Bluetooth Client Program To Communicate With Micro Controller
Jan 30, 2014
I use a bluetooth module (dwengo) in combination with a microcontroller (PIC16F877A). I want write a bluetooth client program in java to communicate with the microcontoller. Examples of clients on internet do not work or give errors I cant'n resolve. There is one program ( SampleSPPClient ) that give no errors and shows the bluetooth devices present.
But when I choose my bluetooth module I got an error (Device does not support Simple SPP Service). I think that I have to use an other service of bluetooth but I don't know how to implement. Here is the program I tried to use ....
Im trying to write a java program to search nearby bluetooth devices.. Im using Bluecove-glp-2.1.0 and bluecove 2.1.0..Im working on Ubuntu 13.04 LTS.I typend a code to get the local Device name..
public class BluetoothSearch { public static void main(String[] args) { LocalDevice ld= null ; String name = ld.getBluetoothAddress(); System.out.print(name); } }
this is my code.. It returns me null. doesn't return me the local Device.
This is what the gui looks like at run time. The question is how do I compact it so there is not so much space between the labels and the textArea. I've tried using different numbers on my GridLayout, but not a lot of success.
I have the following code which reads in data from a bluetooth transmitter, however the program is crashing upon read-in. The bluetooth connects to the device just fine, as indicated by the indicator LED on the transmitter. However during the read-in:
void beginListenForData()
is where the exception happens. Specifically, it is at the line
readBuffer[readBufferPosition++] = b;
However I don't know why it is crashing. My transmitter is sending 1 byte (0x02) at 9600 baud every 1 sec for testing purposes.
I have an application written in Java on the Linux platform. My application will work the following way:
User A will open application. User B will open application.User A will need to send User B a message but without a socket connection.User B will need to send User A a message but without a socket connection.The user should be able to identify the messages sent to each other.If User A reads user B's message the message will no longer be available in the channel of communication.If one user exits their application their message should be removed.User C should not be able to read user A and user B message (This is only via the application design, no real security here).Applications should be able to work on different machines however they will utilize a shared network mount to access files modified by each other.
I do have to note that the messages being sent is rather small and only 1 message is sent from each user, so in that regard I did not want to setup a client/server model to do this using sockets.
Basically I am looking for a similar concept as a message queue but more relevant to my requirements done in Java. What are some good options to use that will address some of my requirements? I have not touched Java in a long time and only have used it for certain usage so I am trying to get an idea of which current technologies are best for what I need.
I have to develop a code in parallel which is implemented in sequential yet. How to add the server client relation in the program so that work can be divided into multiple clients.
So i wrote this text to try and create a simple chat program that does the following: Prepend names to messages, announce entrance and exit of chat, display user list, and share a whiteboard.So far the Server seems to be working but the Chat Client is throwing errors at me left and right..
CURRENT ERROR: Microsoft Windows [Version 6.1.7601] Copyright (c) 2009 Microsoft Corporation. All rights reserved.
C:Windowssystem32>cd.. C:Windows>cd.. C:>Usersjaydesktopchat 'Usersjaydesktopchat' is not recognized as an internal or external command, operable program or batch file.
I've been provided a code skeleton for what must be done, but despite my best efforts to make things work, I'm coming up dry (obviously, due to a lack of knowledge.) One thing that might work is if I knew how to debug this type of application, line-by-line, to see exactly what is going on. Obviously, it's easy enough to debug the client part, but moving over to the server part, I haven't been able to figure that out (I'm using Eclipse.)
I am currently writing two java classes (client and server). The client takes an input number form keyboard and sends it to the server. The server then multiplies this number by two and sends it back to the client. The numbers should also be printed to screen along the way, for example if I input the number 3 I should get
"From Client: 3" "From Server: 6"
They should continuously do this unless a negative number is received by the client, say for example the number -3 is sent to the server and it returns -6.
The code I have for the two classes so far is:
import java.io.*; import java.net.*; import java.nio.ByteBuffer; import java.util.Scanner; class Client { public static void main(String args[]) throws Exception { DatagramSocket clientSocket = new DatagramSocket();
[Code] .....
Currently, when I run the program all I get is an output of the number first entered. I am aware it requires a loop but I don't know where and what the condition should be.
Also if I wanted to adapt this so that it would take the integer from client and subtract two at the server and return to client who sends back to server to keep subtracting two unless it reaches a negative number at which point the client will terminate the program - how might I do this.
I do realise there needs to be a while loop in the above code, but I wanted to test it sent the number from client to server and its not doing it. All I get is a print screen of 'enter number' and then the number I enter.
I had some questions about a theoretical java program. Say you had a java program on a linux server/pc that referenced a folder on that server. And say you had a Client PC (Windows) that had a share folder to that java program.
If that windows client PC tried to run the program would it run (with a GUI if it had one) and would the main directory of the java program still be on the linux server or would it be on the windows computer since that is the computer that is running the program?
Basically I have a program I am trying to find the best way to run it remotely on a windows computer but it references files on the linux server it is located at and needs to put files it creates there as well. I am just trying to make sure I understand my theory here on how the program will run if it IS run remotely.
My overall goal is to create a server that can receive a message from a client and send an automatic reply in captial letters..As well as having the incoming messages decoded to display the header information..The server also needs to save a log of incoming and outgoing commutations..The client needs to be able to attacha text or JPG file and be able to coummucnate with the client.Okay this is what i have so far
I really need them to be able to communicate with each other with messages i am struggling making that work as so far they can talk only to themselves the message aren't getting sent between them, let alone adding the other feutures.
I have tried each and every thing in all the other answers. Like setting chunked to false, changing parameters, changing http1.1 -1.0. I am just writing a sample client to compare it with my real time client. Following is the code of client:
package com.webservicemart.ws; import java.rmi.RemoteException; import org.apache.axis2.AxisFault; import com.webservicemart.ws.USZipStub.ValidateZip; public class UsZipClient { public static void main(String[] args) {
[Code] ....
And Following is the error :
[INFO] Unable to sendViaPost to url[http://www.webservicemart.com/uszip.asmx] org.apache.axis2.AxisFault: Transport error: 404 Error: Not Found at org.apache.axis2.transport.http.HTTPSender.handleResponse(HTTPSender.java:310) at org.apache.axis2.transport.http.HTTPSender.sendViaPost(HTTPSender.java:194) at org.apache.axis2.transport.http.HTTPSender.send(HTTPSender.java:75)
[Code] ....
I have tried with other geoIP service and weather forecast too. I get the same error.
Me and my brother decided to make a relatively simple client/server program where clients get into a simple chat lobby and can invite others to play small games(like pong). The basic server code has been written, and we have made a special client that is used for debugging.
We use a self-defined protocol of Strings where a message looks like "4-|user,pass". The number before the delimiter "-|" is the operation code, that tells the server what kind of message this client sends. Based on that number, the server dispatches the message to the appropriate handler method. 4 is authentication for example, and the handler looks the user and pass up in a file and if found, returns true, otherwise, false. Then the server responds to the clinet with 2-|"any message" where the client will recognize opcode 2 as a "authentication accepted" and proceed with the next part of client code. In a similar way, we plan to write all message types(both in the game, in the lobby and in a game setup room).
While testing we ran into a problem where the BufferedReader .readLine() does not seem to be a blocking call like it should be, so the client keeps spamming 'null' in the output field that we made to see the server response to the message we send. When we try to debug the server code and set breakpoints at the suspicious locations, it strangely skips both while(true) loops without activating either breakpoint and executes the finally{} code, even though the client did not close the connection and the second while loop was never entered. The first while loop IS entered though, because the test client gets a "0" on its output, which is the server message indicating "please authenticate yourself".
We decided to use messages in a string format and decode it at both sides as it seemed easier than transmitting java objects and making sure they are of the same type, also for reducing overhead as much of possible.URL....
Model View Controller design pattern I completely understand then I was told about the observer controller pattern. After reading and reading I and watching video clips on youtube explaining it I have a question:
Isn't the actionListener the observer so to speak. It is firing whatever action it is told to do and dynamically updates the program to.
Example, I have a JButtons and a JTextArea. I press the button and it gives the current stock price of some stock, I press it again it refreshes. Sounds like an observer to me... Am i on the right track here?
create an application following the MVC pattern. My frame is composed of a JTable with some JComboBox and classic next/previous buttons to page the table. The table shows data of current accounts of the members of a family. My problem is figuring out how the controller interacts with the view, for example to enable / disable buttons or reset and reload the data in the comboboxes. In the view class all the graphical components are private instance variables. What is the best approach to ensure that the controller can act on them?
I need to create in the view public methods to act on each component like getSelectedItemAccountCombo, getSelectedItemYearsCombo, getSelectedItemMonthCombo, populateAccountCombo (ArrayList <String> list), setNextButton (boolean b) ... and so on (I think that the methods would be many ...) This approach does not convince me because I think that the class is fouled by procedures that should be in the controller class.
I am unable to connect my javafx scene to mysql database. I get a java.lang.NullPointerException every time. I tried searching everywhere possible but no answers available. This is the Person class (super class for Teacher class):
/* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */
I have used jsp's to passing request to the servlet or controllers. but we can also pass request from javascript using ajax and sending data using json.
what is the good approach and why? or does it depends on the situations? is yes, what kind of situations?
I do Java for decades, but am a FXML beginner. Currently I do FXMLLoader.load(fxmlFile) in Application.start(), which is working well. My Application instance is creating a background thread in Application.init() which feeds several custom application properties with incoming data taken from a remote model (wrapping a sensor hardware). Some of my windows shall later be able to access those properties. So the question is: How can I inject my Application instance into the FXMLLoader-created controller instances auto-bound to the FXML-created Scene instances?
I used the SceneBuilder to create an applications and it works quite well. Now I got a problem to set the pref. size of a ScrollPane to the size of the app.
I want to install a binding between the scroll pane's pref. size and the stage's pref. size. Since the scroll pane field reside in the FXMLController class I need a way to access this field.
I am working on an project in which some data needs to be received through socket , do some processing on it and then store on the database. After that it will display on GUI. GUI should be updated automatically.
I am able to implement basic model in which data is storing in the database and displayed then on the GUI. I tried to implement MVC design patter as well.
Now i need to create a GUI which can be used by several users at a time means several jvm session for the GUI. I got struck at this point.
Some detail: i have one jvm session in which i am receiving , processing and storing the data. Now i want to fire an alert whenever any new entry is made into the database. Also each time new GUI is opened it should be registered with the model so that model send updated data alert to all this users.
When i am trying to open several GUI and trying to register with the Model then it is not increasing count of registered user. For each time it is showing 1 count only and whenever a new entry is made count is showing 0. Is it because both are running in different jvm sessions ?
Some code for the model which is running in different package and jvm
GUI..
private void runApp() { //some gui code WindowListenerClass windowListener = new WindowListenerClass(this); frame.addWindowListener(windowListener) //registering viewer with the model Model.setNewAlarmEvent(this); tableModel = windowListener.getDefaultTableModel();
When I hit the url at the first time my call goes to the spring controller and sets the userDetails objects in the modelAndView.addObject("userDetails", userDetails.getUserDetails()) and returns the userDetails.html page. if I click any link in the same page i want to pass same (userDetails) object thru javascript or jquery and calls the another(controller) method and returns the same (userDetails.html) page.
It means how can I pass the java object thru javascript or jquery and calls the controller. If I get the same object in my controller i can avoid calling the db again.
