AW: [basicstamps] Hardware experiment
Archiver
Posts: 46,084
um....did I ask something wrong? this is the first time I get no answer at
all though its the second time I ask. Am I hurting the hidden hardware-codex
or sumthin' ? :-)
have a nice day, uli
Urspr
all though its the second time I ask. Am I hurting the hidden hardware-codex
or sumthin' ? :-)
have a nice day, uli
Urspr
Comments
supply to the stamp. Or, use a separate power source for the
stamp.
Doug
On 10 Oct 2001, at 19:22, ulibasic wrote:
> um....did I ask something wrong? this is the first time I get no
> answer at all though its the second time I ask. Am I hurting the
> hidden hardware-codex or sumthin' ? :-)
>
> have a nice day, uli
>
>
>
>
Urspr
I have results from my experiments with the Stamps' brownout posted at:
http://www.emesys.com/BS2power.htm#Brownout
The purpose of the chip is to prevent corruption of data that can
occur in brownout conditions. Probably you can get away with it
99.9% of the time, but then there is that last 0.1%....
BTW, the BS2e, sx and p do not have an external reset chip. That
function is built into the SX microprocessor.
In your efforts, did you ground the ATN input on the stamp (pin 3)?
Did you try a large filter capacitor on Vdd? Shielding? Careful
attention to ground loops?
-- regards
Tracy Allen
electronically monitored ecosystems
http://www.emesystems.com
mailto:tracy@e...
>um....did I ask something wrong? this is the first time I get no answer at
>all though its the second time I ask. Am I hurting the hidden hardware-codex
>or sumthin' ? :-)
>
>have a nice day, uli
>
>
>
>
Urspr
about things I didn't really understand...
Hi Uli:
The 8054HN is there to ensure reliability of the stamp process, if not to
reduce liability.
All it does is to provide a distinct point of minimum Vdd, or a threshold
that the Stamp should always function above. If you can live with the
consequences of it's elimination in your application you'll do just fine.
You could be getting some bit-scrambling that is inconsequential during the
noisy periods you are mentioning, and you may see these have negative
consequences as you log more hours on this particular stamp. On the other
hand, you may be getting away with this one. I seem to recall that the 8054
has a detect tolerance of +/- .2 V or so. As long as your hi In's stay above
1.5 and the stamp otherwise functions, (The regulator is going to be having
fits!) It will work until it crashes (OK, it can't really crash - it'll just
run afoul). With the Stamp being deterministic, you wouldn't know if
something failed unless/until it manifested in an output. In other words,
just because you can't see a problem, it doesn't mean there isn't one.
But does this mean that IF there are some scrambled bits I could fix them by
restarting the stamp?
It
was good design practice to include the 8054 for that reason alone. One neat
idea might be to use it's output on another input that you might use to goto
(oh, sorry, if then..)a diagnostic loop to ensure that the outside world
conditions are what you expect.
Sorry, didn't quite get this one. Does that mean I use the output of the
8054 on a normal stamp-input and whenever it goes high I use a routine to
check if everything is right? HOW would I check if WHAT is wrong?
Personally, I wouldn't remove the 8054 unless I had absolutely no way to get
the time needed to filter or de-couple the noise problem away properly.
Do you have any complete list of anti-noise-measures one can use? I tried
everything I could think of, including (oops, I am missing some english
words here,) those ferrit-things you wrap your wire around, zener-diodes,
caps over the power-supply, small caps against peaks, batteries as stamp
supply, grounded metal-case around the stamp....
What's the noise source anyway?
It is two valves driven by coils (220V~) and two aquarium air pumps (big
ones). The whole thing is a game called 'MINDBLOW' in which you hold up a
kind of hood over your head and ty to stay very calm (concentrate!). The
player who stays the calmest has his baloon inflated whereas the other one
loses air. (sounds VERY silly but is great fun... :-)
And one more question: how could I debug the possible invisible mistakes you
were thinking of? Just debug the variables and see if they behave right or
what do you suggest?
SSSSooooo many questions.....
Thanks a lot, chris
Uli
>
Original Message
> From: ulibasic [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=lZhn6SYlrydi_F8PivJWdzga2Jk0DVCzvjTwnZ5W5yeuCPhRWZdQbV-CC9Oao2mZHANz97hLh9gm6RTALVnuLb3QxJmwFpq8mabSzQ]ulibasic@r...[/url
> Sent: Wednesday, October 10, 2001 1:23 PM
> To: basicstamps@yahoogroups.com
> Subject: AW: [noparse][[/noparse]basicstamps] Hardware experiment
>
>
> um....did I ask something wrong? this is the first time I get
> no answer at
> all though its the second time I ask. Am I hurting the hidden
> hardware-codex
> or sumthin' ? :-)
>
> have a nice day, uli
>
>
>
>
Urspr