Problem on installing jUART plugin in Linux-Ubuntu

Hi to all,

I have to install a plugin (jUART-plugin) to get weighing machine value in both WINDOWS & LINUX. File is in there https://github.com/billhsu/jUART.
I got installed successfully in windows using following instructions:

But I can't install npjUART.so (jUART Plugin) in linux. I have latest version of firefox in linux.

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Install Plugin Instruction:
Windows:

Copy the /bin/Windows/npjUART.dll into your browser's plugin directory.

Take FireFox for example: Copy /bin/Windows/npjUART.dll to C:\Program Files (x86)\Mozilla Firefox\plugins

Linux:

Copy the ./bin/Linux/npjUART.so into your browser's plugin directory.

Take FireFox for example:

sudo cp npjUART.so ~/.mozilla/plugins/
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I have tried some other ways too apart from above in linux such as 

$HOME/.mozilla/plugins
program_directory/plugins
/usr/lib/mozilla/plugins
/usr/lib/xulrunner/plugins 

Still I didn't get active jUART plugin.
At which flavour of linux it will be worked..? Here I have tried with ubuntu.
 
Is there any way to get that plugin on firefox in linux?
 
 
Thanks & Regards,

Suriya...