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2.1 Mobile Information Device
Profile
MIDP profile specifies Connection Limited Device
Configuration (CLDC) for use in smallest devices,
like usual mobile phones. Just this platform pleases
largest focus, because it is concerned in a body of
extensive devices. The MIDP profile adds to
hardware specifications a minimum requirement on
display size (96 x 54 pixels) and the possibility to
control device by character keyboard or by screen
touching. It also requires at least 8 kB stable
memory for saving data application. In version
MIDP 2.0, whose specification is already available,
important functionality is improved, like interface by
sockets or sound control. Practically each of mobile
phones belongs to MIDP category. Application for
this category is called midlet according to basic class
of MIDP profile.
3 JAVA AND LINUX ON PDA
IPAQ
The most common variant is using Linux on
classical Pocket PC. Since Pocket PC’s are in most
cases on purchase already equipped with Windows
CE system, it is necessary to replace it with desired
Linux distribution. This is user's exacting operation
requiring higher knowledge level in the area of
installation and system repair. There are now
multiple projects focussed on development of Linux
implementations for the iPAQ, including one from
the Hewlett-Packard sponsoring handhelds.org site.
In particular, this Familiar Project provides
comprehensive free and open support for the iPAQ.
3.1 HP iPAQ platform
HP iPAQ 5450
The iPAQ 5450 model has a 240 x 320 pixel backlit
colour LCD screen and is powered by a 400MHz
Intel Strong-Arm processor with 64MB of RAM and
64MB of flash memory. This device has integrated
support for wireless solutions as Wi-Fi, Bluetooth
and infra red.
On this model of iPAQ we have installed a
Familiar Linux distribution on which is running
JVM needed for SCADA application. We use HP
iPAQ H4150 on which is running WM2003
operating system to tests created applications.
HP iPAQ 4150
HP iPAQ 4150 is classical PDA from Hewlett-
Packard too. It has the same parameters as 5450
model. Only flash memory (NAND flash) is smaller
in compare with.
This system is equipped by WM2003, and a
special virtual machine J9 from IBM Company.
3.2 WebSphere Everyplace - J9 VM
If we want to work with an application written in
Java, we have to install Java runtime Environment
(JRE). JRE includes JVM, which is typed and
compiled for existent platform, respective concrete
processor of given Pocket PC, how it was already
described above.
The J9 VM is the core of WebSphere Everyplace
Micro Environment (WEME), the IBM
implementation of the JVM Specification, Version
1.3.
The J9 VM and Java Class Libraries (JCL)
comprise the J9 runtime environment. The J9
runtime environment is J2ME compliant and
contains CLDC and CDC based technologies. In
addition, the WebSphere Everyplace Custom
Environment (WECE) is a combination of the J9
VM and IBM custom libraries.
The WEME product is supported on a variety of:
• Operating systems (including Microsoft
Windows, Linux, PalmOS, OSE, Rex,
VxWorks, PocketPC, Symbian, QNX and
Nucleus)
• Hardware architectures (including Intel x86,
xScale. ARM, MIPS, SH4, and PowerPC)
On J9 VM we can run application created for mobile
phone under MIDP specification without any change
of source code. Developer must create only one
product in one specification and it is runnable on
PDA, mobile phone or on other embedded device
with running J9 VM.
Space required to install J9 VM is:
• J2ME Mobile Information Device Next
Generation (JSR-118) MIDP 2.0 – 3MB
• J2ME Personal Profile 1.0 (JSR-62) – 8MB
4 SCADA
SCADA stands for Supervisory Control And Data
Acquisition. As the name indicates, it is not a full
control system, but it rather focuses on the
supervisory level. As such, it is a purely software
package that is positioned on top of hardware to
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