Basic analog and digital conversion projects
Archiver
Posts: 46,084
Have you tried another POT? The current one may be noisey?
--- In basicstamps@yahoogroups.com, Hudson T Clark
<dark_archon1@j...> wrote:
> I have this stuff I'm doing for school and this one project that
has you
> make a DVM with the basic stamp and lm0831 A/D chip... Ok I
got
> everything to work and I finished all the challenges... The
problem is in
> the decimal display of the debug window sometimes there is a
glitch and
> for example when I'm rolling over to exactly 1v it will glitch and
show
> 2v... Its a little buggy when I move the POT around a lot like this
it
> will do it for other values to... I was just wondering is this just
an
> instability of the basic stamp or am I screwing something up?
Has anyone
> else experienced this? Can someone give me any input to
what the problem
> could be?
--- In basicstamps@yahoogroups.com, Hudson T Clark
<dark_archon1@j...> wrote:
> I have this stuff I'm doing for school and this one project that
has you
> make a DVM with the basic stamp and lm0831 A/D chip... Ok I
got
> everything to work and I finished all the challenges... The
problem is in
> the decimal display of the debug window sometimes there is a
glitch and
> for example when I'm rolling over to exactly 1v it will glitch and
show
> 2v... Its a little buggy when I move the POT around a lot like this
it
> will do it for other values to... I was just wondering is this just
an
> instability of the basic stamp or am I screwing something up?
Has anyone
> else experienced this? Can someone give me any input to
what the problem
> could be?
Comments
noisy, and it'll have jumps or irregularities in the readings.
Your program is OK. But you could possibly modify it to compensate for the
flaky pot by taking three readings from the ADC and average them, or take
three readings, throw away the most out of range one, and average the other
two. Depending on your program you could take 4-5 readings and throw away
the worst one and average the others as well.
Another approach would be besides taking multiple readings is to track
whether the pot is turning left or right, from previous readings, and to
ignore (at least momentarily) the first few irregular readings that have it
look like it's moving in the wrong direction.
Original Message
From: Hudson T Clark [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Fp9wTI3lDgfln49mknHyF--sNTuZBmGK51x3fkUqmawcgSRoxlnlW4PArG5B7Y-ffEtKhebgdxD-kVygk9gh]dark_archon1@j...[/url
Sent: Monday, June 16, 2003 4:01 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Basic analog and digital conversion projects
I have this stuff I'm doing for school and this one project that has you
make a DVM with the basic stamp and lm0831 A/D chip... Ok I got
everything to work and I finished all the challenges... The problem is in
the decimal display of the debug window sometimes there is a glitch and
for example when I'm rolling over to exactly 1v it will glitch and show
2v... Its a little buggy when I move the POT around a lot like this it
will do it for other values to... I was just wondering is this just an
instability of the basic stamp or am I screwing something up? Has anyone
else experienced this? Can someone give me any input to what the problem
could be?
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
circuit? wouldn't it average the readings and eleminate much of the
noise ?
also, is the pot a multi-turn? I found that using old parts
sometimes have problems.
Dave
--- In basicstamps@yahoogroups.com, "Earl Bollinger"
<earlwbollinger@a...> wrote:
> It is probably the potentiometer your using. The wiper can be what
they call
> noisy, and it'll have jumps or irregularities in the readings.
>
> Your program is OK. But you could possibly modify it to compensate
for the
> flaky pot by taking three readings from the ADC and average them,
or take
> three readings, throw away the most out of range one, and average
the other
> two. Depending on your program you could take 4-5 readings and
throw away
> the worst one and average the others as well.
> Another approach would be besides taking multiple readings is to
track
> whether the pot is turning left or right, from previous readings,
and to
> ignore (at least momentarily) the first few irregular readings that
have it
> look like it's moving in the wrong direction.
>
>
>
>
Original Message
> From: Hudson T Clark [noparse][[/noparse]mailto:dark_archon1@j...]
> Sent: Monday, June 16, 2003 4:01 AM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Basic analog and digital conversion projects
>
>
> I have this stuff I'm doing for school and this one project that
has you
> make a DVM with the basic stamp and lm0831 A/D chip... Ok I got
> everything to work and I finished all the challenges... The problem
is in
> the decimal display of the debug window sometimes there is a glitch
and
> for example when I'm rolling over to exactly 1v it will glitch and
show
> 2v... Its a little buggy when I move the POT around a lot like this
it
> will do it for other values to... I was just wondering is this just
an
> instability of the basic stamp or am I screwing something up? Has
anyone
> else experienced this? Can someone give me any input to what the
problem
> could be?
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
Subject and
> Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
In the case of a pot, it isn't distortion, per se. Instead its the result of
grinding. Most pots are either wire-wound (a bobbin with resistance wire
form wound onto it) or carbon (a cylinder or disc). In either case, a
suitable "wiper" (the center tap in a schematic with a pot in it) is used to
slide around or over the surface, under a slight spring tension. In the
event that the pot surface, or the wiper surface, or both, oxidizes (happens
constantly, its why solid state volume controls, DAC based, or using active
op-amps, are so popular in audio gear), the noise factor rises when you move
a pot, and as the spring tension on the wiper ages, the wiper starts making
microscopic bounces (more noise), and your readings all go bad (or your ears
hurt worse).
Mic
See what weird things you can learn in the US Navy?
Original Message
From: Hudson T Clark <dark_archon1@j...>
To: <basicstamps@yahoogroups.com>
Cc: <basicstamps@yahoogroups.com>
Sent: Monday, June 16, 2003 5:14 PM
Subject: Re: [noparse][[/noparse]basicstamps] Basic analog and digital conversion projects
> Yeah thats what everyone is saying, it didn't pop into my head I didn't
> think a POT could be noisy... but it makes sense... I know what "noise"
> is its unwanted distortion that messes up your signal.
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
1982. Electronics never dies, though!) So I'm not sure what book you refer
to, but would like to know. I always found the level of detail in Navy
training to be better than any of the other services, with apologies to
those in the other services. But I did attend courses taught by the USAF,
USN, and the US Army, and I still thought the Navy was best for quality and
depth of detail.
Mic
Original Message
From: Hudson T Clark <dark_archon1@j...>
To: <basicstamps@yahoogroups.com>
Cc: <basicstamps@yahoogroups.com>
Sent: Monday, June 16, 2003 6:43 PM
Subject: Re: [noparse][[/noparse]basicstamps] Basic analog and digital conversion projects
> Oh ok yeah maybe I didn't use the correct words but I understand what is
> going on. Btw if you are in the navy I like that navy electronics book
> they have... I forget what its called but that thing is a nice reading
> for anyone interested in electronics.
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
get you into basic electronics, but it is precisely that attention to, and
level of detail that made me like the Navy electronics courses I took so
much. One of the things impressed on us even then was that if you don't have
a component, be it a resistor, or capacitor, or whatever, and the ship is in
dire need of that precise piece of equipment to be able to work, a pretty
little commercial unit is not near as necessary tomorrow as a big ugly kluge
is today, so we'd better be able to make it from literally ANY piece of junk
laying around. And understanding molecular physics, and a modicum of math to
use with that knowledge, let us design caps from really weird stuff, like
cling-film, aluminum foil, and paper clips, and actually be able to
calculate its value before building it, leaving only the need to squeeze the
roll gently in order to fine tune it. We also made a makeshift television
reciever out of two broadband RF recievers and an oscilloscope. Great fun,
that theory, but we did that while I was overseas, and just cause we wanted
to. But it did prove my point about the Navy's educational materials being
the best available, if you just apply the knowledge.
Mic
Original Message
From: Hudson T Clark <dark_archon1@j...>
To: <basicstamps@yahoogroups.com>
Cc: <basicstamps@yahoogroups.com>
Sent: Tuesday, June 17, 2003 1:31 AM
Subject: Re: [noparse][[/noparse]basicstamps] Basic analog and digital conversion projects
> I can't really remember and I looked threw my IE history I couldn't find
> it, but I think its like the basic electronics one they make people read
> maybe it goes over like all the basic stuff... like resistor networks,
> they even had like some nuclear stuff I think???
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
Knowing that has helped me in too many ways, since I never really got out of
the sciences. I am a computer geek now, and a budding robogeek, but I will
not ever quit designing bigger and better ways to make things spark, flash,
boom, bang, and fling potatoes and such in the air. And knowing something
about all sorts of physics REALLY helps when you are trying to decide just
how big a bunker you need to be in before you touch that last honking
monster off. It also helps when I'm trying to iron the bugs out of a
gas-turbine conversion to a Chevy pickup truck, selecting fuels, figuring
out jetting for the turbine, finding suitable braking systems, etc.
Life is a classroom, and only dropouts quit learning!!
Mic
Original Message
From: Hudson T Clark <dark_archon1@j...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, June 18, 2003 12:50 AM
Subject: Re: [noparse][[/noparse]basicstamps] Basic analog and digital conversion projects
> Yeah but molecular theory is needed I think anyway to understand much of
> electronics. You need to understand what exactly electricity is to
> understand how we are using it... I mean you can say like analogies to
> explain how components behave but the little diagrams in most books of
> electrons, protons, ions, etc moving around really help when
> understanding how exactly components work.
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
make a DVM with the basic stamp and lm0831 A/D chip... Ok I got
everything to work and I finished all the challenges... The problem is in
the decimal display of the debug window sometimes there is a glitch and
for example when I'm rolling over to exactly 1v it will glitch and show
2v... Its a little buggy when I move the POT around a lot like this it
will do it for other values to... I was just wondering is this just an
instability of the basic stamp or am I screwing something up? Has anyone
else experienced this? Can someone give me any input to what the problem
could be?
think a POT could be noisy... but it makes sense... I know what "noise"
is its unwanted distortion that messes up your signal.
going on. Btw if you are in the navy I like that navy electronics book
they have... I forget what its called but that thing is a nice reading
for anyone interested in electronics.
it, but I think its like the basic electronics one they make people read
maybe it goes over like all the basic stuff... like resistor networks,
they even had like some nuclear stuff I think???
electronics. You need to understand what exactly electricity is to
understand how we are using it... I mean you can say like analogies to
explain how components behave but the little diagrams in most books of
electrons, protons, ions, etc moving around really help when
understanding how exactly components work.
lot of intellectual respect for people that go to school unless they give
me a reason to. I go to college myself, and I have dropped out of high
school. I started going to this community college near my house when I
was 17 for electronics as my major. It's funny... I have a pretty dark
past until I found out about these little buggers we call "computers" now
I'm like most uber geek!!! It's sad sometimes I get so frustrated that
some of my other peers are so not good at it. I hate how people believe
that someone is smart just because a piece of paper says so. Right now
I'm really into electronics... I also do computer programming... my web
page is http://dark.zemos.net soon I will be releasing one project I'm
working on called CGI::Marijuana which is a massive content loader module
for perl (think of every CGI script you have ever seen all in one perl
module
have never taken a programming class in my life and I have a good feeling
I can probably code better then the graduates from my school. Not saying
I'm smarter then everyone just most of the people I have encountered at
school. I know for a fact that many people exist that know an insanely
large amount more so then me.
But it is so much to ask for some common sense? You know I bet you
wouldn't believe it but I have experienced students arguing on steps
behind the physics building about what an "if" statement does. i.e.:
if(1) {
do this heh
}