Re: Sensor wiring

From	stephenXXX@mpeforth.com (Stephen Pelc)
Newsgroups	comp.arch.embedded
Subject	Re: Sensor wiring
Organization	MPE
Message-ID	<5249d81b.642690157@news.demon.co.uk> (permalink)
References	<l2cbm8$qft$1@dont-email.me>
Date	2013-09-30 20:05 +0000

Show all headers | View raw

On Mon, 30 Sep 2013 13:16:55 -0400, Mel Wilson <mwilson@the-wire.com>
wrote:

>I want an I2C connection between a Raspberry Pi and an ATtiny85 over 35m of 
>buried wire.  Any guidelines for signal conditioning and protection?  
>Acknowledging that out-of-spec bits per second is a definite possiblity.

We have done this in a very noisy environment. You *need* to use
buffer chips like the NXP P82B96. See:
  http://ics.nxp.com/products/i2chubs/

I2C is an edge triggered protocol. Many I2C peripherals are very
sensitive to fast noise pulses. We often find bit-banged I2C to be
more reliable for masters than using the peripheral hardware.
I2C slave code for bit-banging is just nasty.

Stephen

-- 
Stephen Pelc, stephenXXX@mpeforth.com
MicroProcessor Engineering Ltd - More Real, Less Time
133 Hill Lane, Southampton SO15 5AF, England
tel: +44 (0)23 8063 1441, fax: +44 (0)23 8033 9691
web: http://www.mpeforth.com - free VFX Forth downloads

Thread

Sensor wiring Mel Wilson <mwilson@the-wire.com> - 2013-09-30 13:16 -0400
  Re: Sensor wiring Tim Wescott <tim@seemywebsite.really> - 2013-09-30 12:39 -0500
    Re: Sensor wiring Jim Stewart <jstewart@jkmicro.com> - 2013-09-30 11:05 -0700
    Re: Sensor wiring Mel Wilson <mwilson@the-wire.com> - 2013-09-30 14:25 -0400
      Re: Sensor wiring Rob Gaddi <rgaddi@technologyhighland.invalid> - 2013-09-30 11:40 -0700
        Re: Sensor wiring Tim Wescott <tim@seemywebsite.really> - 2013-09-30 14:17 -0500
      Re: Sensor wiring Johann Klammer <klammerj@NOSPAM.a1.net> - 2013-09-30 22:30 +0200
    Re: Sensor wiring Les Cargill <lcargill99@comcast.com> - 2013-09-30 21:55 -0500
  Re: Sensor wiring Don Y <this@isnotme.com> - 2013-09-30 11:58 -0700
  Re: Sensor wiring stephenXXX@mpeforth.com (Stephen Pelc) - 2013-09-30 20:05 +0000
    Re: Sensor wiring hamilton <hamilton@nothere.com> - 2013-09-30 15:22 -0600
      Re: Sensor wiring hamilton <hamilton@nothere.com> - 2013-09-30 15:23 -0600
    Re: Sensor wiring Dave Nadler <drn@nadler.com> - 2013-10-01 13:36 -0700
    Re: Sensor wiring Dave Nadler <drn@nadler.com> - 2013-10-01 13:39 -0700
  Re: Sensor wiring Vladimir Vassilevsky <nospam@nowhere.com> - 2013-09-30 16:58 -0500
    Re: Sensor wiring Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2013-10-01 08:44 +0200
  Re: Sensor wiring upsidedown@downunder.com - 2013-10-01 10:02 +0300
    Re: Sensor wiring Tom Gardner <spamjunk@blueyonder.co.uk> - 2013-10-01 09:11 +0100
  Re: Sensor wiring Paul Rubin <no.email@nospam.invalid> - 2013-10-01 00:36 -0700
  Re: Sensor wiring Paul E Bennett <Paul_E.Bennett@topmail.co.uk> - 2013-10-01 09:19 +0100

csiph-web