Solved

usb communicatioons

Posted on 2012-03-17
8
286 Views
Last Modified: 2012-03-17
I would like to write a java routine to send and receive from a usb port.  I have been looking at several sites and it appears to more than a trivial task.  I did run into this response to the question on a site and am curious about the statement concerning mounting it and writing to it like a drive.  Anyone have any insite on this approach and maybe a little explanation as to how to do it?

The following is the posting from the other site:

if you are looking to directly build something in low level you can see http://www.beyondlogic.org/ for information about specs...

If you want some examples of code you can look at http://www.libusb.org/wiki/libusb-1.0 ... It's in C though.

If you just want to communicate with the USB in linux, you can just have linux mount it and write to it as a regular drive without having to deal with all the other stuff...
0
Comment
Question by:sargent240
  • 5
  • 3
8 Comments
 
LVL 83

Accepted Solution

by:
Dave Baldwin earned 500 total points
ID: 37733777
USB is a network interface, not just a port.  Most devices require low level drivers.  Generally speaking, I don't believe java is suited to that.  So for most devices, you need to talk to the driver and not the USB 'port'.  If it 'looks' like a disk drive to Linux, you can address it that way.
0
 

Author Comment

by:sargent240
ID: 37733782
Your saying it does not look like a disk drive, right?
0
 

Author Comment

by:sargent240
ID: 37733785
I'm trying to control a music keyboard with a computer and can do it with the rs232 port.  When I plug in the usb to midi cable "midi1" appears in the dev directory.
0
 

Author Comment

by:sargent240
ID: 37733802
Can you tell me what value there is in the "midi1" entry in the /dev directory when I plug in the usb to midi cable if any?
0
Efficient way to get backups off site to Azure

This user guide provides instructions on how to deploy and configure both a StoneFly Scale Out NAS Enterprise Cloud Drive virtual machine and Veeam Cloud Connect in the Microsoft Azure Cloud.

 
LVL 83

Expert Comment

by:Dave Baldwin
ID: 37733816
I suggest you try to send your data to the 'midi1' device like you would a file.  That would be standard practice in Linux.  Open, read, write.  You should get the same responses as from your RS-232 version I would think.  Just a different interface.
0
 

Author Closing Comment

by:sargent240
ID: 37733864
Again Thanks.
0
 

Author Comment

by:sargent240
ID: 37733875
I have one other question and I will open a new question if you like, but how is the baud rate controlled if it is handled like a file?
0
 
LVL 83

Expert Comment

by:Dave Baldwin
ID: 37733976
Midi only operates at 31.5 kBaud as far as I know.  You don't have to set it for a USB MIDI interface.  This http://www.faqs.org/docs/Linux-HOWTO/MIDI-HOWTO.html seems to be the best Linux MIDI resource I can find at the moment.  Many older links for this subject are dead.
0

Featured Post

Efficient way to get backups off site to Azure

This user guide provides instructions on how to deploy and configure both a StoneFly Scale Out NAS Enterprise Cloud Drive virtual machine and Veeam Cloud Connect in the Microsoft Azure Cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Weekend adv creator 3 14
Debug VNC connection on CentOS7 server 22 70
how to rebuild XFS volume from LV 19 41
servlet filter example 37 46
A short article about a problem I had getting the GPS LocationListener working.
Fine Tune your automatic Updates for Ubuntu / Debian
This tutorial covers a practical example of lazy loading technique and early loading technique in a Singleton Design Pattern.
This tutorial explains how to use the VisualVM tool for the Java platform application. This video goes into detail on the Threads, Sampler, and Profiler tabs.

863 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

24 Experts available now in Live!

Get 1:1 Help Now