I'm writing an application that needs access to a serial port (it's a credit card reader). I'd like to be able to read and write to the port. The following seems like it would let me do exactly that: http://www.activexperts.com/serial-port-component/howto/html/. However, this deals with ActiveX/COM which means I'm tied to Windows.
Any better solutions for me? Would be nice if the solution would work on multiple platforms, not just Windows.
I'm using PHP.
Does the device emulate a keyboard? You'd be much better off getting the user to position the cursor inside a textbox (or putting the cursor there programmatically) and swiping the card if that's the case.
I spent a lot of time writing a userspace driver in C for a Magtek Mini-Mag card reader only to realize years later that it was academic more than anything. I mean we used the code, only if we'd have gone with the keyboard solution there would have been tons of time to focus on other things.
For the Mini-Mag the USB/HID support in the kernel would recognize the device, hopefully there's something similar for the device you're getting.
Also, Windows has it's own variant of USB/HID so the 'treat it as a keyboard' solution works pretty much out of the box for devices that act that way.
Related
I have very old Siemens CX70 in working state and just don't want to throw it out. My idea is to use its math power and peripherals (GSM module, USB, Camera and screen) to build some simple applications for home use (multichannel termometer, timer and cheap security system - for examples).
I know I should use Java ME and IDE (I love Netbeans, for example). Can you tell me what I need more to start developing? I know Java well, I just need to make an environment to developing, debug and deploy. Mobile library documentation will be very helpful too.
Thanks.
There are so many online tutorials about this topic that the only right thing to do is to refer you to google.com
Search after "getting started with j2me".
However, there's something else you should know upfront before getting too excited.
The security model in JavaME will prevent you from doing much useful stuff, in relation to some of the things you mention.
Every time you try to access certain things in the phone, like e.g. the camera, or send SMS, or read/write a file on SD card, etc etc - the phone will show a popup "This app is trying to access camera. Allow this?". And the app will only continue after a manual click on Yes.
As you can imagine, this of course renders a lot of ideas useless.
In order to prevent these popups, you can sign your app with a certificate you buy from Thawte or Verisign. But as that'll cost you $300 a year, it's not the way most sparetime hobby developers chooses.
Personally, I found another way, but it requires you to use a phone from Sony Ericsson.
Because the old Sony Ericsson phones can be patched in order to remove the Java security. After doing this on one of my old phones, I've been having fun making apps like the ones you mention. For example, an app that keeps an eye on my home when we're out, by taking a picture every second. If it detects a difference in the picture, it sends me an MMS with the picture. :-)
I have searched a long time for patching options for other brands, but I just can't find anything useful. Nokia should supposedly also be patchable, but I just can't find anything useful about it.
So in short: If you'd like to make some sparetime hobby apps on a phone like that, you should either find a Sony Ericsson phone and patch it - or go dig up an old used Android device.
Good luck.
I am talking about components that can be externally attached to a computer system via some port or other means, not about any of the component that is part of or peripheral of computer itself.
Actually, working on a college project for controlling traffic lights and boom barrier at railway crossing. I've got knowledge in Java but I do not know how can I get the traffic lights and boom barrier working on events in a Swing based application?
One thing is I can create a electronic circuit which can read the small output voltages at computer ports such as a USB port and used them as a trigger for controlling the devices. But how can I generate that small voltages using Java application?
Is JavaPOS can be the solution? or something else?
Any ideas? Suggestions? Articles? Samples?
I'd work backwards from the external device. Answer this 1st: What's the easiest way to communicate with it? If you say USB, ok, use usb. Then ask, what's the easiest way to interface with USB. Then build in whatever language you find to be easiest this USB interface. Finally, call from your Java swing application to this USB-wrapping application... it could be that simple invoke the app using something like ProcessBuilder.
In other words, I think it might be a mistake to solve the problem of interfacing to something like this device with Java, unless it's easy to do so directly.
Have you considered communicating with these external devices by sending digital signals to a serial port using Java? It's then a simple matter of either using those digital signals directly, or using an Analog-to-digital converter to get a voltage of desirable magnitude.
Same for input from the serial port. The RXTX library can help you do this (communicate with the serial port).
On the other hand, if you have access to MATLAB, then this sort of stuff is a piece of cake. Take a look at the Data Acquisition Toolbox and Instrument Control Toolbox.
I think your looking at this the wrong way. Most lights are them selves computer controlled. The lights are running on a computer system. If your project is to write this start to end, then you need to write a loaded to the light controller that does many things, one controls light color and direction, also allow connections via an out side computer. This connection could be USB, Ethernet ext. Now write a program facilitating connecting to the lights and pass commands to the light controller.
I'm doing some work for my theses in networking, and have stumbled into a little problem. One of the first steps in the work I must do consists on having a computer working as an AP (I am using hostapd for this) and with it, detect all the devices in the room which currently have wifi turned on (do not need to be associated with any AP).
I have found a thread that pretty much asks the same ( discover mobil devices using wifi ), and I understand the answers that were given, but they don't give any hint as to how this can be done. The post ends saying that the person was able to do this using Kismet, however I can only seem to use Kismet to discover clients already associated with an AP.
Can someone point me in the right direction here please? If not using Kismet, then maybe suggest a different tool that works with Ubuntu.
Ps. I will need to run a continuous scan of the "room" to find any new devices and then send this information to an event manager written in Java.
I guess you could have a WiFi card, in monitor mode, scanning every channel for beacons. On Linux, aircrack-ng is the tool suite you are looking for. airodump-ng is the tool that shows you a list of devices present around your location. It is designed to display first the hotspots with the potentials clients, but also shows all the devices that are connected to an AP or trying to probe to an AP.
However, you won't be able to scan devices having their WiFi connection turned down. I'm not sure about devices not associated to an AP, my guess is you will be able to detect them if they send beacons one way or another (for example, to detect WiFi hotspots).
If you need this in Java, you can write a wrapper to airodump-ng, or you can launch airodump-ng as a service outputing to a file and read this file from a Java app.
No concrete answer I'm afraid, but I hope these will help you figure a way to solve your problem.
I am looking to create a video training program which records videos - via webcam, user screen capture and captures sound. Now the main problem is that I need a cross-platform (mac and windows) solutions.
I know its possible to use flash to record webcam + audio. But its not possible to record the user's screen via flash.
So am wonder if I should use Java (which i believe will work on mac & windows). I do not want to develop to separate versions because of the cost involved in developing two versions.
Please guide me as I am new to this.
Thank you.
UPDATE
Hello again,
I had a look at the following site: www.screencast-o-matic.com or www.screentoaster.com. I see that they have developed a java applet which helps interact with Windows/Mac to record the screen.
I am wondering how to go about developing something like that and integrating it with Flash (for webcam and audio recording).
Is this a better idea?
This is not an answer to your question, but I strongly recommend against using video for educational programmes. Our company delivers university courses on-line, and we long ago learned that video feeds are only effective under particular scenarios. In general, a talking head is a waste of bandwidth. You're much better off to put together a well designed powerpoint presentation, record a voice-over (and edit it!) and then assemble the whole thing as a flash presentation. This is a non-trivial amount of work, but it provides a much more interesting product for the student.
When to use video:
1) When you are demonstrating something dynamic - Mechanics or Chemistry for example.
2) When you are acting out a scenario or case as an illustration -- For example, threat de-escalation techniques for high school teachers.
When you solve the screen recording problem, seriously consider whether you need full motion or if you can get away with stills. Often the motion is distracting, and a still with good voice over can be more effective. (Hint: Replace mouse pointers with something HUGE before recording -- Like Fox did with hockey pucks)
Try CamStudio. I don't know, if it works on Mac, but on windows, it's the best solution I know. It's open source, so you can use it's source code, if you want to :)
If you're looking to build an application that does all of the recording and screen capture itself, then you might consider using Adobe AIR (essentially, Flash running on the desktop) in combination with Merapi. Merapi is essentially a bridge between Adobe AIR and Java. So for example, for your project, you might use Java to handle the lower-level (but still cross-platform) stuff you can't do natively in AIR, and use Merapi to wire the Java application to your AIR UI.
This is by no means a simple project. Lets get that said and out the way. There are open source (and cross-platform) options for each element, but nothing (I know of) that will do everything for you.
I think the "cleanest" option would be to use Flash for webcam and audio, as you said, and run a VNC server to send the screen video... The only closed-platform code will be the VNC launching code. That should be pretty simple to maintain!
That raises a problem because most people are behind NAT firewalls these days. Setting up port forwarding is a pain in the behind. I've used an app called Gitso before which allows people to connect to me and send their desktop to my screen (for tech support). Its VNC-based and all it really does is add another layer on top of the VNC connection so rather than me connecting to them, they connect to me. That makes the whole business of port forwarding a non-issue.
And once you've recorded everything, there's the final issue of syncing it all back together... Might not be so hard.
Well, Camtasia provides the solution to get your problem done. It can record the onscreen activity and also the webcam video and put them in the same player template. Another screen recorder DemoCreator can publish the screen recording as Flash movie, but can not record the webcam.
is it possible to create java application that will
work as background process on symbian smartphones?
You can approximate it but J2ME (the version of java on mobile phones) may not be the right technology to do this.
starting a MIDlet (a Java application for mobile phones) when the phone is switched on is tricky at best without coding a small Symbian OS C++ module that will start it for you. If you want to try anyway, look at the PushRegistry class in the MIDP specs
(http://java.sun.com/javame/reference/apis/jsr118/). The Content Handling API might provide some way to do it too (http://java.sun.com/javame/reference/apis/jsr211). When you are ready to give up, do it in C++.
Backgrounding a MIDlet isn't hard. The phone's "menu" key will do it for you. Programatically, Canvas.setCurrent(null) has a good chance of working. Trying to trick the phone by providing a fully transparent GUI and not handling any keypad activity will absolutely not work. Creating and starting a separate Thread in the MIDlet should allow you to keep something running even after your overload of MIDlet.pauseApp() has been called by the application management system.
The real issue is that the MIDlet will not have any Inter Process Communication system unless you make one. The usual way of doing that is a loopback socket connection over which you transfer data. Not a nice or efficient way of simulating IPC. Sharing a RMS record can only be done from within the same MIDlet suite (you can package several MIDlets into the same .jar file), I think. The code to create a provider/consumer data flow over a file connection is even uglier and will raise security issues.
Without any more information about what you want to use it for, my answer is : maybe but you should probably not try.
You will have in-built MIDP support for background MIDlets in MIDP 3.0 (http://jcp.org/en/jsr/detail?id=271). Don't hold your breath for devices to appear, however - might be some time.
(Note that a few Symbian OS devices have more than just MIDP - the S-E p990 for instance, https://developer.sonyericsson.com/site/global/products/phonegallery/p990/p_p990.jsp).
As already pointed out, it might be helpful to have more information on what product functionality you are trying to implement - often more than one way to skin a cat.