I want to use Java applications in an embedded hardware

Question

I have to design a new hardware with a uP (not determined yet) to run JavaME applications. I've searched information about how do it, but for the moment it has been useless.

Can anyone explain how I can do it?

From what I found in my search: - Using a uP (ARM for example) with an OS (ie: Linux) (using JIT for better performance) - Using a uP with Jazelle. Do I have to use also an OS???

The application is an alarm control system, so it doesn't need graphical interface. Minimal requirements are: ethernet port, 2 UARTs, SPI bus, I2C bus, min 16MB ram, min 4MB rom, IO ports.

Any suggest?

Regards, Juanma

Answer 1

Since you are using JAVA application, I guess ARM926EJ (with Jazelle core) might be helpful.

What I am not sure is, why would you need a Java application for an alarm controller?

Anyway,

• Step-1: Decide on the microcontroller (ARM with Jazelle) seems to be a good bet, considering the large number of tool chains and eval boards already available
• Step-2: Based on your requirement decide on an eval board from a vendor. Most likely, the vendor will also give you, the schematic, ported embedded linux version with the associated drivers
• Step-3: On top of the embedded Linux write your application
• Step-4: Check the final RAM and ROM size after you finish developing the application
• Step-5: Modify the schematics and design your own hardware

This is normally how we develop embedded hardware ...

Answer 2

Based on your question, here is what I believe are your requirements:

• New embedded computer system
• Runs Java Micro Edition applications

Question:

• Do you know what Java ME configurations and profiles you need to support: CDC, CLDC, MIDP and to which version? (you say no GUI, so MIDP may not be required.)

Recommendations:

• Don't try to develop your own PCB and software simultaneously. Find an embedded hardware system that has your needed peripherals and use that.
• Preferably, find an embedded hardware system that comes with a royalty-free POSIX firmware layer.
• Do NOT pursue Jazelle. It would be a lot of work for something you may not need. If you're running Java ME without MIDP, your performance will be satisfactory.

Answer 3

Good luck comes to mind. Embedded platforms can be a huge pain to develop from the ground up. Also most off-the-self micro controllers share their SPI bus with many devices making it only useful for quick short messages (don't plan on doing much else with the ethernet if you try to do webservices). I have not used any of the devices below but they looks like they might point you in the right direction.

• http://www.systronix.com/
• http://en.wikipedia.org/wiki/Sun_SPOT
• http://www.is2t.com/en/index.php
• http://www.parallax.com/tabid/517/List/0/CategoryID/13/Level/a/Default.aspx

Answer 4

ARM's Jazelle page certainly implies that an underlying OS supporting Jazelle is needed. This HOW-TO article on embedded.com may help clarify things.