Is my stamp blown? - suggestion
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Posts: 46,084
This has been a very informative debug session with lots of good basic step
by step testing.
I've seen similar question several times on this board by people questioning
whether their new stamp is good or not.
Rodent :
Why not take and formalize the debug process with expected values as you've
done in the lower part of this thread
Clean it up, add a couple of drawing and posit it in the download section
so next time it comes there is a place we can point the next new guy to so
he can check out his "Blown Stamp". He would at least have a series of
tests to do all the basic debug.
Better yet as new suggested tests, and failure examples show it could be
updated.
Some people lack basic debug skills, others lack the knowledge of expected
result or tolerances.
This could help a lot of people at a very frustrating time.
Also from your point you would only have to do it once more not every time
it comes up.
Original Message
From: Rodent [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=lmbSkdO3Ms0hm4-H_biJ6j-h5-BcqXKz5l_nHoqikGLtCFZ9FYrLQ-2oJvA-UFCSmoIAFAjc6O7b]daweasel@s...[/url
Sent: Thursday, October 03, 2002 10:17 AM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Re: Is my stamp blown?
There is probably nothing wrong with the cap -- chances are the meter can't
read the cap in circuit -- this is normal. From your readings, it sounds
like the AC adapter and regulator are fine.
I believe I misread the Stamp manual last night -- I looked at the schematic
this morning and found your voltage readings on the Stamp socket are
correct. The BoE regulator only powers the headers near the solderless
breadboard. The Stamp receives power between Vss (pin 4 & 23) and Vin (pin
24) and its onboard regulator powers the Stamp and the AppMod header.
If you are only seeing 3 volts between Stamp pins 4 & 21 and 23 & 21 it
sounds like the Stamp is bad -- this should read 5 volts if the regulator on
the Stamp is working properly.
I would remove the Stamp and make sure nothing is plugged into the AppMod
header and that there are no shorts on the back side of the board around the
Stamp socket or AppMod header. You could also use the meter to check for
shorts between the Vss header and each Stamp pin -- if one pin is shorted
and the Stamp is configured for output on that pin you would have a problem
as well.
If you don't find anything I would see about getting the Stamp replaced.
Original Message
> > The voltage readings you claim you got off the regulator bother
> me, so I'm
> > wondering if you were checking it on the right pins. If Vdd is
> really that
> > low the Stamp is never powering up.
>
> You got that right, I was assuming the leftmost pin was common, not
> center (So its been 14 years since I did anything with
> electronics [noparse]:)[/noparse]. The voltages off the regulator are 14.8 and 5.0.
> Guess this is fine.
>
> > Set the meter to continuity or ohms and check for a short between
> pins 4,
> > 24, 23 and 21. You should only have continuity between pins 4 and
> 23.
>
> With the stamp removed and checking just the stamp socket with no
> power to the board I get:
>
> 4->24 is open
> 21->23 is 0.1 ohms
> 4-23 is 3 ohms
>
> Voltages between these pins (stamp removed)
> 4->24 14.4
> 4->23 0
> 4->21 0.3
> 23->21 0.3
> 23->24 14.4
>
> Voltages between these pins (stamp installed)
> 4->24 11.2
> 4->23 -0.1
> 4->21 3.0
> 23->21 3.0
> 23->24 11.8
>
> > Verify the AC adapter label says the output is somewhere around 9
> volts DC.
> > Make absolutely sure it says DC.
>
> Yep, 9v DC - this is the PS that came with the BOE kit - I did look
> at the rating as soon as I saw 14.8vdc when I checked it with the
> meter.
>
> > If this works, insert a short piece of bare wire into the Vss
> socket at the
> > top of the solderless breadboard and connect the black lead of
> your meter to
> > it. Insert a short piece of bare wire into the Vdd socket at the
> top of the
> > solderless breadboard and connect the red lead of your meter to
> it. The
> > meter should read about 4.9 to 5.1 volts DC.
>
> Checked, its 5.0 volts exactly.
>
> I also just checked the two capacitors (marked 1000uF each). One is
> showing 2500 uF on it (closest to edge of the BOE) while the other
> is 1030ish. I'm guessing the 2500 uF one is a bit messed up?
>
> p.s. Originally used my Ammeter for testing but brought home my
> fluke #12 last night since it has capacitance too. My work deals
> with simple electrical (volts,amp draw and continuity are about it)
> so I've taken to using the combined ammeter/voltmeter for
> convenience. Guess I'll "store" the #12 at home from now on.
>
> As for the software settings:
>
> I put in the BS2 and baud directives (BOE has the BS2, not the e or
> x etc). I had already tried deleting com2 (PC only has one com port
> attached).
>
> I also took the BOE to work yesterday and tried it on a win 98
> machine with the same result.
>
> Guess I'll stop by Active Components on my way to work and pick up
> another 1000uF cap! Should be warranty but I'd rather buy some parts
> and fix it today than mail everything in and wait 12 weeks [noparse]:D[/noparse]
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[noparse][[/noparse]Non-text portions of this message have been removed]
by step testing.
I've seen similar question several times on this board by people questioning
whether their new stamp is good or not.
Rodent :
Why not take and formalize the debug process with expected values as you've
done in the lower part of this thread
Clean it up, add a couple of drawing and posit it in the download section
so next time it comes there is a place we can point the next new guy to so
he can check out his "Blown Stamp". He would at least have a series of
tests to do all the basic debug.
Better yet as new suggested tests, and failure examples show it could be
updated.
Some people lack basic debug skills, others lack the knowledge of expected
result or tolerances.
This could help a lot of people at a very frustrating time.
Also from your point you would only have to do it once more not every time
it comes up.
Original Message
From: Rodent [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=lmbSkdO3Ms0hm4-H_biJ6j-h5-BcqXKz5l_nHoqikGLtCFZ9FYrLQ-2oJvA-UFCSmoIAFAjc6O7b]daweasel@s...[/url
Sent: Thursday, October 03, 2002 10:17 AM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Re: Is my stamp blown?
There is probably nothing wrong with the cap -- chances are the meter can't
read the cap in circuit -- this is normal. From your readings, it sounds
like the AC adapter and regulator are fine.
I believe I misread the Stamp manual last night -- I looked at the schematic
this morning and found your voltage readings on the Stamp socket are
correct. The BoE regulator only powers the headers near the solderless
breadboard. The Stamp receives power between Vss (pin 4 & 23) and Vin (pin
24) and its onboard regulator powers the Stamp and the AppMod header.
If you are only seeing 3 volts between Stamp pins 4 & 21 and 23 & 21 it
sounds like the Stamp is bad -- this should read 5 volts if the regulator on
the Stamp is working properly.
I would remove the Stamp and make sure nothing is plugged into the AppMod
header and that there are no shorts on the back side of the board around the
Stamp socket or AppMod header. You could also use the meter to check for
shorts between the Vss header and each Stamp pin -- if one pin is shorted
and the Stamp is configured for output on that pin you would have a problem
as well.
If you don't find anything I would see about getting the Stamp replaced.
Original Message
> > The voltage readings you claim you got off the regulator bother
> me, so I'm
> > wondering if you were checking it on the right pins. If Vdd is
> really that
> > low the Stamp is never powering up.
>
> You got that right, I was assuming the leftmost pin was common, not
> center (So its been 14 years since I did anything with
> electronics [noparse]:)[/noparse]. The voltages off the regulator are 14.8 and 5.0.
> Guess this is fine.
>
> > Set the meter to continuity or ohms and check for a short between
> pins 4,
> > 24, 23 and 21. You should only have continuity between pins 4 and
> 23.
>
> With the stamp removed and checking just the stamp socket with no
> power to the board I get:
>
> 4->24 is open
> 21->23 is 0.1 ohms
> 4-23 is 3 ohms
>
> Voltages between these pins (stamp removed)
> 4->24 14.4
> 4->23 0
> 4->21 0.3
> 23->21 0.3
> 23->24 14.4
>
> Voltages between these pins (stamp installed)
> 4->24 11.2
> 4->23 -0.1
> 4->21 3.0
> 23->21 3.0
> 23->24 11.8
>
> > Verify the AC adapter label says the output is somewhere around 9
> volts DC.
> > Make absolutely sure it says DC.
>
> Yep, 9v DC - this is the PS that came with the BOE kit - I did look
> at the rating as soon as I saw 14.8vdc when I checked it with the
> meter.
>
> > If this works, insert a short piece of bare wire into the Vss
> socket at the
> > top of the solderless breadboard and connect the black lead of
> your meter to
> > it. Insert a short piece of bare wire into the Vdd socket at the
> top of the
> > solderless breadboard and connect the red lead of your meter to
> it. The
> > meter should read about 4.9 to 5.1 volts DC.
>
> Checked, its 5.0 volts exactly.
>
> I also just checked the two capacitors (marked 1000uF each). One is
> showing 2500 uF on it (closest to edge of the BOE) while the other
> is 1030ish. I'm guessing the 2500 uF one is a bit messed up?
>
> p.s. Originally used my Ammeter for testing but brought home my
> fluke #12 last night since it has capacitance too. My work deals
> with simple electrical (volts,amp draw and continuity are about it)
> so I've taken to using the combined ammeter/voltmeter for
> convenience. Guess I'll "store" the #12 at home from now on.
>
> As for the software settings:
>
> I put in the BS2 and baud directives (BOE has the BS2, not the e or
> x etc). I had already tried deleting com2 (PC only has one com port
> attached).
>
> I also took the BOE to work yesterday and tried it on a win 98
> machine with the same result.
>
> Guess I'll stop by Active Components on my way to work and pick up
> another 1000uF cap! Should be warranty but I'd rather buy some parts
> and fix it today than mail everything in and wait 12 weeks [noparse]:D[/noparse]
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from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
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[noparse][[/noparse]Non-text portions of this message have been removed]
Comments
him in the wrong direction by assuming it was a software or cable issue.
Original Message
> This has been a very informative debug session with lots of good basic
step
> by step testing.
> I've seen similar question several times on this board by people
questioning
> whether their new stamp is good or not.
> Why not take and formalize the debug process with expected values as
you've
> done in the lower part of this thread
> Clean it up, add a couple of drawing and posit it in the download section
> so next time it comes there is a place we can point the next new guy to so
> he can check out his "Blown Stamp". He would at least have a series of
> tests to do all the basic debug.
> Too much work to do for free. I only wrote it because people were
steering
> him in the wrong direction by assuming it was a software or cable
issue.
>
And you were dead on [noparse]:D[/noparse] Bought a new stamp this morning and plugged
it into the old board. Its now happily ditting and dahing
temperature readings. Board appears just fine.
I took a look at the schematic for the BS2 and found the onboard
regulator. I was assuming the board regulator was supplying the
+5vdc until you pointed out that it was onboard. I checked and sure
enough, the onboard is putting out +3vdc when I power it seperate
from the BOE.
While I was there, I also picked up Al Williams book (Missed it the
first time around). Just the faq on the CD has answered just about
every question I've come up with so far! Well worth the bux!
died. The processor was bad and Parallax replaced it for me under warranty.
Other than a dead pin here or there from careless breadboarding I haven't
had a problem with the 10 or so Stamps I have.
I would contact Parallax and see if they will warranty the bad Stamp for
you.
Original Message
> > Too much work to do for free. I only wrote it because people were
> steering
> > him in the wrong direction by assuming it was a software or cable
> issue.
> >
>
> And you were dead on [noparse]:D[/noparse] Bought a new stamp this morning and plugged
> it into the old board. Its now happily ditting and dahing
> temperature readings. Board appears just fine.
>
> I took a look at the schematic for the BS2 and found the onboard
> regulator. I was assuming the board regulator was supplying the
> +5vdc until you pointed out that it was onboard. I checked and sure
> enough, the onboard is putting out +3vdc when I power it seperate
> from the BOE.
>
> While I was there, I also picked up Al Williams book (Missed it the
> first time around). Just the faq on the CD has answered just about
> every question I've come up with so far! Well worth the bux!
>
>
>
> 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/
>
>