Power Issue (I think)
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Posts: 46,084
Hi, I'm pretty new to the BS and electronics stuff.
I've hooked my stamp (HW board) with 2 motor controllers (Quadruple
Half H-Bridge), controlling 3 motors, and i also hooked up a distance
sensors (GP2D12) with a resistor and a capacitor so that I can use
rctime on it.
Then, when I try to power another distance sensor, everything seems
to stop working. The 1st distance sensor gets random result, and the
motors start going slowly.
My guess is that there's not enough voltage for all the components in
the setup. Can anyone propose a solution?
I've hooked my stamp (HW board) with 2 motor controllers (Quadruple
Half H-Bridge), controlling 3 motors, and i also hooked up a distance
sensors (GP2D12) with a resistor and a capacitor so that I can use
rctime on it.
Then, when I try to power another distance sensor, everything seems
to stop working. The 1st distance sensor gets random result, and the
motors start going slowly.
My guess is that there's not enough voltage for all the components in
the setup. Can anyone propose a solution?
Comments
your motors.
John Baker
http://www.geocities.com/johnsrobotics/
rich2kchan <rich2kchan@y...> wrote:
Hi, I'm pretty new to the BS and electronics stuff.
I've hooked my stamp (HW board) with 2 motor controllers (Quadruple
Half H-Bridge), controlling 3 motors, and i also hooked up a distance
sensors (GP2D12) with a resistor and a capacitor so that I can use
rctime on it.
Then, when I try to power another distance sensor, everything seems
to stop working. The 1st distance sensor gets random result, and the
motors start going slowly.
My guess is that there's not enough voltage for all the components in
the setup. Can anyone propose a solution?
To UNSUBSCRIBE, just send mail to:
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[noparse][[/noparse]Non-text portions of this message have been removed]
batteries.
It isn't a voltage issue as much as a power issue. There are two
possibilities.
1) The motors are causing the voltage to droop because they are drawing so
much current. This causes the Stamp to reset and havoc ensues. Solutions: a)
Bigger capacity power supply; b) Large capacitor from + to - to smooth out
transient brown outs (won't work if you are just sucking the batteries dry
though); c) Separate batteries for motors and electronics (put the ground in
common).
2) The motors are shooting noise back into the electronics and causing a
reset. Solutions: a) Small capacitor across motors; b) Separate batteries;
c) Other noise filtering (for example, chokes in series with motors).
Look at the voltage with a voltmeter. A scope is good for noise. Put an LED
on the Stamp and have it turn on for a second at reset and then back off. If
that LED starts turning on, you are definitely getting a reset.
Hope some of that helps.
Al Williams
AWC
* NEW: Our easiest to use math/analog coprocessor ever!
http://www.awce.com/pak12.htm
Original Message
From: rich2kchan [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=6xDRDQ67bHwcri4p5JuuO55iy96lrIofoXP0Jq2-riyfUgZxdgkD73bbqOWY6hNU21htWgGuAyCWeg]rich2kchan@y...[/url
Sent: Sunday, March 21, 2004 1:17 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Power Issue (I think)
Hi, I'm pretty new to the BS and electronics stuff.
I've hooked my stamp (HW board) with 2 motor controllers (Quadruple
Half H-Bridge), controlling 3 motors, and i also hooked up a distance
sensors (GP2D12) with a resistor and a capacitor so that I can use
rctime on it.
Then, when I try to power another distance sensor, everything seems
to stop working. The 1st distance sensor gets random result, and the
motors start going slowly.
My guess is that there's not enough voltage for all the components in
the setup. Can anyone propose a solution?
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.
Yahoo! Groups Links
Take a look at the datasheets for the things you are using and see how much
current each one requires. Add it all up and compare that to what your stamp
is spec'd to supply. If the former is as much or greater than the latter,
you have power problems.
It would help if you described your circuit more as well. What are you
powering the motors from? How about the sensors? Are the motors 12 volt and
supplied from a wall wart? That sort of thing.
>
Original Message
> From: rich2kchan [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=FpbuJE8f0atqHN2wR7jDBrCJMNwOfm3qqeKVFZ8g6nRfNkC39QmHfn0fOjXigtNJ6EZu7DM7HrpDR85W4Fo]rich2kchan@y...[/url
> Sent: March 21, 2004 11:17 AM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Power Issue (I think)
>
>
>
> Hi, I'm pretty new to the BS and electronics stuff.
>
> I've hooked my stamp (HW board) with 2 motor controllers (Quadruple
> Half H-Bridge), controlling 3 motors, and i also hooked up a distance
> sensors (GP2D12) with a resistor and a capacitor so that I can use
> rctime on it.
>
> Then, when I try to power another distance sensor, everything seems
> to stop working. The 1st distance sensor gets random result, and the
> motors start going slowly.
>
> My guess is that there's not enough voltage for all the components in
> the setup. Can anyone propose a solution?
>
>
>
>
> 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.
>
> Yahoo! Groups Links
>
>
>
>
>
>
The motors have separate power supply (4 AA batteries for 2 of the
motors -- used for wheels -- and a 9V battery for the 3rd motor --
for a 12v dc motor)
The dist. sensor is hooked to the 5v on the board. A 220 ohms
resistor connect an input on the board and the output of the
sensor. A .1 capacitor is hooked from that to the gnd of the
sensor, which is also hooked to the gnd of the board. This is
actually pretty similar to a setup described in the BS manual for a
photoresistor. (in the book whats a microcontroller.)
The setup tried out fine with 1 sensor, and the setup starts getting
messed up as soon as the other sensor is powered.
--- In basicstamps@yahoogroups.com, PatM <pmeloy@s...> wrote:
> Its not the voltage, its the current that is falling behind.
>
> Take a look at the datasheets for the things you are using and see
how much
> current each one requires. Add it all up and compare that to what
your stamp
> is spec'd to supply. If the former is as much or greater than the
latter,
> you have power problems.
>
> It would help if you described your circuit more as well. What are
you
> powering the motors from? How about the sensors? Are the motors 12
volt and
> supplied from a wall wart? That sort of thing.
>
> >
Original Message
> > From: rich2kchan [noparse][[/noparse]mailto:rich2kchan@y...]
> > Sent: March 21, 2004 11:17 AM
> > To: basicstamps@yahoogroups.com
> > Subject: [noparse][[/noparse]basicstamps] Power Issue (I think)
> >
> >
> >
> > Hi, I'm pretty new to the BS and electronics stuff.
> >
> > I've hooked my stamp (HW board) with 2 motor controllers
(Quadruple
> > Half H-Bridge), controlling 3 motors, and i also hooked up a
distance
> > sensors (GP2D12) with a resistor and a capacitor so that I can
use
> > rctime on it.
> >
> > Then, when I try to power another distance sensor, everything
seems
> > to stop working. The 1st distance sensor gets random result,
and the
> > motors start going slowly.
> >
> > My guess is that there's not enough voltage for all the
components in
> > the setup. Can anyone propose a solution?
> >
> >
> >
> >
> > 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.
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
board outputs 50 mA. So then is there any way I can use 2 distance
sensors? How can I increase the current or lower the current used?
--- In basicstamps@yahoogroups.com, "rich2kchan" <rich2kchan@y...>
wrote:
> Sorry for not giving enough details.
> The motors have separate power supply (4 AA batteries for 2 of the
> motors -- used for wheels -- and a 9V battery for the 3rd motor --
> for a 12v dc motor)
> The dist. sensor is hooked to the 5v on the board. A 220 ohms
> resistor connect an input on the board and the output of the
> sensor. A .1 capacitor is hooked from that to the gnd of the
> sensor, which is also hooked to the gnd of the board. This is
> actually pretty similar to a setup described in the BS manual for
a
> photoresistor. (in the book whats a microcontroller.)
> The setup tried out fine with 1 sensor, and the setup starts
getting
> messed up as soon as the other sensor is powered.
>
> --- In basicstamps@yahoogroups.com, PatM <pmeloy@s...> wrote:
> > Its not the voltage, its the current that is falling behind.
> >
> > Take a look at the datasheets for the things you are using and
see
> how much
> > current each one requires. Add it all up and compare that to
what
> your stamp
> > is spec'd to supply. If the former is as much or greater than
the
> latter,
> > you have power problems.
> >
> > It would help if you described your circuit more as well. What
are
> you
> > powering the motors from? How about the sensors? Are the motors
12
> volt and
> > supplied from a wall wart? That sort of thing.
> >
> > >
Original Message
> > > From: rich2kchan [noparse][[/noparse]mailto:rich2kchan@y...]
> > > Sent: March 21, 2004 11:17 AM
> > > To: basicstamps@yahoogroups.com
> > > Subject: [noparse][[/noparse]basicstamps] Power Issue (I think)
> > >
> > >
> > >
> > > Hi, I'm pretty new to the BS and electronics stuff.
> > >
> > > I've hooked my stamp (HW board) with 2 motor controllers
> (Quadruple
> > > Half H-Bridge), controlling 3 motors, and i also hooked up a
> distance
> > > sensors (GP2D12) with a resistor and a capacitor so that I can
> use
> > > rctime on it.
> > >
> > > Then, when I try to power another distance sensor, everything
> seems
> > > to stop working. The 1st distance sensor gets random result,
> and the
> > > motors start going slowly.
> > >
> > > My guess is that there's not enough voltage for all the
> components in
> > > the setup. Can anyone propose a solution?
> > >
> > >
> > >
> > >
> > > 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.
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> > >
> > >
> > >
mA max value.
There are a variety of ways to do this. Some very simple, some still simple
but require a little more thought.
Can you provide the part number and manufacturer of the sensors you are using?
ken
It looks like the distance sensor typically takes in 33 mA and the
board outputs 50 mA. So then is there any way I can use 2 distance
sensors? How can I increase the current or lower the current used?
[noparse][[/noparse]Non-text portions of this message have been removed]
The specs can be found here:
http://www.junun.org/MarkIII/datasheets/GP2D12_15.pdf
--- In basicstamps@yahoogroups.com, smartdim@a... wrote:
> It will be very easy to "drive" your sensors without exceeding the
stamp 50
> mA max value.
>
> There are a variety of ways to do this. Some very simple, some
still simple
> but require a little more thought.
>
> Can you provide the part number and manufacturer of the sensors
you are using?
>
> ken
>
>
>
>
>
> It looks like the distance sensor typically takes in 33 mA and the
> board outputs 50 mA. So then is there any way I can use 2
distance
> sensors? How can I increase the current or lower the current used?
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
How are you currently powering the sensors? For the sensors, what is the Vcc
5V pin connected to? Is is connected to one of the I/O pins (P0 ~ P15)?
The stamp manual specifies the current limit with regard to the I/O pins, but
does not specifically address the current limits when using pin 21, the
output of the Stamp on-board 5 volt regulator. It is possible you can run the
sensors from pin 21, but to be safe.......
What I would do is the following:
Get a 7805 voltage regulator with the TO-220 package
http://cache.national.com/ds/LM/LM341.pdf
On the input to ground, and the output to ground, connect a 10 to 50 uF
capacitor and a 0.1 microfarad capacitor.
Connect the output of the regulator directly to pin 21 (VDD) of the stamp.
The output of this regulator will now become the power supply for your stamp,
and for your sensors.
Write back if this does not make sense.
Note to Jon Williams.......what is the maximum current output of the Stamp
on-board regulator? I assume the total 40mA source or 50mA sink from the I/O
pins is primarily a function of the on-board pic? And if so, how much current is
left over for the pin 21 output?
For the moment lets ignore the power dissapation of the on-board regulator.
I used the sharp GP2D12 distance sensors.
The specs can be found here:
http://www.junun.org/MarkIII/datasheets/GP2D12_15.pdf
[noparse][[/noparse]Non-text portions of this message have been removed]
the sensors you use -- probably not practical.
You can easily increase the current available.
Add a 7805 linear regulator to your project,
or even better a LM2940 low-dropout regulator.
These should be good to 1 amp.
--- In basicstamps@yahoogroups.com, "rich2kchan" <rich2kchan@y...>
wrote:
>
> It looks like the distance sensor typically takes in 33 mA and the
> board outputs 50 mA. So then is there any way I can use 2 distance
> sensors? How can I increase the current or lower the current used?
>
>
> --- In basicstamps@yahoogroups.com, "rich2kchan" <rich2kchan@y...>
> wrote:
> > Sorry for not giving enough details.
> > The motors have separate power supply (4 AA batteries for 2 of
the
> > motors -- used for wheels -- and a 9V battery for the 3rd motor --
> > for a 12v dc motor)
> > The dist. sensor is hooked to the 5v on the board. A 220 ohms
> > resistor connect an input on the board and the output of the
> > sensor. A .1 capacitor is hooked from that to the gnd of the
> > sensor, which is also hooked to the gnd of the board. This is
> > actually pretty similar to a setup described in the BS manual for
> a
> > photoresistor. (in the book whats a microcontroller.)
> > The setup tried out fine with 1 sensor, and the setup starts
> getting
> > messed up as soon as the other sensor is powered.
> >
> > --- In basicstamps@yahoogroups.com, PatM <pmeloy@s...> wrote:
> > > Its not the voltage, its the current that is falling behind.
> > >
> > > Take a look at the datasheets for the things you are using and
> see
> > how much
> > > current each one requires. Add it all up and compare that to
> what
> > your stamp
> > > is spec'd to supply. If the former is as much or greater than
> the
> > latter,
> > > you have power problems.
> > >
> > > It would help if you described your circuit more as well. What
> are
> > you
> > > powering the motors from? How about the sensors? Are the motors
> 12
> > volt and
> > > supplied from a wall wart? That sort of thing.
> > >
> > > >
Original Message
> > > > From: rich2kchan [noparse][[/noparse]mailto:rich2kchan@y...]
> > > > Sent: March 21, 2004 11:17 AM
> > > > To: basicstamps@yahoogroups.com
> > > > Subject: [noparse][[/noparse]basicstamps] Power Issue (I think)
> > > >
> > > >
> > > >
> > > > Hi, I'm pretty new to the BS and electronics stuff.
> > > >
> > > > I've hooked my stamp (HW board) with 2 motor controllers
> > (Quadruple
> > > > Half H-Bridge), controlling 3 motors, and i also hooked up a
> > distance
> > > > sensors (GP2D12) with a resistor and a capacitor so that I
can
> > use
> > > > rctime on it.
> > > >
> > > > Then, when I try to power another distance sensor, everything
> > seems
> > > > to stop working. The 1st distance sensor gets random result,
> > and the
> > > > motors start going slowly.
> > > >
> > > > My guess is that there's not enough voltage for all the
> > components in
> > > > the setup. Can anyone propose a solution?
> > > >
> > > >
> > > >
> > > >
> > > > 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.
> > > >
> > > > Yahoo! Groups Links
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >