Cant find I2CFactory and I2CDevice

[RonaldTHerman]

I have pi4j 2.7.1 library. I'm looking to

import com.pi4j.io.i2c.I2CDevice;
import com.pi4j.io.i2c.I2CFactory;

But it cant find them but it does find

import com.pi4j.io.i2c.I2CBus

What am I missing?

[taartspi]

https://www.pi4j.com/documentation/io-examples/i2c/.

Maybe look at this example to see what imports are relevant to i2c in V2. It is a simple example easy to code up. Not all those imports are needed in v2. With mention of factory are you migrating from pi4j V1 ? Tom

[RonaldTHerman]

I'm trying to write a byte to an I2C device that has no registers.. The example that I was trying to use apparently was written for an older pi4J.. How do I do the follow with v2.7 of pi4j?

`
// Get the I2C bus
bus = I2CFactory.getInstance(i2cBusNumber); <== no I2CFactory
// Get the I2C device
I2Device device = bus.getDevice(deviceAddress); <== no I2CDevice

// Data to write (example: a single byte)
byte dataToWrite = (byte) 0xAA;

// Write the data to the device
device.write(dataToWrite);
`

[taartspi]

I think those basic steps are in the example i listed

PS. You mentioned your device does not use registers

So you would use tca9534Dev.write(currentState);

[taartspi]

I created a new file in intellij and pasted the contents of SimpleTca9534I2cTest and it compiles as is.

(I2C tca9534Dev = i2CProvider.create(i2cConfig)

this line ? It is an instance of the I2C interface

`Interface I2C

All Superinterfaces:
AutoCloseable , Describable, I2CRegisterDataReader, I2CRegisterDataReaderWriter, I2CRegisterDataWriter, Identity, IO<I2C, I2CConfig, I2CProvider>, IODataReader, IODataWriter, Lifecycle, Readable
All Known Implementing Classes:
I2CBase

public interface I2Cextends IO<I2C, I2CConfig, I2CProvider>, IODataWriter, IODataReader, I2CRegisterDataReaderWriter, AutoCloseable
I2C I/ O Interface for Pi4J I2C Bus/ Device Communications
.`

[RonaldTHerman]

Thanks, I’ll check it out tomorrow. Bed time here.

[RonaldTHerman]

I renamed the .so file.
mv pi4j-library-linuxfs-armhf.so libpi4j-linuxfs.so

These are the files in my lib directory for linux
-rw-r--r-- 1 pi pi 48670 Jul 25 15:00 pi4j-plugin-linuxfs.jar
-rw-r--r-- 1 pi pi 33029 Jul 25 15:00 pi4j-library-linuxfs.jar
-rw-r--r-- 1 pi pi 8976 Jul 25 15:00 libpi4j-linuxfs.so

So what is this? (sorry about the font.. `` or <> doesn't help)

OpenJDK Server VM warning: You have loaded library /home/pi/NetBeansProjects/RelayBoardTest/dist/lib/libpi4j-linuxfs.so which might have disabled stack guard. The VM will try to fix the stack guard now.
It's highly recommended that you fix the library with 'execstack -c ', or link it with '-z noexecstack'.

A fatal error has been detected by the Java Runtime Environment:

SIGSEGV (0xb) at pc=0xf7e27ba0, pid=16331, tid=16338

JRE version: OpenJDK Runtime Environment (11.0.27+6) (build 11.0.27+6-post-Raspbian-1deb11u1)

Java VM: OpenJDK Server VM (11.0.27+6-post-Raspbian-1deb11u1, mixed mode, g1 gc, linux-)

Problematic frame:

C [ld-linux-armhf.so.3+0xcba0]

No core dump will be written. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again

An error report file with more information is saved as:

/home/pi/NetBeansProjects/RelayBoardTest/hs_err_pid16331.log

If you would like to submit a bug report, please visit:

Unknown

/home/pi/bin/relaytest: line 16: 16330 Aborted sudo -E java -Dlog4j.ConfigurationFile=File:$DIST/log4j2.xml -Dpi4j.library.path=$LIB -Djava.library.path=$LIB -jar $DIST/RelayBoardTest.jar

[taartspi]

I use maven and intellij on the Pi for my work. I do not think any file (so) mv is required

https://github.com/Pi4J/pi4j-maven-archetype I saw netbeans in those details. I am not familiar using it for pi4j and cannot speak to that environment. The link in this response has details about its use and setup.

Does this mean you successfully compiled that example code and now are trying to deploy it?

[RonaldTHerman]

I don’t see how netbeans has anything to do with it. I run that on macOS where I do the build and editing. Then netbeans sends (ssh) to the Rpi. I’ve had to put the .so files in the library directory because the app wasn’t finding them. I had to rename the armhf so file for the same reason.

Actually your example boils down to what I was originally doing with Pigpio. That didn’t work so I looked for an example and ended up with the one the used Factory and Device. That was pi4j v1.0 code. I’m running 2.7.1

Supposedly the .so files get extracted from their .jar files at run time but that doesn’t seem ever to happen.

[RonaldTHerman]

Got things working with i2c.write(0xFF) without linux files... I tried this first time but must have had a loose wire.. Thanks for your patience.

[RonaldTHerman]

problem solved

[taartspi]

Hey Ron. Glad you got it going