Unofficial FLL FAQ06-c - NXTG
UFAQ Table of Contents
Q14.1) Can we use the NXT-G programing language with out RCX robot?
The NXT-G language does not work with RCX robots. RIS or Robolab are the languages that wil work with RCX.
Q14.2) We have run out of memory. What can we do?
A1) Rethink your programming approach. This is especially true for veteran RCX teams. With the highly flexible motor move icons, what you were forced to do in several icons, can now be done in one. Re think your programming style to match the new capabilities.
A2) Do not use sounds in your programs. Although it is great fun to have your robot squeal like R2D2, it is a monumental waste of memory.
A3) Do not use graphics in your programs. Graphics are not as bad as sounds, but they provide little benefit to an FLL team in comparison to the amount of memory they consume.
A4) Minimize the number of programs you have. Each time you use a motor icon in a new program it takes 5.0K. Subsequent uses of the motor icon take as little as 4 tenths of a K. Therefore combining your missions into as few programs as possible can be very helpful.
A5) Use the memory management features to delete out old unused programs. Having programs you are not using just wastes critical memory space.
A6) Delete out non critical system files. When delivered from the factory or after a firmware update, the NXT is loaded with lots of files and programs that you may not need. In this condition you have about 68K of memory. Deleting these can buy you back a considerable amount of memory. To do so, start up NXTG and open a file to be able to access the NXT Window dialog box. Use the more robust USB connection for this delicate operation.
- Click on the Memory file tab and then check on the “Show System Files” checkbox.
- Although there is a “Delete All” button, it only deletes all the programs you have loaded on the brick. We will need to visit each section and delete files individually.
- Starting at the bottom with “Program” you can safely delete the Demo program.
- Click on Sounds and delete all the files. You will loose the sounds the NXT makes on bootup and key presses.
- Click on Graphics and delete all the files. You will loose the smiley face on the LCD screen.
- Click on Other and delete the files NVConfig.sys and RPGReady.sys. This will remove the interactive “NXT Program” programming via the front panel.
- Now delete the Try- files. This will save a large chunk of memory at the expense of being able to use the “Try-me” functionality from the front panel.
- At this point you should not have any files left on your NXT and it should show about 130K free or nearly double what you started with.
Q14.3) Are MyBlocks soubroutines? Will they save us program space?
A) MyBlocks are true subroutines, and you can nest them quite deep (I regularly use them 2-3 layers deep already).
The important thing from a memory standpoint is that a MyBlock in a program is only stored on the NXT once, no
matter how many times it's used, or in what places within a single program. This can be a tremendous memory saver.
Furthermore, from the standpoint of teaching, it provides a drive to get the kids to modularize their programs far
more than Robolab or RIS did.
There is a downside - it means that two parallel sequences trying to use the same MyBlock at the same time won't
work very smoothly (one sequence will have to "wait" until the other sequence releases the MyBlock).
UFAQ Table of Contents
Disclaimer: This FAQ is not an official FIRST document.
It is an accumulation of knowledge derived from six thousand messages posted to
the FLL forum over three seasons. It has been reviewed by numerous people, but may
still contain errors. Use at your own risk.
Readers are encouraged to submit errors, suggested wording changes, new topics,
or comments to Skye Sweeney at email@example.com
Copyright 2003-2006 Skye Sweeney; Last Updated on 10/28/2006