Inputs left floating at the very start

On May 3, 3:39 pm, Robert Adsett <s...@aeolusdevelopment.com> wrote:
> In article <d2913c07-414d-458f-b3bd-5a0c7361f541
> @p39g2000prm.googlegroups.com>, linnix says...
>
> > On May 3, 2:50 pm, Hans-Bernhard Br=F6ker <HBBroe...@t-online.de> wrote:=

> > > linnix wrote:
> > > > On May 3, 11:26 am, Hans-Bernhard Br=F6ker <HBBroe...@t-online.de>
> > > > wrote:
> > > >> You might be amazed what people will notice...  A 10ms flash of an =
LED
> > > >> at full throttle is quite noticeable.
> > > > Yes, but does it really matter.  We expect something strange at
> > > > startup anyway.
>
> > > Well, for the devices we build at my place of work, random flashing at=

> > > power-up like that would eventually put us out of business.  Customers=

> > > will not accept such glitches, period.
>
> > I can't image what application would be so mission critical at power
> > up,
>
> As an examplehttp://www.navitastechnologies.com/hydraulic.html
>

But that's not driving LEDs.  Driving pumps and motors are certainly
different  from flashing LEDs.

linnix wrote:
> On May 3, 2:50 pm, Hans-Bernhard Br&#4294967295;ker <HBBroe...@t-online.de> wrote:

>> Well, for the devices we build at my place of work, random flashing at
>> power-up like that would eventually put us out of business.  Customers
>> will not accept such glitches, period.

> I can't image what application would be so mission critical at power
> up, but I'll take your words for it.

There's no need to make mission-critical mistakes to disgruntle our 
customers' customers, and eventually drive our customers to take their 
business elsewhere.  Nagging glitches are perfectly capable of having 
that effect in a pretty expensive extra for cars.

In article <33bd93fc-b031-4a4c-8366-8ad006ada7e3
@f24g2000prh.googlegroups.com>, linnix says...
> On May 3, 3:39 pm, Robert Adsett <s...@aeolusdevelopment.com> wrote:
> > In article <d2913c07-414d-458f-b3bd-5a0c7361f541
> > @p39g2000prm.googlegroups.com>, linnix says...
> >
> > > On May 3, 2:50 pm, Hans-Bernhard Br&#4294967295;ker <HBBroe...@t-online.de> wrote:
> > > > linnix wrote:
> > > > > On May 3, 11:26 am, Hans-Bernhard Br&#4294967295;ker <HBBroe...@t-online.de>
> > > > > wrote:
> > > > >> You might be amazed what people will notice...  A 10ms flash of an LED
> > > > >> at full throttle is quite noticeable.
> > > > > Yes, but does it really matter.  We expect something strange at
> > > > > startup anyway.
> >
> > > > Well, for the devices we build at my place of work, random flashing at
> > > > power-up like that would eventually put us out of business.  Customers
> > > > will not accept such glitches, period.
> >
> > > I can't image what application would be so mission critical at power
> > > up,
> >
> > As an example http://www.navitastechnologies.com/hydraulic.html
> >
> 
> But that's not driving LEDs.  Driving pumps and motors are certainly
> different  from flashing LEDs.

Well if you are going to restrict your outputs to flashing LEDs .... :)

I can certainly imagine it being a quality issue though, even with LEDs.  

Robert
** Posted from http://www.teranews.com **

Tom�s � h�ilidhe wrote:
> On May 3, 3:19 pm, rickman <gnu...@gmail.com> wrote:
> 
>> Why can't you just measure it?  As soon as the CPU start executing
>> code, toggle a pin from low to high to low.  No matter what state the
>> pin was before initialization, you will get an edge from this
>> sequence.
> 
> My stopwatch only measures accurate to a tenth of a second, plus my
> reflexes aren't quick enough to stop it accurately.
> 
> Seriously though what kind of device would I use to measure this? I'd
> need it to start measuring from when power was applied and get it to
> mark when the pin goes high.

My primary debugging tool is a digital oscilloscope.  For you application 
the trigger is CPU power and the other channel is your toggle pin.

-- 
Thad