Friday Apr 26, 2013

BeagleBone Black: Great Raspberry Pi competitor and runs Java SE Embedded

Step right up! For only $45, you can get an awesome BeagleBone Black Linux/ARM, Sitara AM335x 1GHz ARM Cortex-A8 processor, 512MB DDR3 RAM, and 2GB of eMMC memory. Wow! Now, that's giving the RPi a run for it's money! And... it can run Java SE Embedded. That's the coolest part...

See:

BeagleBone Black $45

Here's a quote:

 Out of the box, the BeagleBone Black 
 includes a single DC power barrel
 connector, two USB 2.0 ports (one 
 micro USB), a micro SD card slot, a 
 micro HDMI port for video output, and 
 a 10/100 Ethernet jack (internally 
 USB, just like the Raspberry Pi). In 
 addition to the somewhat-standard 
 PC/mobile IO options, the BeagleBone 
 Black has two 46-pin connectors on 
 either side of the PCB that can 
 accept cape expansion cards...
Only 45 bucks. Nice. Think of all the Java Embedded apps you can run on that... :-)

Thursday Apr 11, 2013

Last chance! A few good embedded submissions needed for JavaOne

Roger Brinkley is making a plea for a few good embedded abstracts for the JavaOne 2013 call for papers which is still open until Fri. 12Apr2013.

See:

A Few Good Talks

Here's a quote:

 The JavaOne 2013 Call for Papers closes 
 April 12, but [Roger Brinkley is] still 
 looking for a few good Embedded Java talks
Go here JavaOne 2013 Call for Papers and submit your idea today! You CAN handle the truth!

Thursday Apr 04, 2013

RPi with an Oscilloscope and Java Embedded: Ready for Benchmarking (Part 7)

Meh. I'm only getting 22KHz (see photo) with this last approach using java.io.FileWriter on the GPIO file handle. That's much slower than the Pi4J Java to JNI library from Savage Home Automation. And, no where close to the 5MHz using C native.

It might be better to continue to debug the NIO memory mapped buffer that I was originally thinking should be as fast as C native. I was getting "No device found" error when trying to map the /dev/mem of the Raspberry Pi. So, it might have something to do with the /dev/mem not actually looking like a file to the java.nio APIs.

I'll start adding some debug lines to my NIO code next to see if I can narrow down the issue. Meanwhile, I'll also try taking out the flush() calls and see if I can eke out a bit more speed from the java.io.FileWriter approach...

/*
 * Example Code
 */
      // Set up a GPIO port as a command channel
      FileWriter commandChannel = new 
        FileWriter("/sys/class/gpio/gpio" +
        GpioChannels[0] + "/value");
            
      // Loop forever with fastest on/off to GPIO pin
      while (true) {
         commandChannel.write(GPIO_ON);
         //commandChannel.flush();               

         commandChannel.write(GPIO_OFF);
         //commandChannel.flush();        
         }
       } 

More details as I figure out the NIO error message...

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Hinkmond Wong's blog on making Machine to Machine (M2M) and the Incredible Internet of Things (IoT) smarter with Java Embedded Technologies

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