Date:         Wed, 20 Nov 2013 07:40:41 -0800
Reply-To:     Brett Ne <brettn777@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Brett Ne <brettn777@GMAIL.COM>
Subject:      Re: Arduino and Vanagons
In-Reply-To:  <CAHbJSdUAwGYWzctMTQRxm_Am9aqwCypq+vzk3JdancNMfbpmtA@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

VW may have spent millions developing the waterboxer, but it takes tens of
millions to do it properly.  It seems pretty clear to me that VW knew early
on that they were going to switch to an inline front engined front wheel
drive van(using the driver's & passenger's legs as part of the front
crumple zone is really not the best strategy) and never spent the resources
necessary to develop the waterboxer beyond just a basic level of
functionality.




On Tue, Nov 19, 2013 at 2:32 PM, Jim Akiba <syncrolist@bostig.com> wrote:

> You can measure the correct duty cycle for your setup. Get your PWM
> controller working manually (preferably with a dashpot input and
> output so you can read where you are) get the engine warmed up
> normally then interrupt it and see where "middle" is for the desired
> idle via your manual control when warm. You can then begin to work
> backwards and get the colder temps etc, unless you just watch/log the
> current outputs.
>
> This still wouldn't tell me the most important information that I need to
know: how is the idle air valve supposed to behave outside of the normal
idle conditions.  Is it supposed to be closed, partially open, or fully
open during engine startup, driving down the road, and fully open
throttle.  I haven't found a source that positively tells me how the idle
air valve should be behaving under these conditions, so I have to have some
measurements from a healthy controller in order to find out.  The other
measurements I'm asking for , the duty cycles at idle under various loads,
is not critical, but would give me a better idea of how aggressively the
code needs to change the pwm signal.  If it's not aggressive enough you get
lag, but if it's too aggressive you get overshoot and the potential for
oscillating behavior.




> The arduino stuff is cool, I built an OBDII to SD card autologger as
> well as a few more intense projects with the Parallax Propeller (much
> more powerful with 8 cores so the coding can be sloppier and no
> interrupts etc needed).
>

The Propeller chip is way cool.  It really makes life easier when you have
multiple critical timing events happening.  Eight independent
microcontrollers that are perfectly synchronized.  Even the Arduino is a
bit of overkill for this project.  But I want to add some additional
functionality to the ICU using some of the extra pins.  For example, an LED
that lights up when the throttle valve is closed or fully open so that you
can tell at a glance whether your throttle switch is working.




Brett in Portland
"Albert" '82 VanaFox I4 Riviera