trying to make a laser show
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Posts: 46,084
I am trying to make a laser show design using the basic controller. and
i am looking for some ideas on controlling some motors. i would like to
control the speed, direction,and on and off mode. Of up to 3 motors, and
one laser beam, i want everything controlled non of me moving konbs and
stuff. On my controller i have 1 grd, 1 vcc, and 16 points, are they
digital or antolog? well if you can help me it would be help full.
thanks Justin
i am looking for some ideas on controlling some motors. i would like to
control the speed, direction,and on and off mode. Of up to 3 motors, and
one laser beam, i want everything controlled non of me moving konbs and
stuff. On my controller i have 1 grd, 1 vcc, and 16 points, are they
digital or antolog? well if you can help me it would be help full.
thanks Justin
Comments
5 1/4" floppy drives and Allegro ULN5804 driver chips. I can e-mail
you schematics if you are interested.
Carl
--- In basicstamps@egroups.com, Justin Yagoda <AbsoluteZero@w...>
wrote:
> I am trying to make a laser show design using the basic controller.
and
> i am looking for some ideas on controlling some motors. i would
like to
> control the speed, direction,and on and off mode. Of up to 3
motors, and
> one laser beam, i want everything controlled non of me moving konbs
and
> stuff. On my controller i have 1 grd, 1 vcc, and 16 points, are they
> digital or antolog? well if you can help me it would be help full.
>
> thanks Justin
cmaness@e... wrote:
> I have designed and built this project. I used stepper motors from
> 5 1/4" floppy drives and Allegro ULN5804 driver chips. I can e-mail
> you schematics if you are interested.
> Carl
>
> --- In basicstamps@egroups.com, Justin Yagoda <AbsoluteZero@w...>
> wrote:
> > I am trying to make a laser show design using the basic controller.
> and
> > i am looking for some ideas on controlling some motors. i would
> like to
> > control the speed, direction,and on and off mode. Of up to 3
> motors, and
> > one laser beam, i want everything controlled non of me moving konbs
> and
> > stuff. On my controller i have 1 grd, 1 vcc, and 16 points, are they
> > digital or antolog? well if you can help me it would be help full.
> >
> > thanks Justin
will convert them to .PDF's and post them on my webspace with some
pictures as soon as I have time. It uses two stepper motors mounted
X-Y to point a double-ended laser diode assembly. In other words, it
is an automated laser pointer, it is not really fast enough to be
called a laser "show". I have thought about a three motor setup to
drive mirrors and this same type of setup could probably be used to
create Lissajous patterns and whatnot.
See http://www.mi-lasers.com/index1.html for some ideas.
--- In basicstamps@egroups.com, Justin Yagoda <AbsoluteZero@w...>
wrote:
> yes please and any pics you may have
>
terrible vibration problems and they do not provide acceptible resolution.
Try looking at Galvonometers. You can attempt to stabalize the mirrors but
it is best to go with a galvo solution. Hope this helps. Galvos are also
better for 'rounded' patterns as they are linear.
MH
Original Message
From: <cmaness@e...>
To: <basicstamps@egroups.com>
Sent: Thursday, November 16, 2000 12:57 PM
Subject: [noparse][[/noparse]basicstamps] Re: trying to make a laser show
> I have received several requests. The schematics are in OrCad and I
> will convert them to .PDF's and post them on my webspace with some
> pictures as soon as I have time. It uses two stepper motors mounted
> X-Y to point a double-ended laser diode assembly. In other words, it
> is an automated laser pointer, it is not really fast enough to be
> called a laser "show". I have thought about a three motor setup to
> drive mirrors and this same type of setup could probably be used to
> create Lissajous patterns and whatnot.
>
> See http://www.mi-lasers.com/index1.html for some ideas.
>
>
>
> --- In basicstamps@egroups.com, Justin Yagoda <AbsoluteZero@w...>
> wrote:
> > yes please and any pics you may have
> >
>
>
>
>
>
order to get my laser pointer to move smoothly I have to slow it
*way* down to a speed well below where there is any kind of
persistence effect. Galvos are definitely the way to go.
--- In basicstamps@egroups.com, "Michael Hendricks" <mjh80@b...>
wrote:
> I have played around with this in the past. Steppers tend to shake
and cause
> terrible vibration problems and they do not provide acceptible
resolution.
> Try looking at Galvonometers. You can attempt to stabalize the
mirrors but
> it is best to go with a galvo solution. Hope this helps. Galvos are
also
> better for 'rounded' patterns as they are linear.
>
> MH
might be acceptable depending on your approach and application.
I built a laser-diode beam steering system which rotates two 10-deg wedge
prisms, each with a 1.8 degree stepper. The visible beam passes through both
prisms and is then deflected out by a "hot" mirror (one that absorbs IR and
reflects visible). My main goal was a linear sinusoidal beam tracking
stimulus for human eye pursuit tracking, with amplitude 20 deg and frequency
of 0.5 Hz. The prisms face each other, glued to stepper shafts. When the
prisms counter-rotate, there is a direct polar to linear conversion which
generates a linear sinusoid. By turning the prisms 90 degrees, the
deflection can be either horizontal or vertical. A full period is 200 steps,
with actual frequency determined by the delay between pulses. A single BS1
was used, driving a ULN2003 for each motor, by modifying the stepper program
in the BS1 manual. There is some barely noticable jerk between steps at
zero-crossings, but it is small and fast enough to serve as a single moving
spot for the visual pursuit system. At the sinusoid peaks, points are so
close together that the jerk is not discernable at all. Vibration-damping
material from McMaster & Carr took care of stepper vibrations, when the
stepper frame was mounted in a metal box. The fun part was figuring out the
physics of varying the delay to produce 1) a sinusoid at half the amplitude,
and 2) a triangular beam waveform. That took a few long sessions running
Matlab. I solved both, carefully programmed them for the BS1, and then
received the dreaded "out of EPROM" message. Oh well ... fun while it
lasted. I'm now reprogramming it all in C for use with a PIC. The advantage
of prototyping with a BS1 was that I could try this approach out while
recording human eye movements, and verify that the eye movement responses
were sinusoidal.
Another advantage of this approach for my application: beam deflection is
automatically "calibrated" in degrees of visual space by the known stepper
angles, independent of the distance to the display screen. That wouldn't be
true of a galvo-based system. Sure, I could have used galvos, but they cost
about a factor of 10 more than two steppers from Jameco plus 2 wedge prisms
from an optical house.
Dennis
Original Message
From: Michael Hendricks [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=40MkSIYTImjYwW76jnOuhP3yxmWicoXMKV8YLwNBzbDo9LGTF6VOWQAzqcf5toJuob1GyFj2dw]mjh80@b...[/url
Sent: Thursday, November 16, 2000 10:12 AM
To: basicstamps@egroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Re: trying to make a laser show
I have played around with this in the past. Steppers tend to shake and cause
terrible vibration problems and they do not provide acceptible resolution.
Try looking at Galvonometers. You can attempt to stabalize the mirrors but
it is best to go with a galvo solution. Hope this helps. Galvos are also
better for 'rounded' patterns as they are linear.
MH
Original Message
From: <cmaness@e...>
To: <basicstamps@egroups.com>
Sent: Thursday, November 16, 2000 12:57 PM
Subject: [noparse][[/noparse]basicstamps] Re: trying to make a laser show
> I have received several requests. The schematics are in OrCad and I
> will convert them to .PDF's and post them on my webspace with some
> pictures as soon as I have time. It uses two stepper motors mounted
> X-Y to point a double-ended laser diode assembly. In other words, it
> is an automated laser pointer, it is not really fast enough to be
> called a laser "show". I have thought about a three motor setup to
> drive mirrors and this same type of setup could probably be used to
> create Lissajous patterns and whatnot.
>
> See http://www.mi-lasers.com/index1.html for some ideas.
>
>
>
> --- In basicstamps@egroups.com, Justin Yagoda <AbsoluteZero@w...>
> wrote:
> > yes please and any pics you may have
> >
>
>
>
>
>
that,and where can i get it?
"Dennis P. O'Leary" wrote:
> Regarding stepper motor shake, vibration, and poor resolution, they still
> might be acceptable depending on your approach and application.
> I built a laser-diode beam steering system which rotates two 10-deg wedge
> prisms, each with a 1.8 degree stepper. The visible beam passes through both
> prisms and is then deflected out by a "hot" mirror (one that absorbs IR and
> reflects visible). My main goal was a linear sinusoidal beam tracking
> stimulus for human eye pursuit tracking, with amplitude 20 deg and frequency
> of 0.5 Hz. The prisms face each other, glued to stepper shafts. When the
> prisms counter-rotate, there is a direct polar to linear conversion which
> generates a linear sinusoid. By turning the prisms 90 degrees, the
> deflection can be either horizontal or vertical. A full period is 200 steps,
> with actual frequency determined by the delay between pulses. A single BS1
> was used, driving a ULN2003 for each motor, by modifying the stepper program
> in the BS1 manual. There is some barely noticable jerk between steps at
> zero-crossings, but it is small and fast enough to serve as a single moving
> spot for the visual pursuit system. At the sinusoid peaks, points are so
> close together that the jerk is not discernable at all. Vibration-damping
> material from McMaster & Carr took care of stepper vibrations, when the
> stepper frame was mounted in a metal box. The fun part was figuring out the
> physics of varying the delay to produce 1) a sinusoid at half the amplitude,
> and 2) a triangular beam waveform. That took a few long sessions running
> Matlab. I solved both, carefully programmed them for the BS1, and then
> received the dreaded "out of EPROM" message. Oh well ... fun while it
> lasted. I'm now reprogramming it all in C for use with a PIC. The advantage
> of prototyping with a BS1 was that I could try this approach out while
> recording human eye movements, and verify that the eye movement responses
> were sinusoidal.
> Another advantage of this approach for my application: beam deflection is
> automatically "calibrated" in degrees of visual space by the known stepper
> angles, independent of the distance to the display screen. That wouldn't be
> true of a galvo-based system. Sure, I could have used galvos, but they cost
> about a factor of 10 more than two steppers from Jameco plus 2 wedge prisms
> from an optical house.
> Dennis
>
>
Original Message
> From: Michael Hendricks [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Lk0A0RHsx2PdAvlD4jgdLAKhGHJVoE1AWNAQ4yc9-WV7xEZ0QKRGe6uQDymO2yW8MsZG8DIoKqCX]mjh80@b...[/url
> Sent: Thursday, November 16, 2000 10:12 AM
> To: basicstamps@egroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] Re: trying to make a laser show
>
> I have played around with this in the past. Steppers tend to shake and cause
> terrible vibration problems and they do not provide acceptible resolution.
> Try looking at Galvonometers. You can attempt to stabalize the mirrors but
> it is best to go with a galvo solution. Hope this helps. Galvos are also
> better for 'rounded' patterns as they are linear.
>
> MH
>
>
Original Message
> From: <cmaness@e...>
> To: <basicstamps@egroups.com>
> Sent: Thursday, November 16, 2000 12:57 PM
> Subject: [noparse][[/noparse]basicstamps] Re: trying to make a laser show
>
> > I have received several requests. The schematics are in OrCad and I
> > will convert them to .PDF's and post them on my webspace with some
> > pictures as soon as I have time. It uses two stepper motors mounted
> > X-Y to point a double-ended laser diode assembly. In other words, it
> > is an automated laser pointer, it is not really fast enough to be
> > called a laser "show". I have thought about a three motor setup to
> > drive mirrors and this same type of setup could probably be used to
> > create Lissajous patterns and whatnot.
> >
> > See http://www.mi-lasers.com/index1.html for some ideas.
> >
> >
> >
> > --- In basicstamps@egroups.com, Justin Yagoda <AbsoluteZero@w...>
> > wrote:
> > > yes please and any pics you may have
> > >
> >
> >
> >
> >
> >
>What do i use to control the stepper motors, I have a bs2, what do i
connect to
>that,and where can i get it?
Here's a great rundown on using a L293D driver to control steppers with a BS2:
http://www.seattlerobotics.org/encoder/may98/steppers.html
This will work with small-ish bipolar steppers. An even better chip is TI's
SN754410NE. Identical pinout but can handle 1A vs. 600Ma for the L293D.
Best, Duncan
motor with only 2 pins.
Dennis
Original Message
From: Justin Yagoda [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=9AE2w-t96fhCXCsjrhUzInEEsHTrua4M2mdbnrg2deFfzk-vlyfWve37KA_Ehx42pLwCmp_3LiA6Bht6l4EMjH4RoASz_EkA]AbsoluteZero@w...[/url
Sent: Thursday, November 16, 2000 9:33 PM
To: basicstamps@egroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Re: trying to make a laser show
What do i use to control the stepper motors, I have a bs2, what do i connect
to
that,and where can i get it?
http://www.users.qwest.net/~cmaness/
--- In basicstamps@egroups.com, Justin Yagoda <AbsoluteZero@w...>
wrote:
> What do i use to control the stepper motors, I have a bs2, what do
i connect to
> that,and where can i get it?
>I had thought about the vibration issue and I'm sure your right. In
>order to get my laser pointer to move smoothly I have to slow it
>*way* down to a speed well below where there is any kind of
>persistence effect. Galvos are definitely the way to go.
Justin -
A simple setup for a hobbyist is contained in a kit - offered by Herbach and
Rademen [noparse][[/noparse] http://www.herbach.com ]. It usually appears near the end of the
printed catalog, or if you use their Online Catalog, click on the section marked
"Spirograph Kit". The list is alphabetically ordered.
The kit contains 3 x low voltage, low amperage stepper motors with shaft-mounted
face mirrors. The laser device (not included) is pointed towards one of the
motorized mirrors. Then the other two elements (galvos) are positioned at 90
degrees (each) from the path of the beam - which is reflected from the first:
Spirograph Kit
\ /
\ \
laser beam =====>\7\ motor #1
|\ \__
| \
__ \ | \ /
\ \v \ \
motor #2 \7\===========>\7\ motor #3
\ \ |\ \__
/ \ | \
|
v
PATTERNS
on the wall
The Cat. # is TMR92LSR2189 and the cost is $27.50 US . They're nice folks to
deal with.
You must supply all of the Stamp related items, as well as the driver chips
(mentioned by others) and batteries, or provide a battery eliminator (your
choice). The motors operate from .5VDC to 6.0VDC and each has a 1.25" mirror
fixture attached to the shaft. A single motor kit is also available so you can
start out small. The single motor kit is Cat. # TM92LSR2052 at a cost of $5.00
US making it an inexpensive way to start.
Hope that helps to get you started.
Regards,
Bruce Bates