MojoLoader RXTXcomm on Fedora linux

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johan
Posts: 3
Joined: January 3rd, 2014, 5:28 pm

MojoLoader RXTXcomm on Fedora linux

Post by johan » January 3rd, 2014, 6:05 pm

Not a question, but might be helpful to others encountering similar issues.

On Fedora the Mojo USB connection is created at port /dev/ttyACM0 (in my case)
In order to access /dev/ttyACM0 the user needs to be part of the 'dialup' group.
This change was not enough to make the loader stay alive when selecting a port.

The MojoLoader distributed in mojo-loader-1.1.2-linux64.tgz tries to create 'lock' files to regulate port usage.
Fedora does not allow lock files to be created at the location that is used.
I tried the following workaround:
- install package rxtx from the repositories
This package is configured to write locks in the appropriate location (performed by native librxtxSerial.so)
But unfortunately the java RXTXcomm.jar is programmed only to present /dev/ttyS* devices as available (this is the default behavior of the java code in the RXTX project).

I assume the sources of RXTXcomm.jar where modified to also show /dev/ttyACM* devices.
As a workaround I mixed both distributions and replaced the librxtxSerial.so as delivered in the mojo-loader with the library from the Fedora package.
(overwrite the existing library in mojo/lib with the version in /usr/lib64/rxtx/librxtxSerial.so)
This works, but shows a warning about mixing the java code of one version with the native library of the other (smart code).

Hope this helps someone, because it took me a night figuring this one out.

Tinkerer
Posts: 7
Joined: October 5th, 2014, 1:34 pm

Re: MojoLoader RXTXcomm on Fedora linux

Post by Tinkerer » October 5th, 2014, 2:08 pm

Thanks! This was just the bit of info I needed!

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