Hi guys!
I just tried a slightly modified version of the program Neil used and
all of a sudden I got great results... The circuit I used was the same
as with my earlier tests. I really don't get why it didn't work
till
now!
It might have been because I didn't refresh it fast enough, but
wouldn't
you think once every millisecond should do?
Now I am getting
NondimVolt Voltage
0.5 2.36V
1.0 4.60V
Thanks to all of you for helping me!
Best regards
Sebastian Probst Eide
-----Original Message-----
From: Neil Jepsen [mailto:]
Sent: 21. oktober 2003 22:02
To:
Subject: Re: [BasicX] PutDAC - strange voltages :(
Sebastian
Whenever you are using more than one power supply, in
most cases ( nost not all) you must connect the grounds together. I
can't think of an instance except perhaps where you are using opto
isolators, where this would not be the case.
Your WIMA 0.1 is OK, but I'm surprised that the 10k didn't work,. this
points to your DVM being low impedance.
I just hooked up a BX24 as follows:
Pin 12 had a 10k in series with a 0.1 to ground. I used a Fluke DVM
Program was :
'******************************
public sub main()
dim daccounter as byte
do
call putdac(12,0.5,daccounter)
loop
end sub
'*******************************
The values I got were:-
nondimvolt: measured value:
0.25 1.3 volts
0.5 2.4v
0.75 3.5v
1.0 4.6v
Sebastian P. E. wrote:
Neil, I tried connecting the two grounds a week ago as I received your
post, and the results posted earlier this day where from that test, but
the voltages where still wrong so I didn't see any reason posting them
till Tom asked me if I actually had tried your advice.
1. I have never been connecting anything else to the pin except the
resistor (I have both tried a 1k (998ohm) and a 10k (9880ohm). I got
shitty results with the 10k resistor) and the capacitor (I have been
connecting my voltmeter though). I haven't even been using any of the
other pins at the same time.
2. The capacitors I have been using at my latest test have all been
in the range between 0.01 and 0.1uF. I have tried connecting them back
to front as well but they always deliver the same result. Is there a
way to determine whether a cap is electrolytic or not? I just grabbed
some parts from a box at my school and there is no documentation at all
and the inscriptions do not tell me much except the capacity. (On one:
0.1 | 63- A | S 2 | WIMA, on the other type: 0.01 | 100-A | WIMA | T21).
I haven't been able to find capacitors in any electronics store here in
Norway so far, believe me, I have tried several. and if the ones I have
got aren't electrolytic should work fine, shouldn't they? That is
if
they're not really old which I hope they're not.
3. I have got a brand new digital multimeter. It is called CM2701
and was made by Caltek instruments. I have been using it set to measure
DC volts.
4. I tried refreshing the pin every 1 milliseconds and every 0.1
milliseconds but the results stayed the same.
5. I tried pin 13, 14 and 15, all with the same results. Now I get
a voltage at up to 2.73V though! Hip hurray! Not quite 5V though.
Best regards
Sebastian Probst Eide
-----Original Message-----
From: Neil Jepsen [mailto:]
Sent: 21. oktober 2003 08:24
To:
Subject: Re: [BasicX] PutDAC - strange voltages :(
Sebastian...I told you about connecting the grounds together a week
ago!!
I would do the following:
1. Disconnect EVERYTHING from the pin you are testing, EXCEPT the
resistor and the capacitor.
2. The capacitor must be a non electrolytic and between 0.01 and 0.47
uF. The reason I say this is an electrolytic can be connected back to
front, or or might be leaky. If you use a mylar or similar, it can't be
connected wrongly.
3. You must use a digital voltmeter. Grand-dad's old analogue VOM
probably has a low input impedance. What meter are you using? Make
sure the meter is set to DC volts.
4. Refresh the pin as fast as you can
5. If this doesn't work, try one of the other output pins. You may have
damaged a pin.
5. Tell us what you get when you've done ALL of this.
neil
Sebastian P. E. wrote:
> Do not misunderstand me. My readings are NOT good,
just that the
> hardware problem isn't much of a problem any more! That single
problem
> is gone. The strange voltages from the chip are
still the same!
>
> Best regards
> Sebastian Probst Eide
> Web: <http://dagensstart.com/> Dagensstart.com
> Email: <mailto:>
> Phone: +47 9797 0000
>
> -----Original Message-----
> From: Sebastian P. E. [mailto:]
> Sent: 22. oktober 2003 07:20
> To:
> Subject: RE: [BasicX] PutDAC - strange voltages :(
>
> Hi Tom.
> After I connected ground on the two boards the problem disappeared.
> My readings are now good:
>
> GRN - GRN : 0V
> 5V strip on dev board and:
> -GND on dev board: 4.98V
> -GND on s.board: 4.98V (obviously)
> Positive strip on the s.board and
> -GND on dev board: 6.06V
> -GND on s.board: 6.06V (obviously)
> -5V strip on dev board: 1.08V
> Directly connected to PIN13 and GRN: 0.00-0.10V
> Directly connected to PIN13 and GRN through a low pass filter:
0.20-1.0V
> (depending on the different nondimVolt values (The
PutDAC is called
once
> every 5 milliseconds))
>
> Best regards
> Sebastian Probst Eide
> -----Original Message-----
> From: Tom Becker [mailto:]
> Sent: 21. oktober 2003 04:51
> To:
> Subject: RE: [BasicX] PutDAC - strange voltages :(
>
> Before you worry about code and low-pass filters, you need to solve
the
> hardware problems that you listed in a previous
message:
>
> > Positive pole on the s.board and gnd on the dev board while the
chip
> is in the dev board, I get: 0V (Should have been 6.06V as with the gnd
> on the s.board!)
> > +5 on the dev board and the gnd on the solderless board I get:
0.28V
> (should have been 4.98V!)
> > gnd on the dev board and the gnd on the s.board I get: -0.38V!
(should
> have been 0.0V!!)
>
> Until these are what they should and must be, you should defer more
> complex notions.
> Tom Becker
> --... ...--
> www.RighTime.com
> The RighTime Clock Company, Inc., Cape Coral, Florida USA
> +1239 540 5700
<http://rd.yahoo.com/M4081.4074964.5287182.1261774/D=egroupweb/S06
>
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>
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Your use
Sebastian P. E. wrote:
> Neil, I tried connecting the two grounds a week
ago as I received your
> post, and the results posted earlier this day where from that test,
but
> the voltages where still wrong so I didn't
see any reason posting them
> till Tom asked me if I actually had tried your advice.
>
> 1. I have never been connecting anything else to the pin except
the
> resistor (I have both tried a 1k (998ohm) and a
10k (9880ohm). I got
> shitty results with the 10k resistor) and the capacitor (I have been
> connecting my voltmeter though). I haven't even been using any of
the
> other pins at the same time.
> 2. The capacitors I have been using at my latest test have all
been
> in the range between 0.01 and 0.1uF. I have tried
connecting them
back
> to front as well but they always deliver the same
result. Is there a
> way to determine whether a cap is electrolytic or not? I just grabbed
> some parts from a box at my school and there is no documentation at
all
> and the inscriptions do not tell me much except
the capacity. (On one:
> 0.1 | 63- A | S 2 | WIMA, on the other type: 0.01 | 100-A | WIMA |
T21).
> I haven't been able to find capacitors in any
electronics store here
in
> Norway so far, believe me, I have tried several.
and if the ones I
have
> got aren't electrolytic should work fine,
shouldn't they? That is if
> they're not really old which I hope they're not.
> 3. I have got a brand new digital multimeter. It is called
CM2701
> and was made by Caltek instruments. I have been
using it set to
measure
> DC volts.
> 4. I tried refreshing the pin every 1 milliseconds and every 0.1
> milliseconds but the results stayed the same.
> 5. I tried pin 13, 14 and 15, all with the same results. Now I
get
> a voltage at up to 2.73V though! Hip hurray! Not
quite 5V though.
>
> Best regards
> Sebastian Probst Eide
> -----Original Message-----
> From: Neil Jepsen [mailto:]
> Sent: 21. oktober 2003 08:24
> To:
> Subject: Re: [BasicX] PutDAC - strange voltages :(
>
> Sebastian...I told you about connecting the grounds together a week
> ago!!
>
> I would do the following:
> 1. Disconnect EVERYTHING from the pin you are testing, EXCEPT the
> resistor and the capacitor.
> 2. The capacitor must be a non electrolytic and between 0.01 and 0.47
> uF. The reason I say this is an electrolytic can be connected back to
> front, or or might be leaky. If you use a mylar or similar, it
can't
be
> connected wrongly.
> 3. You must use a digital voltmeter. Grand-dad's old analogue VOM
> probably has a low input impedance. What meter are you using? Make
> sure the meter is set to DC volts.
> 4. Refresh the pin as fast as you can
> 5. If this doesn't work, try one of the other output pins. You may
have
>
> damaged a pin.
> 5. Tell us what you get when you've done ALL of this.
> neil
>
>
> Sebastian P. E. wrote:
>
> > Do not misunderstand me. My readings are NOT good, just that the
> > hardware problem isn't much of a problem any more! That single
> problem
> > is gone. The strange voltages from the chip are still the same!
> >
> > Best regards
> > Sebastian Probst Eide
> > Web: <http://dagensstart.com/> Dagensstart.com
> > Email: <mailto:>
> > Phone: +47 9797 0000
> >
> > -----Original Message-----
> > From: Sebastian P. E. [mailto:]
> > Sent: 22. oktober 2003 07:20
> > To:
> > Subject: RE: [BasicX] PutDAC - strange voltages :(
> >
> > Hi Tom.
> > After I connected ground on the two boards the problem disappeared.
> > My readings are now good:
> >
> > GRN - GRN : 0V
> > 5V strip on dev board and:
> > -GND on dev board: 4.98V
> > -GND on s.board: 4.98V (obviously)
> > Positive strip on the s.board and
> > -GND on dev board: 6.06V
> > -GND on s.board: 6.06V (obviously)
> > -5V strip on dev board: 1.08V
> > Directly connected to PIN13 and GRN: 0.00-0.10V
> > Directly connected to PIN13 and GRN through a low pass filter:
> 0.20-1.0V
> > (depending on the different nondimVolt values (The PutDAC is called
> once
> > every 5 milliseconds))
> >
> >
> >
> > Best regards
> > Sebastian Probst Eide
> >
> >
> > -----Original Message-----
> > From: Tom Becker [mailto:]
> > Sent: 21. oktober 2003 04:51
> > To:
> > Subject: RE: [BasicX] PutDAC - strange voltages :(
> >
> > Before you worry about code and low-pass filters, you need to solve
> the
> > hardware problems that you listed in a previous message:
> >
> > > Positive pole on the s.board and gnd on the dev board while
the
chip
> > is in the dev board, I get: 0V (Should have
been 6.06V as with the
gnd
> > on the s.board!)
> > > +5 on the dev board and the gnd on the solderless board I get:
0.28V
> > (should have been 4.98V!)
> > > gnd on the dev board and the gnd on the s.board I get: -0.38V!
> (should
> > have been 0.0V!!)
> >
> > Until these are what they should and must be, you should defer more
> > complex notions.
> >
> >
> > Tom Becker
> > --... ...--
> > www.RighTime.com
> > The RighTime Clock Company, Inc., Cape Coral, Florida USA
> > +1239 540 5700
> >
> >
> >
> >
> >
> >
> >
> >
>
<http://rd.yahoo.com/M4081.4074964.5287182.1261774/D=egroupweb/S06
> >
>
554205:HM/A32163/R=0/SIGn0nglqg/*http:/www.ediets.com/start.cfm?co
> > de0510&media=zone> click here
> >
> >
> >
>
<http://us.adserver.yahoo.com/l?M4081.4074964.5287182.1261774/D=egrou
> > pmail/S=:HM/A32163/rand75382935>
> >
> > ">http://docs.yahoo.com/info/terms/> Yahoo! Terms of Service.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
<http://rd.yahoo.com/M4081.4074964.5287182.1261774/D=egroupweb/S06
> >
>
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