Can you run more than one program at the time

Archiver

Hey,

I would like to control a stepper motor with the BS2-IC. At the same
time, when the stepper is running, I want to read some voltages by
using a DAC.

Is this possible. How?

How many voltages can you read per second (samples) and store in the
EEPROM.

Thanks for the help

Archiver

In a message dated 10/19/2003 3:32:54 PM Eastern Standard Time,
drieelot@y... writes:


> I would like to control a stepper motor with the BS2-IC. At the same
> time, when the stepper is running, I want to read some voltages by
> using a DAC.
>

If your stepper motor is running at 200 pulses per sec, each pulse needs to
be around 25us. 200 PPS means a pulse every 5ms. Subtract the pulse width
from it - 25us - and that gives you about 4.9ms to do something else between
pulses. The programming can get a little tricky. If you have an Optascope to
look at your pulse width and the time between pulses, 4.9ms is really a lot of
time to do something else.

What digital value do you want to convert to analog?

Sid

Sid


[noparse][[/noparse]Non-text portions of this message have been removed]

Archiver

Hi,


I'm not sure I totally understand your post.


you want to run a stepper and montior something ? is this for a
feedback control loop ? Not terribly hard to do.

Steppers work (usually) on one pulse is one movement of the
armature. a single step would be on step per pulse with a step being
the distance listed on the nameplate. often 1.8 degrees for 200
steps per revolution. (many many different varieties so be careful)

next, is what are you trying to contorl ? if you are making a
turntable and need to 'adjust' the speed, considder a DC servo motor
(not a hobby servo) as that inplies a feedback for rpm. the DC servo
motor is really just a simple DC motor with feedback. great for
constant or variable speeds.

the stepper is great for single steps.

If you are contorlling a valve and watching the water level, then the
amount of time you are runnng the stepper is so slight, it is easy to
monitor the process, do a PID loop, and then reposistion the motor.

a little more is needed on what you are trying to do.

and as far as memory goes, problably a good idea to make a seperate
post, or is someone replies, to fix the subject line.

Dave

















--- In basicstamps@yahoogroups.com, "Juliano" <drieelot@y...> wrote:
> Hey,
>
> I would like to control a stepper motor with the BS2-IC. At the
same
> time, when the stepper is running, I want to read some voltages by
> using a DAC.
>
> Is this possible. How?
>
> How many voltages can you read per second (samples) and store in
the
> EEPROM.
>
> Thanks for the help

Archiver

Sounds to me like he wants to mount a Sharp sensor with an analog output
on a stepper and have it scan / measure at the same time.

If so, you will probably have to stop the sensor movement each time you
take a reading to get it to work properly. You can use one of those
stepper control chips that requires only step and direction inputs, or
you can use individual transistors to fire each coil in the proper
sequence.

> I'm not sure I totally understand your post.
>
>
> you want to run a stepper and montior something ? is this for a
> feedback control loop ? Not terribly hard to do.
>
> Steppers work (usually) on one pulse is one movement of the
> armature. a single step would be on step per pulse with a step being
> the distance listed on the nameplate. often 1.8 degrees for 200
> steps per revolution. (many many different varieties so be careful)
>
> next, is what are you trying to contorl ? if you are making a
> turntable and need to 'adjust' the speed, considder a DC servo motor
> (not a hobby servo) as that inplies a feedback for rpm. the DC servo
> motor is really just a simple DC motor with feedback. great for
> constant or variable speeds.
>
> the stepper is great for single steps.
>
> If you are contorlling a valve and watching the water level, then the
> amount of time you are runnng the stepper is so slight, it is easy to
> monitor the process, do a PID loop, and then reposistion the motor.
>
> a little more is needed on what you are trying to do.
>
> and as far as memory goes, problably a good idea to make a seperate
> post, or is someone replies, to fix the subject line.