LEJOS vs Original Firmware

This is where you talk about the NXJ software itself, installation issues, and programming talk.

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LEJOS vs Original Firmware

Postby spideyfly » Wed May 30, 2007 2:09 am

Hi all,

I'm new to LEJOS, however I would like to know whether the LEJOS NXJ firmware uses the original firmware as a base in any way? Is it a completely separate implementation? Does it mimic the behaviour of the original? What does it do differently?

Thanks in advance for your time :)


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Postby Hardrive » Thu May 31, 2007 7:26 pm

I don't know what it is based off of.

However, it is completely different. For one, there is no menu system. You can't store your programs directly onto your brick.

This means that your NXT has to be in "reset mode" whenever you want to run a program.

However, correct me if I'm wrong, you get more space available for programs, the programs run faster, AND, most importantly, you can program in Java.

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Postby takashic » Fri Jun 01, 2007 1:14 pm

I think LEJOS team has made their original work.
However, I guess that they had used LEGO Mindstorms NXT Hardware Developer Kit as the reference, and an ARM7 expert implemented LEGO equivalent functionality.
While I was hacking LEJOS firmware to make LEJOS OSEK, I found a funny difference between LEJOS firmware and LEGO original one in I2C communication. According to the Hardware Developer Kit, communication rate for I2C is 380kHz and LEJOS uses this, however, actually LEGO firmware uses 400kHz. So LEGO might change the rate after the release of the Kit.

My general impression on both firmware was, LEJOS firmware is developed by an embedded control software expert and LEGO firmware is more UI driven software. Anyway, both are great!

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Postby imaqine » Fri Jun 01, 2007 2:44 pm

leJOS was built on top of TinyVM. With that being said, I am pretty sure TinyVM was built from the bottom up. TinyVM is no longer used but if you want more information take a look at its website http://tinyvm.sourceforge.net/

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Postby bbagnall » Sat Jun 02, 2007 2:23 pm

Hi Spideyfly,

The current release is just an Alpha tech demo for those who were keen to play around with it. Our next release will be the first relatively complete release, which includes a working menu system, file system, FLASH memory storage, and multiple program uploads. I wouldn't base too much of an opinion on the current release.

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Postby spideyfly » Tue Jun 05, 2007 4:07 pm

Thanks all for the replies. I have been trying to compare the different programming alternatives for the NXT to see which one was most expandable for addons and things...sorta like what takeshic has done with LEJOS-OSEK :)


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