Java serial communication


USB serial is available on nearly all Arduino based boards. Further, there are serial interface Java libraries that can connect to an Arduino. If you are unfamiliar with data communications in general, take a look a the introduction to data communications article ; although it does not cover serial communication, it is still a good starting point for the unfamiliar.

For an out the box complete solution checkout our new BETA library tcMenu library for Arduino including remote control. TcMenu not only provides a full menu system with designer, but also remote control from Arduino to Java using RS or Ethernet.

Take note of the ports used for the various connectors as they will be needed to set up the sketch later.

Serial Communication in Java with Example Program

Note that this script uses PWM contrast based on the link above. Now wire the switches in as well, each switch should be wired to the board as per the example circuit on the left never use less that a 4k7 resistor for this or the current drain will increase.

java serial communication

At 4k7 the current drain for each switch when on is about 1mA; which is not particurly high even with a few switches normally on. At this point you should have both the 20x4 display and a few switches connected according the circuit above.

Now is the time to load the code onto the Arduino device. In the script there are some changes that need to be made, in order to tell the script where to expect the LCD display and also the buttons.

Once everything is wired up, you will need to enter the pins used for the display and switches noted earlier into the sketch.

Change the constants at the top of the sketch as shown in the example below using your own settings. In my example I had the buttons connected on bins Now we configure the serial communication speed, I set it to be baud but over USB, it can reliably run faster. As long as all is wired up correctly you should be able to run the script on your Arduino, the display should initialise and look like the example below.

If not, switch off and check your wiring and code carefully.

Serial port access using JAVA of Pi - - Raspberry Pi #9

The PWM contrast setting can be adjusted in the setup section of the script. There are several examples contained within the code, you want to look in the com.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information.

Can someone recommend one to me that they've tried or knows about that is easy to implement on Windows XP? I started looking for the same thing couple weeks ago, and I've been very happy with the multi-platform RXTX library so far.

Has a very clean, easy to understand API. Without reservation, I recommend Java Serial Port from serialio. They support the standard Java serial API, as well as their own alternative proprietary one. I would stick with the standard API though, unless you really need something theirs has that the standard one doesn't, just to keep your options open. I've been using PureJavaComm for the last five years or so.

It's actively maintained, and is a pure Java via JNA implementation. RXTX has let me down because of a lack of maintenance and numerous subtle problems. Personally, I'd stick with SerialIO because it is supported and actively worked on. RXTX, not so much. I've written an open-source Java library because none of the existing ones fit my needs outdated, closed-source, hard to modify, un-maintained, Currently only supports Windows, but I have plans for supporting Linux.

You can easily modify the native part with the latest Visual Studio if you need. Learn more. Asked 11 years, 5 months ago. Active 3 years, 11 months ago. Viewed 42k times.

How communicate with serial port in Java ?

Steve Steve 1, 7 7 gold badges 26 26 silver badges 30 30 bronze badges. Active Oldest Votes. Murat Ayfer Murat Ayfer 3, 6 6 gold badges 24 24 silver badges 26 26 bronze badges. The quality of the RXTX code is quite bad. Be prepared to jump through various hoops if you go down this road.

I'm running into issues on USB comm ports under abnormal circumstances e. Lawrence Dol Lawrence Dol Jason S Jason S k gold badges silver badges bronze badges. This library instantly won me over because there are no platform-specific native libraries to bundle with the distributed app!

Martin Naskovski Martin Naskovski 31 2 2 bronze badges. All with a full GUI showing real-time activity on the ports.

Arduino to PC communication using USB serial and Java

I agree. SerialIO Serial Port is inexpensive, it support multiple platforms and you get the source code. Thibaut D. The Overflow Blog.Because of Java's platform-independence, serial interfacing is difficult. Serial interfacing requires a standardized API with platform-specific implementations, which is difficult for Java. Unfortunately, Sun didn't pay much attention to serial communication in Java.

Sun provided a reference implementation for a few, but not all Java platforms. Particularly, at the end of Sun silently withdrew JavaComm support for Windows.

Third party implementations for some of the omitted platforms are available. JavaComm hasn't seen much in the way of maintenance activities, only the bare minimum maintenance is performed by Sun, except that Sun apparently responded to pressure from buyers of their own Sun Ray thin clients and adapted JavaComm to this platform while dropping Windows support.

This situation, and the fact that Sun originally did not provide a JavaComm implementation for Linux starting inthey now do led to the development of the free-software RxTx library. RxTx is available for a number of platforms, not only Linux. It can be used in conjunction with JavaComm RxTx providing the hardware-specific driversor it can be used stand-alone.

JCL is part of the RxTx distribution. Sun's negligence of JavaComm and JavaComm' s particular programming model gained JavaComm the reputation of being unusable. RxTx - if not used as a JavaComm driver - provides a richer interface, but one which is not standardized. RxTx supports more platforms than the existing JavaComm implementations.

Recently, RxTx has been adopted to provide the same interface as JavaCommonly that the package names don't match Sun's package names. So, which of the libraries should one use in an application?

If maximum portability for some value of "maximum" is desired, then JavaComm is a good choice. If there is no JavaComm implementation for a particular platform available, but an RxTx implementation is, then RxTx could be used as a driver on that platform for JavaComm. This way the application doesn't need to be changed, and can work against just one interface, the standardized JavaComm interface.

This module discusses both JavaComm and RxTx. It mainly focuses on demonstrating concepts, not ready-to-run code. Those who want to blindly copy code are referred to the sample code that comes with the packages. Those who want to know what they are doing might find some useful information in this module.

There is also another library called jSerialComm t hat includes all its platform specific files in its jar, this makes it truly portable as there is no installation necessary. It is highly recommended to follow the installation instructions word-for-word.

If they say that a jar file or a shared library has to go into a particular directory, then this is meant seriously! If the instructions say that a particular file or device needs to have a specific ownership or access rights, this is also meant seriously. Many installation troubles simply come from not following the instructions precisely. It should especially be noted that some versions of JavaComm come with two installation instructions.

One for Java 1. Using the wrong one will result in a non-working installation. In such a case the corresponding source code distribution of RxTx needs to be obtained, which should contain complete instructions. It should be further noticed that it is also typical for Windows JDK installations to come with up to three VMs, and thus three extension directories.

JavaComm is notorious, because it requires a file called javax. Sun constantly refuses to correct this error, citing the mechanism is essential. Which is, they are lying through their teeth when it comes to JavaCommparticular, because Java for a long time has a service provider architecture exactly intended for such purposes. The contents of the properties file is typically just one line, the name of the java class with the native driver, e.

The following is a hack which allows to deploy JavaComm via Web Start ignoring that brain-dead properties file. It has serious drawbacks, and might fail with newer JavaComm releases - should Sun ever come around and make a new version.

First, turn off the security manager.This is more of a follow-up to my previous post about serial programming in Java here and how to install the RXTX libraries here. I wrote an example program that includes all of those steps in it and are each in their own separate method within the class, but first I will go through my hardware set up. User input is given from the PC through the a Java GUI that contains code for serial communication, which is the code presented here.

The Arduino is responsible for reading this data. This set up is pretty much using my computer as a remote control for whatever device is on the Arduino end.

It could be a motor control, on-off switch, etc. However, I did create a GUI for testing purposes. See the Code Downloads section for the actual files. Above is the picture of the GUI complete with the buttons that I use to interact with the program. I also added key bindings which I can use to control the throttle. When the program is first started, none of the GUI elements will work except for the combo box and the connect button.

Once a successful connection is made the controls are enabled. This is done through the use of the setConnected true and the toggleControls methods shown in the example code that follows. Depending on the Java IDE it might already know to tell you to use these imports except for the first one. I named my class Communicatorbut the name is really up to the programmer. The name pretty much reflects its intended use.

The class should also implement the SerialPortEventListener class. This is a class in RXTX and is required in order to receive incoming data. This method will be defined later. Below are the variables and constants that I defined in my class. What the variables are for is in the comments but a more detailed explanation will follow. The GUI class extends javax. What that means is that I can associate put method the name of a serial port, say a string that says COM1, to an object in the code.

Later, I can access the name COM1 from the HashMap by using the get method and it will return the object that it was associated with previously. The CommPortIdentifiers object is needed to gather the list of ports that are available for connection. The SerialPort object is for storing the data for the port once a successful connection is made.

The InputStream and OutputStream is the object that is required for sending and receiving data. The constants for the ASCII values are some values that I use to send through the output stream that act as delimiters for data.

The string logText is basically what the comment says. When stuff happens in the program, the program stores a string in this variable and it will be appended to a text area in the GUI. The method below is for searching for available serial ports on the computer. The method getPortIdentifiers returns an Enumeration of all the comm ports on the computer. The code can iterate through each element inside the Enumeration and determine whether or not it is a serial port.

The method getPortType can identify what kind of port it is. If it is a serial port, then the code will add its name to a combo box in the GUI so that users can pick what port to connect to. The serial port that is found should also be mapped to the HashMap so we can identify the object later. This is helpful because the names listed in the combo box are the actual names of the object COM1, COM2, etcand so we can use these names to identify the actual object they are tied to. The method below is for connecting to the serial port once they have been found see previous section.

Using the HashMap we can retrieve the CommPortIdentifier object from the string that was mapped earlier. The object must also be casted as a CommPortIdentifier because the get method has a return type of Object.The Java Communications a. This API may be used to write terminal emulation software, fax software, smart-card reader software, and so on. Developing good software usually means having some clearly defined interfaces. The high-level diagram of the API interface layers are shown in this figure.

In this article we will show you how to use javax. We'll also discuss what the javax. We'll present a small example program that shows you how to communicate to the serial port using this API.

At the end of the article we'll briefly detail how this javax. Unlike classical drivers, which come with their own models of communication of asynchronous events, the javax. Let's say we want to know if there is any new data sitting on the input buffer.

We can find that out in two ways -- by polling or listening. With polling, the processor checks the buffer periodically to see if there is any new data in the buffer. With listening, the processor waits for an event to occur in the form of new data in the input buffer.

As soon as new data arrives in the buffer, it sends a notification or event to the processor. Among the various serial interfaces available, two of the most popular are the RSC and RS standards, which define the electrical signal levels and the meaning of various signal lines. Low-speed serial interfaces typically clock data out as a square wave, with clock coordination provided by start and stop bits.

RS stands for Recommend Standard ; the C simply refers to the latest revision of the standard. The serial ports on most computers use a subset of the RSC standard. The full RSC standard specifies a pin "D" connector, of which 22 pins are used. Most of these pins are not needed for normal PC communications, and indeed, most new PCs are equipped with male D-type connectors having only 9 pins. For more on RS, see the Resources section.

This is available free on the Internet. Please see the Resources section for more information. A complete API specification for serial and parallel communication ports. In this article we consider serial ports only. Without a common API in your development efforts, workload will increase because you'll have to provide support to serial devices.

Normally, in RS, there are two signal lines and the rest are intended for control lines. Depending on the type of communication synchronous or asynchronousthe number of control lines selected may vary. This API provides access to the underlying control signals. A brief diversion here may help you understand something about parity and start and stop bits.

Parity was added to RS because communication lines can be noisy. Let's say we send ASCII 0which in hex equals 0x30 or in binarybut along the way someone passes by holding a magnet, causing one of the bits to change.I remember back in Freshman year, worked on a wireless board for my Intro to Engineering project. Back then, not knowing anything really from programming, I decided that it would be cool to make a wireless remote game controller like the Wii controller.

The TA tried to help but it was hopeless, lol. Anyway, did a bit of coding today and this is what I got after messing around for couple hours. Most time was spent trying to get Arduino to send the data out correctly. Will probably write a Java Class for it to make it even easier to use.

This is the easiest one I found, so I decided to mess around with this one first.

java serial communication

After installing the library in Netbeans by adding the jssc. Posted below are the source codes I used in my messing around. So hardware-wise, just hook the Arduino to your computer through a USB. You can only have one program use the port at a time. Arduino to Java Serial Communication 2. But I assume this method of converting everything to String is pretty novice, lol.

I should just get a starter set of random stuff and play with it lol. It is consistent, portable, efficient, reliable, testable, extensible, modifiable, scalable library. You are commenting using your WordPress. You are commenting using your Google account. You are commenting using your Twitter account. You are commenting using your Facebook account. Notify me of new comments via email.

java serial communication

Notify me of new posts via email. Then I did it again with the Space Hopper project, if I only know how to read Joystick data in Java… Anyway, did a bit of coding today and this is what I got after messing around for couple hours. SerialPort; import jssc. SerialPortList; import jssc. Share this: Twitter Facebook.

Like this: Like LoadingMost projects that deal with hardware and devices, needs to communicate with them using the COM port of the PC or Server. For example if there is a modem that is connected to a server via its COM port and the Java program has to read the output of the modem then the Java program has to read the COM port for any incoming data.

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[Engineering] Arduino to Java Serial Communication

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