[sdiy] Real cause of DIY death

[Bob Weigel]

Yeah if I presumed that I'd be wrong like...87% of the time or 
something.  Some people need a double edged razor..others can get by 
with the single. :-)  A good chunk of the time, there just is no likely 
answer at all that jumps out.  Eg.
 We have this rv jack project.  Earlier versions of the code seemed to 
work but had some lacking features that we determined critical.  I 
worked through to an implementation of those things that...works perfect 
on a little demo trailer have.  However when we take the same hardware 
out and attach it to a real 5th wheel, often the first thing after 
calibrating it, it shoots for a value way outside the limits when you 
give a command that should according to the software (which, in that 
respect hasn't really changed since the days when it was always working 
well .) should just calculate a position inside those limits 
proportioned by a reading from a slider from 0 to 5V from a slider.
      So...I bring the 'fouled' unit back to the little demo trailer 
and..it acts the same way; trying to scoot off to an absurd impossible 
position and break the jacks :-).  I reprogram the chip and...all is 
well.  Until you take it out on another 5th wheel.
       Now while it seems obvious this is being caused by a voltage 
transition somehow..rewriting something on the chip...! . since it 
happens in the high current environment but not in the low current 
one.....questions like 'why didn't this happen in the 30 units we sold 
but rather waited until it was about to be shown TO A BUNCH OF 
EXECUTIVES OF BIG COMPANIES???!!!!!!!   do tend to come to mind.  
And...I really can't think of an answer at this time to even pursue.  We 
added some lines to the code but...they don't really relate to this 
whole thing in any way we can see. 
        So many problems I run into are of this nature it seems and 
require a lot of work before you can even start 'shaving away' using a 
'razor' like this :-).  A lot of 'judicious guessing' as we called it in 
differential equations.  A lot of creative test insertions to try to 
make a problem manifest in a way that will lend some kind of clue as to 
what it's even related to.  -Bob

Scott Gravenhorst wrote:

>Occam's Razor does not presuppose that one is correct at all, it merely
>expresses that the simplest explanation is more likely to be true.  It is
>not an absolute.  That may be a fine distinction, but it is an important one.
>
>
>
>"James Coplin" <moog at qwest.net> wrote:
>  
>
>>Except, Occam's razor presumes that at least one of the possible
>>explanations is correct.  
>>
>>I personally struggle with this constantly as I am a Chinese historian but
>>not Chinese.  I can have two perfectly plausible and reasonable assertions
>>that explain a situation *as I see it* but often neither is wholly correct
>>because of my preconceived ideas of the field of study based on my western
>>background.
>>
>>James
>>
>>    
>>
>>>-----Original Message-----
>>>From: owner-synth-diy at dropmix.xs4all.nl [mailto:owner-synth-
>>>diy at dropmix.xs4all.nl] On Behalf Of Scott Gravenhorst
>>>Sent: Monday, July 18, 2005 1:50 PM
>>>To: synth-diy at dropmix.xs4all.nl
>>>Subject: Re: [sdiy] Real cause of DIY death
>>>
>>>jbv <jbv.silences at club-internet.fr> wrote:
>>>      
>>>
>>>>        
>>>>
>>>>>translation: people are pretty dumb as a whole... TV
>>>>>watchers are DUMBER.
>>>>>
>>>>>          
>>>>>
>>>>mmmh... sounds too simple to be true...
>>>>        
>>>>
>>>Occam's Razor.
>>>
>>>
>>>---------------------------------------------------------
>>>- Where merit is not rewarded, excellence fades.
>>>- Hydrogen is pointless without solar.
>>>- What good are laws that only lawyers understand?
>>>- The media's credibility should always be questioned.
>>>- The only good terrorist is a dead terrorist.
>>>- Governments do nothing well, save collect taxes.
>>>
>>>-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
>>>-- Linux Rex         | RedWebMail by RedStarWare
>>>-- FatMan: home1.gte.net/res0658s/fatman/
>>>-- NonFatMan: home1.gte.net/res0658s/electronics/
>>>-- Autodidactic Master of Arcane and Hidden Knowledge.
>>>
>>>      
>>>
>>
>>    
>>
>
>---------------------------------------------------------
>- Where merit is not rewarded, excellence fades.
>- Hydrogen is pointless without solar.
>- What good are laws that only lawyers understand?
>- The media's credibility should always be questioned.
>- The only good terrorist is a dead terrorist.
>- Governments do nothing well, save collect taxes.
>
>-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
>-- Linux Rex         | RedWebMail by RedStarWare
>-- FatMan: home1.gte.net/res0658s/fatman/
>-- NonFatMan: home1.gte.net/res0658s/electronics/
>-- Autodidactic Master of Arcane and Hidden Knowledge.
>
>
>
>  
>