multiple stepper motors
Archiver
Posts: 46,084
I want to control three stepper motors initially, (leading to
twelve!). Which is the best way to go?
Can I cascade multiple shift registers
Should I use stepper driver chips - but then I'll still run out of
i/o lines?
How about running stepper driver chips from shift registers?
There will be times when all the motors will need to work
simultaneously, so I'm a little concerned about programming.
Can anyone suggest any examples? Either of circuits or programming.
(Preferably both! Don't want much....)
I've managed to get the first motor running okay, so I'm okay on
driving it, but the rest is a little scary.
Power isn't an issue.
If this is picked up by Dave Mucha? Is there any printed information
where I can read up on some of the stuff you've been posting to the
group. It's fascinating, but a little over my head at the moment.
Many thanks.
Howard
twelve!). Which is the best way to go?
Can I cascade multiple shift registers
Should I use stepper driver chips - but then I'll still run out of
i/o lines?
How about running stepper driver chips from shift registers?
There will be times when all the motors will need to work
simultaneously, so I'm a little concerned about programming.
Can anyone suggest any examples? Either of circuits or programming.
(Preferably both! Don't want much....)
I've managed to get the first motor running okay, so I'm okay on
driving it, but the rest is a little scary.
Power isn't an issue.
If this is picked up by Dave Mucha? Is there any printed information
where I can read up on some of the stuff you've been posting to the
group. It's fascinating, but a little over my head at the moment.
Many thanks.
Howard
Comments
Which stamp?, stepper driver chips?
David
In basicstamps@yahoogroups.com, "howgreen2003" <greenhf@l...> wrote:
> I want to control three stepper motors initially, (leading to
> twelve!). Which is the best way to go?
> Can I cascade multiple shift registers
> Should I use stepper driver chips - but then I'll still run out of
> i/o lines?
> How about running stepper driver chips from shift registers?
>
> There will be times when all the motors will need to work
> simultaneously, so I'm a little concerned about programming.
>
> Can anyone suggest any examples? Either of circuits or programming.
> (Preferably both! Don't want much....)
>
> I've managed to get the first motor running okay, so I'm okay on
> driving it, but the rest is a little scary.
>
> Power isn't an issue.
>
> If this is picked up by Dave Mucha? Is there any printed information
> where I can read up on some of the stuff you've been posting to the
> group. It's fascinating, but a little over my head at the moment.
>
> Many thanks.
>
> Howard
wrote:
> I want to control three stepper motors initially, (leading to
> twelve!). Which is the best way to go?
> Can I cascade multiple shift registers
> Should I use stepper driver chips - but then I'll still run out of
> i/o lines?
> How about running stepper driver chips from shift registers?
>
> There will be times when all the motors will need to work
> simultaneously, so I'm a little concerned about programming.
>
> Can anyone suggest any examples? Either of circuits or programming.
> (Preferably both! Don't want much....)
>
> I've managed to get the first motor running okay, so I'm okay on
> driving it, but the rest is a little scary.
>
> Power isn't an issue.
>
> If this is picked up by Dave Mucha? Is there any printed
information
> where I can read up on some of the stuff you've been posting to the
> group. It's fascinating, but a little over my head at the moment.
>
> Many thanks.
>
> Howard
Hi Howard,
first question is how much power do you plan to use ? It is always
an issue. Each motor may be less than 1 amp, but 12 ? sounds like a
nice project !
considder that the Stamp is the controller and you need a stepper
driver. this can be as simple as a 74hc194 and transistors for the
power. That would let you select the voltage for motor for each
motor. great if you have mixed voltage motors.
second that would need one pulse output for each motor to make steps
and one direction pin for each motor. unless you use a serial output
to another chip, or some other way to expand the outputs, the 2 pins
per motor is needed. (not much help there)
If you want more power, the need to work in a chopper driver will
allow you to get a LOT more power out of each motor instead of
running motors at nameplate voltage.
the difference is that a full power ON to a coil can only be
nameplate amps and volts. a chopper monitors the line and chops the
power to deliver the proper watts to the motor. higer voltage
delivers higher performance.
Allegro has bi-polar stepper driver chips, A3977 35 volts, 2.5 amps
will make your 1.5 volt, 2 amp motor zing ! (still need one step and
one direction pin)
The logic to fire the coils on a stepper is to fire each coil
seperatly. if you connect a set of 4 darlington outputs to the
Stamp, you use 4 pins and control direction by software. high amp,
single channel darlingtons like the TIP120 are more common for motors.
regardless how you do it, considder using a seperate power supply,
the motors switching all that power will be noisy!
The one thing I would recomend is to forget unipolar wiring, the
current resistor will chew up a lot of power when you are using that
many motors. if you are not worried about power, maybe heat will get
your attention. do a calc on watts.
And, if you are not trying to get high speeds from the motors, series
wire the coils. (isolate the center tap) that requires one half the
current to get the same power at lower speeds.
As far as multiple units running at the same time, that reduces
outputs only if they always run at the same speed and same direction.
a little lint in the axel and what once ran straght and true does a
lot of left turns.
Dave
very little of it was.
I've bought a BS2 and Board of education. Also downloaded Stampworks
from Parallax. The project to run a single stepper is in that. All
I've done is modify the program ever so slightly.
However, there is still enough space on the BS2 to run a second
stepper in the same manner. But that's all. Hence my need for
expansion.
Just to explain if you're using a Stamp powered a different way. The
BS2 is only powered by a 9V battery, regulated to 5 volts on the
B.O.E. All other components are on a separate prototye board which
had a regulated 12 power supply attached to it. That was what was
driving the stepper.
Incidentally, my project is to run what is essentially a fruit
machine/one armed bandit type mechanism, but instead of the reels
displaying fruits etc. it will have rubber stamps attached to the
reels. This is all because the outfit I work for is composed of
technophobes who think it's a good idea to have a man manually
stamping the product as it comes off the production line!
The initial objective is to get the first three motors able to go
from 1 to 999. Then once the technophobes know it's a feasible
project, they'll invest in extra hardware and add the additional
resources to enable the product code to also be rubber stamped
automatically.
Regards,
Howard.
--- In basicstamps@yahoogroups.com, "photo1869" <David@C...> wrote:
> --- I'm after two steppers. Tell me how you got the fisrt one going.
> Which stamp?, stepper driver chips?
>
> David
>
> In basicstamps@yahoogroups.com, "howgreen2003" <greenhf@l...> wrote:
> > I want to control three stepper motors initially, (leading to
> > twelve!). Which is the best way to go?
> > Can I cascade multiple shift registers
> > Should I use stepper driver chips - but then I'll still run out
of
> > i/o lines?
> > How about running stepper driver chips from shift registers?
> >
> > There will be times when all the motors will need to work
> > simultaneously, so I'm a little concerned about programming.
> >
> > Can anyone suggest any examples? Either of circuits or
programming.
> > (Preferably both! Don't want much....)
> >
> > I've managed to get the first motor running okay, so I'm okay on
> > driving it, but the rest is a little scary.
> >
> > Power isn't an issue.
> >
> > If this is picked up by Dave Mucha? Is there any printed
information
> > where I can read up on some of the stuff you've been posting to
the
> > group. It's fascinating, but a little over my head at the moment.
> >
> > Many thanks.
> >
> > Howard
driver chips and multiple stamps -- about 3 motors per stamp. If you
are sending command signals from a PC to your stamp, just send them to
all the stamps simultaneously, and sort out the control logic at each
stamp. If the motors don't really have to run simultaneously, reduce
the number of stamps by using DPDT relays at the ouputs of bipolar
drivers, and switch the relays with stamps driving ULN2003 chips driving
the relays. This works -- I've done it.
Dennis
Original Message
From: howgreen2003 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=hg4oolnCa0UEzuQN1UgQbnJRfFpwOPioZMlSdVvNOrXmGpwXM0Nik23OIn0g-mOi7E4TuTWbe_zJ4Af7yg]greenhf@l...[/url
Sent: Thursday, August 14, 2003 1:56 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] multiple stepper motors
I want to control three stepper motors initially, (leading to
twelve!). Which is the best way to go?
Can I cascade multiple shift registers
Should I use stepper driver chips - but then I'll still run out of
i/o lines?
How about running stepper driver chips from shift registers?
There will be times when all the motors will need to work
simultaneously, so I'm a little concerned about programming.
Can anyone suggest any examples? Either of circuits or programming.
(Preferably both! Don't want much....)
I've managed to get the first motor running okay, so I'm okay on
driving it, but the rest is a little scary.
Power isn't an issue.
If this is picked up by Dave Mucha? Is there any printed information
where I can read up on some of the stuff you've been posting to the
group. It's fascinating, but a little over my head at the moment.
Many thanks.
Howard
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/
> machine/one armed bandit type mechanism, but instead of the reels
> displaying fruits etc. it will have rubber stamps attached to the
> reels. This is all because the outfit I work for is composed of
> technophobes who think it's a good idea to have a man manually
> stamping the product as it comes off the production line!
>
> The initial objective is to get the first three motors able to go
> from 1 to 999. Then once the technophobes know it's a feasible
> project, they'll invest in extra hardware and add the additional
> resources to enable the product code to also be rubber stamped
> automatically.
If you are using the steppers to spin the counters for a serial
number type of marker, you should be able to use a shift register to
select which motor gets a signal, and sequence each motor so each
motor would get a command, move and switch to the next. that would
reduce the pin count considderably.
you cannot do something like move an X/Y table and a drill/mill with
this sort of connection. those require simultaneous moves.