I2C with Java?

[Romek]

I've found a handful of libraries around which enable me to access the GPIO pins in Java, but is there anything around for the I2C? I've been searching around for quite a while now, so any help would be appreciated. Thanks in advance!

[xranby]

I think the easiest way to access I2C with Java is by first load the i2c-dev Linux kernel module

Code: Select all

sudo modprobe i2c-dev

This Linux kernel module will setup files in /dev/i2c-* that maps to all attached i2c devices.

To access these files from java you need to be able to issue linux specific "ioctl" calls, the most straight forward way to do it is by connecting Java to the system "c" library that contains the ioctl function call using JNA:
Take a look at the sourcecode to purejavacomm this file show how to map the "c" library using JNA in order to give Java applications access to "ioctl".
https://github.com/nyholku/purejavacomm ... l.java#L63

Finally you need to have the Linux kernel documentation in hand that describe how to use the /dev/i2c-* files
http://www.kernel.org/doc/Documentation ... -interface

[ianm1981]

I would also love to get this working. I've got things running ok in python and I managed to get the rxtx libraries working on java I think but the basic listAllPorts() demo code they supply lists nothing so I can only guess <wild speculation>that the libraries cant find the Rpis hardware. </wild speculation>

If anyone could shed some light on this or show a successful implementation of i2c in java It would be really useful for me.

[xranby]

Peter "rotok" have built a working #raspi #java #linux #i2c binding using #JNA.
http://www.raspberrypi.org/phpBB3/viewt ... 73#p187073

[pccourt]

http://pi4j.com has I2C support.