I add some detail to my question. I receive on my Xbee device a flow of GPS coordinates but I'm unable to read and stock these data on a buffer. My Xbee device is connected to my laptop on a usb serial port, that's why I want to create a program java to read and use my data flow sending by the serial port. I'm searching on internet some code example or tutorials, without enought advices for my understanding, or I just find some dead projects.

USB to serial chip CH340 English DataSheet. CH340 is a USB bus convert chip and it can realize USB convert to serial interface, USB convert to IrDA infrared or USB convert to printer interface. In serial interface mode, CH340 supplies common MODEM liaison signal, used to enlarge. Java Rxtx Usb Serial Converter. The class codes of the device interface descriptors should be used to identify which drivers are supported by the device. In practice, these are hardware registers ports in the computer. USB has effectively replaced a variety of earlier interfaces, such as serial and parallel ports.

I found that it's possible to use jssc library or javax.comm (but I can't download the javax.zip on sun). Do you know an other better USB API?

Could you help me to understand how I can manage to read and stock my Flow of GPS cordinate? Forget abut USB, it acts as transparent bridge. What you need is a way to read from the serial port. Javax.comm is not (officially) available any more. I have been successfull dealing with the arduino serial port with the library. First make sure you see the serial port on your dev machine. This might require to install a driver.

Then use a terminal program to connect to the serial port. Once this is working go on and get RXTX working. Download paint tool sai full version free english. Just in case: You can have only one connection at a time. Make sure that only one of IDE, terminal programm and RXTX is connecting to the serial port at the same time.

[Paul] wrote in to tell us about some interesting he helped nail down and fix on the Arduino. It seems that [Michu] was having some problems with controlling his we featured earlier this year, and he couldn’t quite figure out why he was experiencing such huge delays when sending and receiving data. Searching online for answers turned up very little, and since [Michu] was using Processing, the pair designed a set of tests to see what kind of latency was being introduced by Java. Pitting an Arduino Uno and an Arduino from 2009 against a Teensy 2.0, the tests gauged the latency of native data transfers versus transfers facilitated by Java via the rxtx library it uses for serial communications. The results were pretty stunning. While both of the Arduinos lagged behind the Teensy by a long shot, their latency values under Java were always 20ms at a minimum – something didn’t add up. [Michu] poked around in the rxtx code and found a mystery 20ms delay programmed into the serial library.

It made no sense to him, so he changed the delay to 2ms and saw a drastic increase in performance when transferring less than 128 bytes of data. The pair’s fix doesn’t seem to affect latency when larger amounts of data (>1kB) are being transferred, but it makes a world of difference when manipulating smaller chunks of data. For the sake of disclosure, it should be noted that [Paul’s] company produces the Teensy mcu. • • • • Posted in Tagged,,,,, Post navigation.

This could not have come at a better time. I have been fighting a serial issue that I could not track down for a a few days this week. I never thought to look into the library, since it is such a basic function I assumed it should be solved. I have mixed feelings about the “easiness” of the arduino or similar platforms.

It seems like I get to a prototype faster, but the “more difficult” C or other development systems prove much easier to augment or debug and the development time ends up being a wash. Very often serial recieve rutines do work with a buffer eg. Like above 128bytes If it’s fulll you will get a data recieved interupt and nobody think on this. If you recieve less than the buffer size there will be a timeout like above 20mS so if you do look for only a few bytes then reduce the buffer size or see if it’s posible to check for every RX chr It’s the same problem when you use a USB to RS232 adaptor on a PC the USB do typical tx when it’s buffer are full like 2k data or when a time out ocours that’s why it stinks if you like to eg. Controll a CNC or something timedepending Wiljan. Hi, Paul here who wrote the native benchmark Michu wrote the Java stuff and did most of the legwork on this project, so he really deserves most of the credit for all these results. Anti-Java rhetoric is really misplaced.