OT - Do you ever look at an old schematic or old code and think...

What the hell was I smoking when I did this?

I'm finally trying to get a design into production
that I did two years ago.  The proto worked two
years ago.  It's still sitting on my desk.  The
preproduction unit I made yesterday didn't.
Looking at the schematic, it's pretty clear why
it didn't work.

What's not clear is what I was thinking when I
designed the proto...

On 06/24/2011 06:04 PM, Jim Stewart wrote:
> What the hell was I smoking when I did this?
>
> I'm finally trying to get a design into production
> that I did two years ago. The proto worked two
> years ago. It's still sitting on my desk. The
> preproduction unit I made yesterday didn't.
> Looking at the schematic, it's pretty clear why
> it didn't work.
>
> What's not clear is what I was thinking when I
> designed the proto...

So, did the prototype work by chance, or because you modded it and 
forgot to include your red lines?

I'm just assembling a board in stages, and writing software drivers as I 
go.  I've had a few of those "whatinhell" moments on this myself (mostly 
component footprints instead of rank circuitry errors -- but still).

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

Hi Jim,

On 6/24/2011 6:04 PM, Jim Stewart wrote:
> What the hell was I smoking when I did this?
>
> I'm finally trying to get a design into production
> that I did two years ago. The proto worked two
> years ago. It's still sitting on my desk. The
> preproduction unit I made yesterday didn't.
> Looking at the schematic, it's pretty clear why
> it didn't work.
>
> What's not clear is what I was thinking when I
> designed the proto...

Brain Flatulence.  :>

I laid out a six layer board, got the first samples
back and noticed a foil jumper *right* across another
foil.

"Now how the hell did I do *that*??"

<frown>

Are you sure you don't have another page of *notes*
someplace?  (or, perhaps it was *that* which you smoked!)

the difference between a pro and amateur is how well they know the
fundamentals, not the obscure stuff, even golf pros practice the
really basic fundamentals everyday, I find this is a good model to
follow for all disciplines and helps minimize most of those "I can't
believe I did that" moments,

On Jun 24, 9:04=A0pm, Jim Stewart <jstew...@jkmicro.com> wrote:
> What the hell was I smoking when I did this?
>
> I'm finally trying to get a design into production
> that I did two years ago. =A0The proto worked two
> years ago. =A0It's still sitting on my desk. =A0The
> preproduction unit I made yesterday didn't.
> Looking at the schematic, it's pretty clear why
> it didn't work.
>
> What's not clear is what I was thinking when I
> designed the proto...

My "what was I smoking" moments are usually more of the "What was I
smoking when I took on this job" type.  Actually I've never had a job
from "hell".  But some make more money than others.  There are times I
end up getting paid about the same as when I worked construction labor
during college summers.

Unless Google fixes their smoking habits, I'll never see any other
replies.  I need to find a newsreader.  I've had it with Google!

Rick

On Jun 25, 9:04=A0am, Jim Stewart <jstew...@jkmicro.com> wrote:
> What the hell was I smoking when I did this?
>
> I'm finally trying to get a design into production
> that I did two years ago. =A0The proto worked two
> years ago. =A0It's still sitting on my desk. =A0The
> preproduction unit I made yesterday didn't.
> Looking at the schematic, it's pretty clear why
> it didn't work.
>
> What's not clear is what I was thinking when I
> designed the proto...

Old code! huh.

I remember writing something a year before last year and I was in rush
to meet the damn deadline. The whole idea was to make it work whatever
was expected. The whole thing was to port the code form one platform
to another. But seriously, when I got back to the code after like 6
months It turn out to be _hell_. It was anything but a code.  I had my
reasons why this thing happened:

0) It was a new platform to me.
1) There was no documentation from company with respect to code layout
style or naming convention etc.
2) No clear requirements in drafted form.
3) I have to improve my self;-)

regards,
ali

Ali wrote:

[%X]

> Old code! huh.
> 
> I remember writing something a year before last year and I was in rush
> to meet the damn deadline. The whole idea was to make it work whatever
> was expected. The whole thing was to port the code form one platform
> to another. But seriously, when I got back to the code after like 6
> months It turn out to be _hell_. It was anything but a code.  I had my
> reasons why this thing happened:
> 
> 0) It was a new platform to me.
> 1) There was no documentation from company with respect to code layout
> style or naming convention etc.
> 2) No clear requirements in drafted form.
> 3) I have to improve my self;-)
> 
> regards,
> ali

....and for any others whose experience is similar to this, I can only 
suggest that recognising you need help to improve is the important first 
step. The next step should be to get a copy of Philip Koopman's book "Better 
Embedded Systems Software" and fix it to your development station, 
conveniently open at every single chapter simultaneously. Ok, I know that 
last ask is an impossible with a book, but you won't regret getting it and 
learning the lessons it contains. Good for the managers to read too.

<http://koopman.us/book.html>

-- 
********************************************************************
Paul E. Bennett...............<email://Paul_E.Bennett@topmail.co.uk>
Forth based HIDECS Consultancy
Mob: +44 (0)7811-639972
Tel: +44 (0)1235-510979
Going Forth Safely ..... EBA. www.electric-boat-association.org.uk..
********************************************************************

In article <iu3c7g$n1c$1@dont-email.me>, jstewart@jkmicro.com says...
> What the hell was I smoking when I did this?
> 
> I'm finally trying to get a design into production
> that I did two years ago.  The proto worked two
> years ago.  It's still sitting on my desk.  The
> preproduction unit I made yesterday didn't.
> Looking at the schematic, it's pretty clear why
> it didn't work.
> 
> What's not clear is what I was thinking when I
> designed the proto...

That is usually when I go get the ACTUAL file folder that has my 
original notes in it and usually a marked up PCB image with the piece of 
"Oops Wire" noted on it.  Just went through that recently.