Date:         Fri, 7 May 2010 15:25:22 -0500
Reply-To:     John Rodgers <inua@CHARTER.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         John Rodgers <inua@CHARTER.NET>
Subject:      Re: Analog to Digital Idle Stabilizer Control
Comments: To: John Bange <jbange@GMAIL.COM>
In-Reply-To:  <y2o6da579341005071255l7d75f1fcwb76545565692f7ec@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

John,

The minute I saw your name as sender the bell rung. Getting a few
cobwebs up in my belfry these days I'm afraid.

Sound like a thorny project - but I'll bet you are having fun toying
with it. Wish there was some way I could help. Unfortunately I'm not
much on electronics.

Thanks for the heads up. I know everyone is eager about this project.

Regards,

John R

John Rodgers
Clayartist and Moldmaker
88'GL VW Bus Driver
Chelsea, AL
Http://www.moldhaus.com


On 5/7/2010 2:55 PM, John Bange wrote:
>> My apologies - but I can never remember who is was/is working on a
>> digital replacement for the analog box just forward of the right hand
>> tail light.
>>
>> Anyone know what has become of that project?
>>
>>
>>
> That's me! I'm still plugging away at it as time permits. I have a test unit
> that can open the idle valve between 0 and 100%, but it doesn't have fine
> enough control. Idle jumps erratically from "nearly stalling" to "headed for
> red-line". I suspect the pulse width modulator built into the Atmel
> controller I'm using just doesn't work at a frequency the solenoid valve
> likes. Subsequently, I have to write a PWM routine myself from scratch--- a
> task I've been procrastinating on because it doesn't sound fun. The biggest
> problem is going to be to figure out what frequency WILL work. Trial and
> error is pretty tedious. I've been poking around for an oscilloscope so I
> can measure what the stock analog unit operates at, but nothing affordable
> has showed up yet.
>
> Still, my spare idle valve and the controller unit are always sitting front
> and center on my desk at home, and I do fiddle with it at least a couple
> times a week.
>
> --
> John Bange
>
>
>