How to name my brick?

[esmetaman]

Hi,

I am testing new NXJ release, I would like to create a general Class to manage communications between 2 nxt brick.

My first doubt is:

how to name my brick? In javadoc, I saw the method: setFriendlyName(byte[] name) but how to convert a string into byte.

For example:

I would like to change the name of my brick, for example: "NXTBOT1" how to convert this string into a byte[] format?

Thanks

[bbagnall]

There's a tool with NXJ that lets you change the name of your brick. It's called NXJBrowse and it's located in the directory lejos_nxj/bin. I think it will only change the name under USB for now. Under Bluetooth it might look like it changed the name but it actually doesn't, if I'm not mistaken.

[esmetaman]

Hi brian,

I will test with nxjbrowse, but with the method setFriendlyName, is it possible?

I have found a way to make a class to convert string to byte[]

Thanks.

[esmetaman]

Hi Brian,

I tested nxjbrowse, but i received a exception in my MSDOS console:

C:\DATOS\ROBOTICS\NXJ\samples\jab\1>nxjbrowse
found 5 busses
#
# An unexpected error has been detected by HotSpot Virtual Machine:
#
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x6d07baf4, pid=3536, ti
#
# Java VM: Java HotSpot(TM) Client VM (1.5.0_09-b01 mixed mode, sharing)
# Problematic frame:
# C [awt.dll+0xbaf4]
#
# An error report file with more information is saved as hs_err_pid3536.l
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#

C:\DATOS\ROBOTICS\NXJ\samples\jab\1>

Can you tell me the cause?

[lawrie]

You should be able to call Bluetooth.setFriendlyName directly, e.g:

String nameString = "NXTBOT1";

byte[] nameBytes = new byte[16];

for(int i=0;i<nameString.length();i++) nameBytes[i] = (byte) nameString.charAt(i);

nameBytes[nameString.length()] = 0;

Bluetooth.setFriendlyName(nameBytes);

I don't know why nxjbrowse caused a JVM failure. Does this happen immediately, or when you change the name? Did it happen with the 0.3 release also?

[esmetaman]

Hi Lawrie, I tried to test NXJBROWSE command using MSDOS console and a typed NXJBROWSE, and I received this exception.

I will try your code.

Why do you defined a byte array with 16 elements?

Thanks

[esmetaman]

Thanks Lawrie, I understood your code.

My idea is run a class and it used new features using LCUID.

import lejos.nxt.*;
import javax.microedition.lcdui.*;
import lejos.nxt.comm.*;

public class BotNamer{

public static void main(String[] args)throws Exception {

/*
LCDUI obj = new LCDUI();
String texto = obj.show();
*/
String NXTName = "SOLDIER1";
Graphics gObj = new Graphics();
gObj.drawString(NXTName, 0, 0);
gObj.refresh();
setNXTName(NXTName);
}

static void setNXTName(String NXTName){
int size = (NXTName.length()+1)*2;

byte[] nameBytes = new byte[size];

for(int i=0;i<NXTName.length();i++){
nameBytes[i] = (byte) NXTName.charAt(i);
}
nameBytes[NXTName.length()] = 0;

Bluetooth.setFriendlyName(nameBytes);
}
}

I can receive data from TextBox Object. Anybody can I help me?

import java.util.Random;

import javax.microedition.lcdui.*;
import lejos.nxt.*;
import java.util.*;

public class LCDUI implements CommandListener{

private TextBox input;
private Display display;

private static final int CMDID_BACK_TO_MAIN = 1;
private static final int CMDID_EXIT_APP = 2;

private static final Command BACK_COMMAND = new Command(CMDID_BACK_TO_MAIN, Command.BACK, 0);
private static final Command EXIT_COMMAND = new Command(CMDID_EXIT_APP, Command.STOP, 2);

public void LCDUI(){

}

public String show(){
TextBox input = new TextBox("Enter NXT Name:", "", 10, TextField.ANY);
input.addCommand(BACK_COMMAND);
input.setCommandListener(this);

Display display = Display.getDisplay();
display.setCurrent(input);
display.show(true);

return input.getText();
}

public void commandAction(Command c, Displayable d) {
if (c.getCommandId() == CMDID_BACK_TO_MAIN) {
Display display = Display.getDisplay();
display.quit();
}
}

}

I tried to modify original sample, But I dont know how to transfer a String from the execution of LCDUI class

My original idea is deliver a NXJ tool to define the NXT BRICK using new Textbox Class

[lawrie]

The protocol between the ARM chip and the BC4 chip sends the name as 16-bytes padded out with zeroes. The code in the LCP class that calls setFriendlyName passes a 16-byte array. I think setFriendlyname currently only works if it passed the full 16 bytes. I will fix this for the next release.

I will look at your code for setting the name from a TextBox if I get the chance. I have not looked at the LCDUI code much yet. It was written by Andre Nijholt.

[esmetaman]

Write to my personal email to send Andre Nijhol's email to contact with him.

Thanks.

[lawrie]

I do not have Andre Nijholt's email address - I think Brian has it.

The program below works for me for changing the name of the NXT.

I am not sure if what I have done is correct, but it seems to work, apart from, for some reason, you have to press ENTER twice to select the SetName text box.


import javax.microedition.lcdui.*;
import lejos.nxt.comm.*;
/**
*
* @author Lawrie Griffiths
*/
public class SetName implements CommandListener {
private static final int CMDID_BACK_TO_MAIN = 1;
private static final int CMDID_EXIT_APP = 2;

private static final Command BACK_COMMAND = new Command(CMDID_BACK_TO_MAIN, Command.BACK, 0);
private static final Command EXIT_COMMAND = new Command(CMDID_EXIT_APP, Command.STOP, 2);

private List menu = new List("Set Name", Choice.IMPLICIT);
private Ticker ticker = new Ticker("Tools");
private TextBox input = new TextBox("Enter Name:", "", 16, TextField.ANY);
private Alert exitAlert = new Alert("Exit");
private Display display;

/**
* Start application
*
* @param polling Select method for button handling
*/
public void startApp(boolean polling) {
// Create main menu
menu = new List("Tools", Choice.IMPLICIT);
menu.append("Set Name", null);

menu.setSelectedIndex(0, true);
menu.addCommand(EXIT_COMMAND);
menu.setCommandListener(this);
menu.setTicker(ticker);

// Set textbox properties
input.addCommand(BACK_COMMAND);
input.setCommandListener(this);

// Start displaying main menu and handling buttons
display = Display.getDisplay();
display.setCurrent(menu);
display.show(polling);
}

/**
* Handle events.
*/
public void commandAction(Command c, Displayable d) {
if (c.getCommandId() == CMDID_BACK_TO_MAIN) {

if (d == input) {
// Name has changed
String nameString = input.getText();
byte [] nameBytes = new byte[16];
for(int i=0;i<nameString.length();i++) {
nameBytes[i] = (byte) nameString.charAt(i);
}
Bluetooth.setFriendlyName(nameBytes);
}
// Display main menu again
display.setCurrent(menu);
} else if (c.getCommandId() == CMDID_EXIT_APP) {
// Request to exit application
exitAlert.setType(Alert.ALERT_TYPE_CONFIRMATION);
exitAlert.setString("Exit Lejos?");
exitAlert.setCommandListener(this);
display.setCurrent(exitAlert);
} else {
// Handle system commands
if (d == exitAlert) {
if (exitAlert.getConfirmation()) {
display.quit();
} else {
display.setCurrent(menu);
}
} else if (d == menu) {
List list = (List) display.getCurrent();
if (list.getSelectedIndex() == 0) {
display.setCurrent(input);
}
}
}
}

public static void main(String[] args) {
new SetName().startApp(true);
}
}