a static electricity sensor and the Raspberry Pi through the GPIO port, then accessing that data through Java Embedded code. It's important to point out how this works and why it works well with Java code. First, the version of Linux (Debian Wheezy/Raspian) that is found on the RPi has a very convenient way to access the GPIO ports through the use of Linux OS managed file handles. This is key in avoiding terrible and complex coding using register manipulation in C code, or having to program in a less elegant and clumsy procedural scripting language such as python. Instead, using Java Embedded, allows a fast way to access those GPIO ports through those same Linux file handles. Java already has a very easy to program way to access file handles with a high degree of performance that matches direct access of those file handles with the Linux OS. Using the Java API java.io.FileWriter lets us open the same file handles that the Linux OS has for accessing the GPIO ports. Then, by first resetting the ports using the unexport and export file handles, we can initialize them for easy use in a Java app. // Open file handles to GPIO port unexport and export controls FileWriter unexportFile = new FileWriter("/sys/class/gpio/unexport"); FileWriter exportFile = new FileWriter("/sys/class/gpio/export"); ... // Reset the port unexportFile.write(gpioChannel); unexportFile.flush(); // Set the port for use exportFile.write(gpioChannel); exportFile.flush(); Then, another set of file handles can be used by the Java app to control the direction of the GPIO port by writing either "in" or "out" to the direction file handle. // Open file handle to input/output direction control of port FileWriter directionFile = new FileWriter("/sys/class/gpio/gpio" + gpioChannel + "/direction"); // Set port for input directionFile.write("in"); // Or, use "out" for output directionFile.flush(); And, finally, a RandomAccessFile handle can be used with a high degree of performance on par with native C code (only milliseconds to read in data and write out data) with low overhead (unlike python) to manipulate the data going in and out on the GPIO port, while the object-oriented nature of Java programming allows for an easy way to construct complex analytic software around that data access functionality to the external world. RandomAccessFile[] raf = new RandomAccessFile[GpioChannels.length]; ... // Reset file seek pointer to read latest value of GPIO port raf[channum].seek(0); raf[channum].read(inBytes); inLine = new String(inBytes); It's Big Data from sensors and industrial/medical/networking equipment meeting complex analytical software on a small constraint device (like a Linux/ARM RPi) where Java Embedded allows you to shine as an Embedded Device Software Designer. Hinkmond

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• Developer Preview of Java SE 8 for ARM Now Available

  - by Tori Wieldt

  A Developer Preview of Java SE 8 including JavaFX (JDK 8) on Linux for ARM processors is now available for immediate download from Java.net. As Java Evangelist Stephen Chin says, "This is a great platform for doing small embedded projects, a low cost computing system for teaching, and great fun for hobbyists." This Developer Preview is provided to the community so that you can provide us with valuable feedback on the ongoing progress of the project. We wanted to get this release out to you as quickly as we can so you can start using this build of Java SE 8 on an ARM device, such as the Raspberry Pi (http://raspberrypi.org/). Download JDK 8 for ARM Read the documentation for this early access release Let Us Know What You Think!Use the Forums to share your stories, comments and questions. Java SE Snapshots: Project Feedback Forum  JavaFX Forum We are interested in both problems and success stories. If something does not work or behaves differently than what you expect, please check the list of known issues and if yours is not listed there, then report a bug at JIRA Bug Tracking System. More ResourcesJavaFX on Raspberry Pi – 3 Easy Steps by Stephen Chin OTN Tech Article: Getting Started with Java SE Embedded on the Raspberry Pi by Bill Courington and Gary Collins Java Magazine Article: Getting Started with Java SE for Embedded Devices on Raspberry Pi (Free subscription required) Video: Quickie Guide Getting Java Embedded Running on Raspberry Pi by Hinkmond Wong 

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• Java Spotlight Episode 112: Joonas Lehiten on @Vaadin

  - by Roger Brinkley

  Interview with Joonas Lehtinen on Vaadin. Right-click or Control-click to download this MP3 file. You can also subscribe to the Java Spotlight Podcast Feed to get the latest podcast automatically. If you use iTunes you can open iTunes and subscribe with this link:  Java Spotlight Podcast in iTunes. Show Notes News Java Smart Metering video JavaFX for Tablets and Mobile survey on FXExperience Muliple JSR Migrating to the Latest JCP Version A number of JEPs added to  JDK 8 features and JDK 8 Milestones Adopt-a-JSR for Java EE 7 Events Dec 14-15, IndicThreads, Pune, India Dec 20, 9:30am JCP Spec Lead Call December on Developing a TCK Jan 15-16, JCP EC Face to Face Meeting, West Coast USA Feature InterviewJoonas Lehtinen started the development of Vaadin, a Java-based open source framework for building business-oriented Rich Internet Applications. He has been developing applications for the web since 1995 with a strong focus on Ajax and Java. He is also the founder and CEO of the company behind the Vaadin framework. What’s Cool Hinkmond Wong’s work with RasberryPI and Java Embedded GPIO Collaborative Whiteboard using WebSocket

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• Series On Embedded Development (Part 1)

  - by user12612705

  This is the first in a series of entries on developing applications for the embedded environment. Most of this information is relevant to any type of embedded development (and even for desktop and server too), not just Java. This information is based on a talk Hinkmond Wong and I gave at JavaOne 2012 entitled Reducing Dynamic Memory in Java Embedded Applications. One thing to remember when developing embeddded applications is that memory matters. Yes, memory matters in desktop and server environments as well, but there's just plain less of it in embedded devices. So I'm going to be talking about saving this precious resource as well as another precious resource, CPU cycles...and a bit about power too. CPU matters too, and again, in embedded devices, there's just plain less of it. What you'll find, no surprise, is that there's a trade-off between performance and memory. To get better performance, you need to use more memory, and to save more memory, you need to need to use more CPU cycles. I'll be discussing three Memory Reduction Categories: - Optionality, both build-time and runtime. Optionality is about providing options so you can get rid of the stuff you don't need and include the stuff you do need. - Tunability, which is about providing options so you can tune your application by trading performance for size, and vice-versa. - Efficiency, which is about balancing size savings with performance.

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