LinuxQuestions.org
Help answer threads with 0 replies.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware
User Name
Password
Linux - Hardware This forum is for Hardware issues.
Having trouble installing a piece of hardware? Want to know if that peripheral is compatible with Linux?

Notices


Reply
  Search this Thread
Old 10-01-2005, 09:45 AM   #1
Mike Davies
Member
 
Registered: Jul 2004
Distribution: Custom Linux 4/Busybox. Fedora 22, Raspberry Pi
Posts: 98

Rep: Reputation: 15
Parallel port/i2c interfacing question


I have an i2c interface built around the old Philips design of a 74LS05 and 10k pull-up resistors on my PCs parallel port. (If you donít know this design see http://www.raphnet.net/electronique/...ts/lpt-i2c.txt)

It works OK(ish) with the standard Linux bit-bashing driver, but every now and again, say once every 100 I/O operations it fails. Until now, Iíve only had one i2c device on the bus and Iíve programmed around the problems by doing a re-read or re-write if my original I/O request failed.

I now want to add another device, and when I do, nothing works at all. The waveforms get very distorted. Either device on itís own is OK, but together, no joy.

I am wondering if there is an inherent fault in this design of interface and if the pull-up values need changing if I add more devices. My i2c bus is less than 30cm long.

Has anyone here experience of using the Linux drivers to interface to external hardware ? If so, do you use the Philips design/driver, and if not, what ?

Is there an i2c guru reading this that can give me some advice about bus loading ?
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
Problem with Linux/SX28AC i2c interfacing Mike Davies Linux - Hardware 0 11-24-2005 02:32 PM
slow parallel port / printer question tommyj27 Slackware 4 09-22-2003 11:18 PM
interfacing using perl(parallel port) teao Programming 1 07-29-2003 04:47 AM
new dumb question: use of parallel port ZIP? JapKraut Linux - Newbie 9 09-18-2001 08:52 PM
Interfacing Video camera with USB port Tanyakolee Linux - General 1 06-12-2001 03:17 AM

LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware

All times are GMT -5. The time now is 10:34 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration