| Design Basics |
| Bruce's Design Rules |
When is a design good enough? How do you know you are starting the design process or architecting a system
appropriately? These rules should help. |
| Why Should I Use Java? |
Java is neither perfect nor magical. It's an object-oriented computer language built on the syntax of
C. Java happens to be a very well-designed, current-technology language, with a lot to recommend it. Java also includes a
suite of "helper tools" such as javadoc and jar. Assuming you understand its strengths and can apply
it
appropriately, it help you create better (more robust, easier to use and maintain) programs in less time than other languages. |
| Java Fundamentals |
Classes, methods, fields, objects, packages, Java primitives, etc. If you are new to Java, or coming from the C or C++
world, start here to get the big picture. |
| Abstract classes and interfaces |
Commonly used to write I/O drivers or define APIs for use by others |
| Why and how to document your code |
Code which is not well documented is neither understandable nor usable, yet such code is (lamentably) common. Stop wasting
your (and others) time and start properly documenting all your code (not just Java). |
| Some accepted Coding Standards |
Make your code readable and understandable by using accepted structure and naming conventions. Standards also enable a
company or team to produce code which is consistent and maintainable. |
| Java Tools - General |
| Java Tools List |
How to set up your Java development environment from scratch. Here's a list
of what to get and how/where to get it. |
| Java Tools Installation |
Once you have the various tools files, here's how to install and configure them. |
| javaxcomm debugging help |
Send in your war stories and we'll add them to ours. |
| Understanding Java paths |
What, exactly, happens when you invoke "java.exe" on your PC? What if you have
multiple JSDKs and JREs installed? How do you reference one set of development and
runtime libraries such as javaxcomm? |
| Java Tools: Tools within the J2SE SDK |
The J2SE SDK is the heart of any Java development tool set. This includes java,
javac, javap, javadoc, jar, and more. |
| Javadoc |
|
| Java Tools: Ant |
How to use Ant to automate Java builds |
| Java Tools: Ant Tips |
Ant can be a bit frustrating to figure out. These tips may save you some headaches. |
| Java Tools - NetBeans |
| The
NetBeans IDE |
Netbeans 6 is worth a look even if you are a strong
fan of Eclipse, especially if you have need of its special features
such as tight SunSPOT and phoneME integration. |
| Java Tools - JStamp/JStik/Saje (using aJile controller) |
| Current aJile upgrades |
Here's how to install aJile runtime and tool upgrades |
JemBuilder Tips |
JemBuilder is the linker for aJile targets such as JStamp/JStik/SaJe. It combines your
class files with runtime support libraries, and creates a file which can be executed
by the target hardware. There is no formal documentation or online help for JemBuilder
since aJile didn't feel any is needed. Here are some tips and advice which may help
you understand and use this tool. |
| Charade byte-code
debugger (coming soon) |
Charade is the debugger for aJile targets such as JStamp/JStik/SaJe. It is a byte-code,
not a java-source debugger. It's not the easiest thing to use. Here are some helpful
tips. |
| Projects which don't fit anywhere
else |
| Sony Ericsson K850i |
A very decent little camera (actually two cameras with
three modes), music player, and superb Java support. Oh, and it's
also a phone. |
| Help with some practical issues - serial I/O, threading,
etc |
| Helpful Utilities package - com.systronix.util |
We all seem to need the same simple helper classes - programmable time delays, hexadecimal
conversion, various ways to blink an I/O pin, etc. So we have created the com.systronix.util
class as
a place
to put all these odds and ends. |
| I/O: Using UARTs with javaxcomm |
javax.comm is the standard Java package for parallel and serial I/O. All "real Java" embedded
systems support javax.comm for serial I/O, and systems such as the PC support parallel I/O
too. All we use is the serial portion of javax.comm. |
| I/O: Amulet LCD and touchscreen |
Here's the easiest way to create a Graphical User Interface (GUI) for embedded systems,
using a 1/4 VGA monochrome LCD and touchscreen. |
| Threading: generic threads |
Generic Java threads include the class java.lang.Thread and some methods in
java.lang.Object |
| Threading: periodic threads |
JStamp, JStik and SaJe support real-time, periodic threads |
| Help Getting Started with JStamp,
JStik and SaJe from Vitus Bering Institute |
Vitus Bering Institute is a technical school in Denmark. The Real
Time Java group there is led by Hans
Sondergaard. Bruce Boyes of Systronix met
them in fall 2003 at the JAOO conference. |
| Periodic Thread tutorial at Vitus
Bering. Applies to JStamp,
JStik and SaJe. |
Hans Sondergaard and his students have probably done more study of Periodic Thread than
any of our customers. Here's a page of help from their web site. |
| Writing your own aJile Interrupt Service Routine |
The existing event handler framework has some overhead which can make response to slow.
So, rather than use the general purpose framework, here's how to write your own, faster,
specific-purpose interrupt handler. |
 2006 Feb 21 - Rebooting JStamp/JStik/SaJe
(aJile-based systems) from your application: aJileReboot application
note. |
Sometimes you'd like to change some configuration in your application, or load a new
one using the bootloader, and cause a firmware reboot to start up in the new application.
Here's how to do the reboot part of that. This app note does not describe how to write
or use a bootloader, which is a non-trivial issue in itself. |
| Interfacing |
| All
about SPI |
The Serial Peripheral Interface (SPI) is a high speed (as fast as 20 MBits
or more, depending on the hardware). JStamp and JStik can burst SPI at about 4 and
6 MBits, respectively. TStik and TINI390 can bit-bang SPI at bursts of 500 Kbits or
so. |
| I2C |
I2C is a slower peripheral bus than SPI, but it has some low-cost
and interesting devices. These principles also apply to the "TWI" (Two Wire Interface) used on the Atmel AVR controllers. |
| Benchmarks |
| Embedded
Java Benchmarks |
"Figures don't lie, but liars can figure", and the same is true of benchmarks.
Still, they can be useful,, which is why we all still use them. Here are some which we have
run on a variety of embedded Java systems. We also include the source code and raw results files
so that you can run and analyze them yourself. |
| Tutorials - start here with Blink |
| Blink Tutorial Level One |
A simple Blink example with all the source code in one Java file,
no need to use external libraries, etc. |
| Blink Tutorial Level Two |
A more complex Blink which uses an external library and System
properties |
| Blink Tutorial Level Three |
Blink one or more pins using a Thread object for each Blink instance |
| Blink Tutorial Level Four |
Blink one or more pins using a custom event handler
object |
| Blink Tutorial Level Five |
Blinks multiple pins using (real-time) PeriodicThread objects and
the new Systronix RealTime thread scheduler. |
| Blink Tutorial - Morse code |
Blink the JStamp, SaJe or JStik heartbeat LED with Morse code messages.
You could also drive a speaker for Morse code tones. |
|