Output pin glitches
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Posts: 46,084
I have noticed that the output pin of the stamp BSII
glitches to low every 2.1 Seconds.
The setup is simple: the stamp is powered from a
stable 9 Volt power supply. code is simply :
high 7
when u monitor pin 7 using a non - triggered rolling
mode of the scope ...a high to low glitch pulse every
2.1 seconds occurs.
I have heard of someone else having the same problem.
Kindly advise..i have checked and the stamp does not
reset so the problem is surely somethings else.
what am i missing here?
thankyou
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glitches to low every 2.1 Seconds.
The setup is simple: the stamp is powered from a
stable 9 Volt power supply. code is simply :
high 7
when u monitor pin 7 using a non - triggered rolling
mode of the scope ...a high to low glitch pulse every
2.1 seconds occurs.
I have heard of someone else having the same problem.
Kindly advise..i have checked and the stamp does not
reset so the problem is surely somethings else.
what am i missing here?
thankyou
__________________________________
Do you Yahoo!?
SBC Yahoo! DSL - Now only $29.95 per month!
http://sbc.yahoo.com
Comments
High 7
End
Where the End is implied. TO stop this behavior try this:
High 7
Endpgm:
goto endpgm
That should solve your problem. I think there is an article about this
at http://www.wd5gnr.com/stampfaq.htm
Al Williams
AWC
* Floating point math for the Stamp, PIC, SX, or any microcontroller
http://www.al-williams.com/awce/pak1.htm
>
Original Message
> From: harshit suri [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=460fX3TeUAJQmsqEU9SEsNgWkC9nEISE79A7_2_YmooTGDCT9upKTul99J2U7n4Py7Uo2klAX6C8FuZr]suri_list@y...[/url
> Sent: Monday, June 23, 2003 6:37 PM
> To: stamp
> Subject: [noparse][[/noparse]basicstamps] Output pin glitches
>
>
> I have noticed that the output pin of the stamp BSII
> glitches to low every 2.1 Seconds.
> The setup is simple: the stamp is powered from a
> stable 9 Volt power supply. code is simply :
>
> high 7
>
> when u monitor pin 7 using a non - triggered rolling
> mode of the scope ...a high to low glitch pulse every
> 2.1 seconds occurs.
> I have heard of someone else having the same problem.
> Kindly advise..i have checked and the stamp does not
> reset so the problem is surely somethings else.
> what am i missing here?
> thankyou
>
>
>
>
> __________________________________
> Do you Yahoo!?
> SBC Yahoo! DSL - Now only $29.95 per month! http://sbc.yahoo.com
>
> 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/
>
>
>
the first place. seems like a watchdog timer type
behaviour ..I tried seeing the FAQ . couldnt find the
article.
thankyou
--- Al Williams <alw@a...> wrote:
> Your program is really:
>
> High 7
> End
>
> Where the End is implied. TO stop this behavior try
> this:
>
> High 7
> Endpgm:
> goto endpgm
>
> That should solve your problem. I think there is an
> article about this
> at http://www.wd5gnr.com/stampfaq.htm
>
>
> Al Williams
> AWC
> * Floating point math for the Stamp, PIC, SX, or any
> microcontroller
> http://www.al-williams.com/awce/pak1.htm
>
>
>
> >
Original Message
> > From: harshit suri [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=OQn2omb7e3A3ae-1Gx7GCbIeDvcR020Z9Bn8fuV8qzq6vloqWfVs0e007surFgUyCJbfP5dE7iXSGCPQ4yM]suri_list@y...[/url
> > Sent: Monday, June 23, 2003 6:37 PM
> > To: stamp
> > Subject: [noparse][[/noparse]basicstamps] Output pin glitches
> >
> >
> > I have noticed that the output pin of the stamp
> BSII
> > glitches to low every 2.1 Seconds.
> > The setup is simple: the stamp is powered from a
> > stable 9 Volt power supply. code is simply :
> >
> > high 7
> >
> > when u monitor pin 7 using a non - triggered
> rolling
> > mode of the scope ...a high to low glitch pulse
> every
> > 2.1 seconds occurs.
> > I have heard of someone else having the same
> problem.
> > Kindly advise..i have checked and the stamp does
> not
> > reset so the problem is surely somethings else.
> > what am i missing here?
> > thankyou
> >
> >
> >
> >
> > __________________________________
> > Do you Yahoo!?
> > SBC Yahoo! DSL - Now only $29.95 per month!
> http://sbc.yahoo.com
> >
> > 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/
> >
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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> Text in the Subject and Body of the message will be
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it either :-)
To save power when the Stamp stops it goes into a low power mode. This
stops the watchdog timer which eventually times out and resets the
Stamp. The Stamp resets, all of its pins go to outputs. Quickly, it
realizes that it is stopped on purpose, so it resets its pins to the
last known state and goes back to sleep.
Regards,
Al Williams
AWC
* Control 8 servos at once
http://www.al-williams.com/awce/pak8.htm
>
Original Message
> From: harshit suri [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=06ZgLYpE5US-Z1-eYrZYCZS1J4eN4cKUhzMgPM-Hk57E7NqfgXeIqpPbCmtOBDwdi0Tgdfhb89og]suri_list@y...[/url
> Sent: Monday, June 23, 2003 7:14 PM
> To: basicstamps@yahoogroups.com
> Subject: RE: [noparse][[/noparse]basicstamps] Output pin glitches
>
>
> Thanks AL .it worked but why does that glitch come in
> the first place. seems like a watchdog timer type
> behaviour ..I tried seeing the FAQ . couldnt find the article.
> thankyou
>
>
> --- Al Williams <alw@a...> wrote:
> > Your program is really:
> >
> > High 7
> > End
> >
> > Where the End is implied. TO stop this behavior try
> > this:
> >
> > High 7
> > Endpgm:
> > goto endpgm
> >
> > That should solve your problem. I think there is an
> > article about this
> > at http://www.wd5gnr.com/stampfaq.htm
> >
> >
> > Al Williams
> > AWC
> > * Floating point math for the Stamp, PIC, SX, or any microcontroller
> > http://www.al-williams.com/awce/pak1.htm
> >
> >
> >
> > >
Original Message
> > > From: harshit suri [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=06ZgLYpE5US-Z1-eYrZYCZS1J4eN4cKUhzMgPM-Hk57E7NqfgXeIqpPbCmtOBDwdi0Tgdfhb89og]suri_list@y...[/url
> > > Sent: Monday, June 23, 2003 6:37 PM
> > > To: stamp
> > > Subject: [noparse][[/noparse]basicstamps] Output pin glitches
> > >
> > >
> > > I have noticed that the output pin of the stamp
> > BSII
> > > glitches to low every 2.1 Seconds.
> > > The setup is simple: the stamp is powered from a
> > > stable 9 Volt power supply. code is simply :
> > >
> > > high 7
> > >
> > > when u monitor pin 7 using a non - triggered
> > rolling
> > > mode of the scope ...a high to low glitch pulse
> > every
> > > 2.1 seconds occurs.
> > > I have heard of someone else having the same
> > problem.
> > > Kindly advise..i have checked and the stamp does
> > not
> > > reset so the problem is surely somethings else.
> > > what am i missing here?
> > > thankyou
> > >
> > >
> > >
> > >
> > > __________________________________
> > > Do you Yahoo!?
> > > SBC Yahoo! DSL - Now only $29.95 per month!
> > http://sbc.yahoo.com
> > >
> > > 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/
> > >
> > >
> > >
> >
> >
> > 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/
> >
> >
>
>
> __________________________________________________
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as Mr. Williams has pointed out. In 'Stop', or in
continuous looping, this does not occur.
BTW, you can get around this limitation by adding a
10K or 20K ohm pull-up to +5 volts to the pin in
question. Since the pin briefly becomes an
input (high-impedance), an external pull-up
will hold the value during the watchdog
timeout period.
--- In basicstamps@yahoogroups.com, harshit suri <suri_list@y...>
wrote:
> I have noticed that the output pin of the stamp BSII
> glitches to low every 2.1 Seconds.
> The setup is simple: the stamp is powered from a
> stable 9 Volt power supply. code is simply :
>
> high 7
>
> when u monitor pin 7 using a non - triggered rolling
> mode of the scope ...a high to low glitch pulse every
> 2.1 seconds occurs.
> I have heard of someone else having the same problem.
> Kindly advise..i have checked and the stamp does not
> reset so the problem is surely somethings else.
> what am i missing here?
> thankyou
>
>
>
>
> __________________________________
> Do you Yahoo!?
> SBC Yahoo! DSL - Now only $29.95 per month!
> http://sbc.yahoo.com
high. If the pin is supposed to be low, then the glitch will just go
positive instead of floating.
Al Williams
AWC
* Control 8 servos at once
http://www.al-williams.com/awce/pak8.htm
>
Original Message
> From: Allan Lane [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=9PUoroKS6R2n_48Opg0RMvSdY142O1tSuFidxBd0OXiW6vlhNtoFbYpYM0_neLryIeLJAxH3M2N-p2_Ysw89fWPfl3o]allan.lane@h...[/url
> Sent: Tuesday, June 24, 2003 12:11 PM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Re: Output pin glitches
>
>
> In 'sleep' (or 'end') mode, the BS2's watchdog times out,
> as Mr. Williams has pointed out. In 'Stop', or in
> continuous looping, this does not occur.
>
> BTW, you can get around this limitation by adding a
> 10K or 20K ohm pull-up to +5 volts to the pin in
> question. Since the pin briefly becomes an
> input (high-impedance), an external pull-up
> will hold the value during the watchdog
> timeout period.
>
> --- In basicstamps@yahoogroups.com, harshit suri <suri_list@y...>
> wrote:
> > I have noticed that the output pin of the stamp BSII glitches to low
> > every 2.1 Seconds. The setup is simple: the stamp is powered from a
> > stable 9 Volt power supply. code is simply :
> >
> > high 7
> >
> > when u monitor pin 7 using a non - triggered rolling
> > mode of the scope ...a high to low glitch pulse every
> > 2.1 seconds occurs.
> > I have heard of someone else having the same problem. Kindly
> > advise..i have checked and the stamp does not reset so the problem
> > is surely somethings else. what am i missing here?
> > thankyou
> >
> >
> >
> >
> > __________________________________
> > Do you Yahoo!?
> > SBC Yahoo! DSL - Now only $29.95 per month! http://sbc.yahoo.com
>
>
> 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/
>
>
>
usually use a small capacitor to free-wheel through the reset glitch.
That way it can hold either the low level or the high level briefly
as required and not drain current in the opposite state as does a
pullup/down resistor.
The answer to "why" the glitch occurs is that it is an artifact of
the PIC16C5x that the Stamp is based on, and also the SX28 and SX48
chips that form the multibank enhanced stamps. All resets, including
the watchdog reset, turn the pins to inputs. It is not something
that Parallax added later. Incidentally, the glitch is much shorter
on the BS2pe, 0.25 millisecond instead of 18 milliseconds--that can
be done on the SX48 chip.
(Also, incidentally, more recent PIC chips (16C6x and later) hold
the contents of the direction register through a watchdog reset,
instead of forcing them to inputs.)
-- Tracy
>A pull up resistor will only fix the problem if you intend to leave it
>high. If the pin is supposed to be low, then the glitch will just go
>positive instead of floating.
>
>Al Williams
>AWC
>* Control 8 servos at once
>http://www.al-williams.com/awce/pak8.htm
>
>
>
>>
Original Message
>> From: Allan Lane [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=E4uccUzel794cFeMZcSz46R8791LlqrxswptlNf5vtew8xHH4J5PlVtRArd3jmbd400hcp0j6u4eW9l7RZQ6z4Z2KcCbUw]allan.lane@h...[/url
>> Sent: Tuesday, June 24, 2003 12:11 PM
>> To: basicstamps@yahoogroups.com
>> Subject: [noparse][[/noparse]basicstamps] Re: Output pin glitches
>>
>>
>> In 'sleep' (or 'end') mode, the BS2's watchdog times out,
>> as Mr. Williams has pointed out. In 'Stop', or in
>> continuous looping, this does not occur.
>>
>> BTW, you can get around this limitation by adding a
>> 10K or 20K ohm pull-up to +5 volts to the pin in
>> question. Since the pin briefly becomes an
>> input (high-impedance), an external pull-up
>> will hold the value during the watchdog
>> timeout period.
>>
>> --- In basicstamps@yahoogroups.com, harshit suri <suri_list@y...>
>> wrote:
>> > I have noticed that the output pin of the stamp BSII glitches to low
>
>> > every 2.1 Seconds. The setup is simple: the stamp is powered from a
>> > stable 9 Volt power supply. code is simply :
>> >
>> > high 7
>> >
>> > when u monitor pin 7 using a non - triggered rolling
>> > mode of the scope ...a high to low glitch pulse every
>> > 2.1 seconds occurs.
>> > I have heard of someone else having the same problem. Kindly
>> > advise..i have checked and the stamp does not reset so the problem
>> > is surely somethings else. what am i missing here?
>> > thankyou
>> >
>> >
>> >
>> >
>> > __________________________________
>> > Do you Yahoo!?
>> > SBC Yahoo! DSL - Now only $29.95 per month! http://sbc.yahoo.com
>>
>>
>> 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/
>>
>>
>>
>
>
>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/