Arduino Stepper Motor

I am currently using the arduino stepper motor example to control a stepper motor from sparkfun with an easy driver. The example works perfectly on the first run, however when I press the stop button and try running it again, i have to change the stepper motor number to make the stepper motor work again. I avoid using the abort button, as that can cause problems since the arduino is not completely closing off all its programs.
Can someone explain why this is happening? Thank you.

So you are controlling the Arduino via LV right?
To give any kind of meaningful answer we really need to see some code...
Mike...
Certified Professional Instructor
Certified LabVIEW Architect
LabVIEW Champion
"... after all, He's not a tame lion..."
Be thinking ahead and mark your dance card for NI Week 2015 now: TS 6139 - Object Oriented First Steps

Similar Messages

Stepper motors to move antenna

Hello !
My name is Paul, I am from Romania.
I need some ideas on how to make a project.
I need to control a fake antenna (I am saying fake because it won't be attached to anything, just for display purposes) using LabView.
The antenna will be very small (about 15cm in diameter and made from light materials) so I won't need powerfull motors. I was thinking about hooking up 2 stepper motors (maybe from a printer) to some sort of controll board and to a PC with LabView. The antenna needs to move 360 degrees on a round base and 180 degrees of elevation.
I found a video on youtube that is a lot more complicated and a lot heavier than what I need, but should give you a better perspective of what I am talking about.
http://www.youtube.com/watch?v=vihdaseWNQw
I need the cheapest way possible (because I am on my own budget).
Thank you !
Solved!
Go to Solution.
Attachments:
antenna_base.jpg ‏201 KB

I drew a quick sketch hoping you will understand better what I'm trying to do. I only connected one stepper motor for a test run. I opened the "Arduino Stepper Motor.vi" in LabView and tested on stepper motor 1. It didn't move (but maybe I didn't set it up correctly in labview). The setup was made exactly as the picture I attached.
The stepper motor 1 (which controls elevation) has to move the antenna 90 degrees. So I'm guesing I have to divide the 90 degrees to 1.8 degrees (the motors deg/step) to find out how many steps I need in total. And the same for stepper motor 2 (360 / 1.8).
So I need a .vi that automaticaly transforms the degrees which you set the elevation and azimuth to steps for the stepper motors. And when I press "Start" the two motors move to the desired position. I also need a "Reset" button to automaticaly come back to the original position (which will be 0 degrees azimuth and 0 degrees elevation - let's say the magnetic north) each time I run the program.
Attachments:
setup.jpg ‏1120 KB
setup_drawing.jpg ‏1102 KB
EasyDriver-Stepper-Motor-Driver2.png ‏50 KB

Robotics-Running two stepper motors

Hi
I am working with LIFA (labview interface for arduino) to run two stepper motors to create a special (simple) path on XY plane. The example code (Arduino Stepper Motor.vi) works fine with one motor, but I don't know how I can modify it so that two motors can move with one time pushing the button, one after another while taking turns. Any Ideas?
The motion plan is as follows: 1. Motor 2 is stationary and motor 1 moves the load for 100 steps in X direction, then it stops and motor 2 starts to move the load for 70 steps in Y direction.
2. The same as 1, only the direction of motor 1 motion is reversed, and motor 2 moves 85 steps instead of 70 in the same direction.
3. Repetition of 1 and 2 for 4 times with different number of steps at each level.
I have twe big easy drivers, and one Arduino Uno.
I truly appreciate your help,
Best,
Ashkan

You could create a state machine.
You could create a movement recipe where you enter in each sequential movement, and the code steps through the recipe one movement at a time.
You could create some combination of 1 and 2.
How do you want it to work? Are these steps going to remain constant, or do you want to be able to change them from one run to the next? How much do you know about LV? Have you any code that you wrote? What is the long term goal -- are you building towards something specific or just learning for the sake of learning?
Mike...
Certified Professional Instructor
Certified LabVIEW Architect
LabVIEW Champion
"... after all, He's not a tame lion..."
Be thinking ahead and mark your dance card for NI Week 2015 now: TS 6139 - Object Oriented First Steps

Using LabView, Arduino, and Easy-Driver to control a Stepper Motor

Hello fair folks of the LabView forums!
I am a humble engineering student in need of some advice and input on a project I am working on.
I’ve also done a fair amount of reading on the LabView forums with people trying to use LabView and Arduino to control stepper motors, and I’ve used as much information from each as I could. However the problem I'm encountering now is one which is unique to my VI Configuration.
So, here is what has been done thus far:
-Installed LabView Interface for Arduino [LIFA]
-Installed necessary VISA drivers for LabView to communicate with arduino
-Uploaded firmware to Arduino to allow it to communicate with LabView
-Properly wired Stepper Motor with Easy Driver and Power Supply; I have verified this by first using the Arduino independently of LabView, using example code found here.
-I have created a VI, and have just recently got it to run without reporting back any errors. While I suspect the behavior I’m encountering has to do with something inside the VI, it is difficult to determine as there are no errors being reported!
But here is general problem I am encountering:
-Connect Joystick to USB Port, connect Arduino to USB Port.
-Plug in outlet for Power Supply
-Open LabView VI
-Run LabView VI
-LabView successfully detects Joystick, and Arduino.
-Tilt Joystick; Stepper Motor moves in proper direction, but it only takes a single step. If held, it does not move further. If returned to zero, and then tilted, it again only takes a single step.
I know that in the example code, the Arduino issued the step command by writing the signal from LOW to HIGH, and varied the speed by how often it did this.
I assumed that the Write-PWM feature would do this same thing, but perhaps my assumption is wrong. I will continue to tinker with this myself, but I would be extremely grateful for any insight you might be able to lend.
I’m thinking, if not the Arduino Write-PMW feature perhaps a simple timing-sequence that could be used to alternate between writing 0 and 1, with the timescale of the sequence being scaled to the X-Axis from the Joystick. But, I am open to suggestions, and certainly appreciate any thoughts you may have to offer!
Attached to this is the VI used in this setup, a picture of said VI, as well as a rough sketch of the hardware configuration.
Thank you!
Attachments:
Arduino Stepper Control.vi ‏1224 KB
VI Picture.png ‏82 KB
Configuration Sketch.png ‏522 KB

Hi danjifraga,
I am not so familiar with the Arduino toolkit functions, but you may have better luck looking at the Arduino page at:
www.ni.com/arduino
I'll ask around on Monday to see if anyone is more familiar with the toolkit.
Good luck,
Brian
Brian G.

How do you control LED lights on the front panel to identify the number of steps a stepper motor has taken?

I am controlling a stepper motor that is coupled with a valve with four outlets (using an Arduino). I've got a general understanding of how to control the motor, but I want LED lights on the front panel to light up that indicate which outlet the valve is currently at after the steps are taken. The method I'm thinking about involves a lot of repetitive code. I'm not that experienced with LabVIEW, I'm assuming I need some sort of loop structure but I don't know how to set it up in order to control the sequence of the LEDs. I've attached my current block diagram for a visual aid if needed.
Attachments:
Capture.JPG ‏33 KB

I was thinking about using the Stepper To Go and Stepper Write functions four separate times, using the same constants for the steps each time since the distance between each outlet is equivalent. The only difference would be what's connected to the "steps remaining" node, which would be the function that activates one of the four LEDs (if that makes sense). I was thinking that doing it this way would be a little counterintuitive since the only thing that needs to be changed is the LED indicator.

NI Stepper motor

Hi all,
I wan t to have an stepper motor with a built-in encoder. something like ST34-8E from NI. But I'd like to know if it is crucial to drive that buy NI products or I can use any other third party product? I am thinking to use a Gecko power driver and Arduino Uno to drive and control it. It is much cheaper than using NI Compact RIO.
Thanks,
Saridar

Have you seen the new SMD series of stepper motor drives? They are low cost and couple with the integrated stepper motors (ISMs) directly. You wouldn't have to worry about setting up another 3rd party drive with the ISM. They also accept Step/Direction CW/CCW commands you could send from your arduino. Keep in mind, any trajectory generation/ motion profiling will have to be developed by you. One of the benefits of using CompactRIO or our PCI/PXI motion controllers is that you can use the motion software we've already developed in LabVIEW. Let me know if you have any questions!
Regards,
Ian K.
Applications Engineer
National Instruments

Difference between open loop and closed loop mode when finding the index on a stepper motor axis.

I have a test system which uses a PXI-7352 motion controller with a MID-7602 stepper motor drive to position a 200 step/revolution stepper motor with an attached 1000 line encoder. The MID-7602 is configured for 64 microsteps per step, giving 12,800 microsteps and 4000 encoder counts per revolution. The system is controlled using LabView 7.1 and NI-Motion 6.13. To home the motor, I've defined a sequence in MAX which first finds the reverse limit switch and then moves forward to the encoder index pulse.
When finding its reference in open loop mode, the system its reference at the same microstep each time. When findings its reference in closed loop mode, the system finds its reference somewhere within about a 20 microstep wide range.
I hope somebody out there with more experience with this controller can describe the difference between finding the encoder index in open loop mode and finding the encoder index in closed loop mode.
Thanks,
Mark Moss

Hello Mark,
I suspect that the behavior you are experiencing has today
with the resolution difference between your encoder and your
microstepping. Let me illustrate with an
example:
Example Setup
Stepper
Motor
NI
Motion Controller
10
steps per encoder pulse (Every 10 steps the controller gets an encoder
pulse, therefore positions 0-9 all appear to be 0 to the controller)
The
system has a maximum of 3 pull in moves set
Open Loop Scenario
The
system is commanded to go to position 9.
The
controller sends out 9 pulses.
The
motor moves to position 9.
Closed Loop Scenario
The
system is commanded to go to position 9.
The
controller sends out 9 pulses.
The
motor moves to position 9.
The
controller checks its position and sees that it is still at position 0
because it has not received an encoder pulse.
Because
the controller thinks it is still at position 0, it sends another 9 pulses
as its first pull in move.
The
motor moves to position 18.
The
controller checks its position and sees that it is at position 10 because
it has only received one encoder pulse.
Because
the controller thinks it is still at position 10, it sends1 reverse pulse
as its second pull in move.
The
motor moves to position 17.
The
controller checks its position and sees that it is at position 10 because
it has only received one encoder pulse.
Because
the controller thinks it is still at position 10, it sends and additional
single reverse pulse as its third pull in move.
The
motor moves to its final position of 16.
I believe something similar is happening with your
application as it looks for the index pulse.
Because the controller does not compensate for what it perceives as
position error in open loop mode, the motor always goes to the same commanded
position. In closed loop mode, the motor
is bouncing around inside the single index encoder pulse trying to find a
certain position.
There are several recommendations I can make towards
correcting this behavior. These
recommendations are in order of effectiveness:
Setup
your system so that there are more encoder counts per revolution than
steps per revolution.
Turn
off pull-in moves by setting them to 0 in MAX.
Use an
open loop configuration.
Play
around with the pull in window in MAX.
Regards,
Luke H

Trouble positioning a stepper motor accurately (to one step)

I'm using a PCI-7344 with an MD7506 motor driver from RS. I'm testing angle sensors whose voltage output is proportional to (you've guessed it...) angle.
I'm stepping the motor round by one step, checking that it's got there by reading the encoder, measuring the sensor voltage and repeating.
My problem is that the motor sometimes 'hunts' around the target position. In closed loop (with an encoder associated with a motor) this results in sometimes not being able to reach the target exactly with the pull-in moves.
Using open-loop and reading the encoder directly I get better results because I can loop more times, but the motor will still 'hunt' around a target point, changing direction a few times as it over
shoots by a step.
As there are a million MAX settings for this I won't list them all here, but I'm checking for a move complete when the InPos flag is set and I have a deadband of 0 steps too. I'm only rotating at 120 step/sec with a 10ms pause between steps.
Do I have to accept that stepper motors are only accurate to +/- 1 step or am I doing something wrong?
Thanks,
Mike
Mike Evans
TRW Conekt
N.I. Alliance Member, UK
http://www.Conekt.net

Mike,
Maybe other people will have better suggestions, but in my case I can advise to either:
1. increase the number of pull-in moves,
2. increase the microstepping of your drive,
2a... together with a higher precision encoder...
Other than that, the accuracy is advertised to +/- 1 step, so maybe you would like to consider a stepper with more steps/rev.
Good luck!, I hope other people will give other suggestions.
Nestor.
Nestor
National Instruments

Stepper motor and loacell PID control - waveform motion.

Hi,
Hardware : cRio9073, C series module 9403 for stepper motor control and 9215 for load cell data acquisition.
I am trying to control a stepper motor in a closed feedback loop system with a load cell. The user would have to input two things : the maximum load applied and the frequency of the motion. At the moment I have it working in open loop controlling how many steps forwards or backwards it does and at what rate, with a display showing the load being applied.
I am now looking to include the "PID.vi" built into labview into my existing code. I am using the load cell output as the 'process variable' and the 'output' of the PID will control the wait time between an ON and OFF signal to the motor (since I have to do the PWM in software as the 9403 module doesn't do it in hardware. Is this the right way to do it? )
I wish to make the motor do a sinewave motion, thus the 'setpoint' of the PID would be dynamic. I have therefore linked the "Sinewave form.vi" (also built into labview) to the setpoint and the frequency of the "Sinewave form.vi" will be the user input for the frequency of the motor. However my problem lies with the 'Sampling info' of the "Sinewave form.vi" : Previously that is what controlled my number of steps, defining the maximum displacement of the motor. Now I need the peak of the generated sinewave to coincide with the maximum load applied defined by the user. How can I make it do that?
I have attached my existing code with how I have attached the PID.vi at the moment.
Many thanks for your help
Lawrence
Attachments:
PIDControl.vi ‏23 KB
BIOGROWTH.lvproj ‏46 KB

Hi Lawrence,
Here is an example PID VI.
Regards
Rico P
Attachments:
General PID Simulator.vi ‏22 KB

Stepper motor closed loop control using 7344

I have some question about the closed loop control of stepper motor using 7344. From the NI website I got that closed loop steppers work differently from closed loop servos. Instead of adjusting the output on each PID iteration like a servo system, closed loop steppers will do a pull-in move at the end of a move to adjust for any difference between the target position and the encoder feedback. By default, it will attempt the pull-in move three times.
Now for example I got five points: (0,0) (10,20) (30 40) ( 31 60) (50 65). The request time interval I set as 10ms. This mean that in the first 10ms, the machine should move from (0 0) to (10 20). But for some reasons the machine can not move to (10, 20), it moves to (8,16) and the first 10ms passed. In the second 10ms, how it move? Move from (8 16) to (30 40), If like this, the following error will accumulated. In practise, it is not accumulated. Is there anyone can explain something about the closed loop control of stepp motor? Thanks a lot!

Requested Interval is additional data for the Position buffer type. The Position buffer type requires a Requested Interval parameter, and indicates the time between contouring data points in milliseconds. For all other buffer types, the Requested Interval parameter is ignored.
The controller will use the closest value it can that is greater than or equal to the interval value you requested. Your time interval must be an even multiple of the PID rate.
For example, given a PID rate of 250 ms, a time interval of 11.2 ms between points is physically impossible, so a call to configure buffer with an interval of 11.2 causes the buffer to actually be configured for 11.25 ms, since 11.25 is the nearest possible interval greater than 11.2. The following table shows valid intervals for each PID rate.
My question is like this. For example I got five points: (0,0) (10,20) (30 40) ( 31 60) (50 65). The request time interval I set as 10ms. This mean that in the first 10ms, the machine should move from (0 0) to (10 20). If it is impossible for the machine to move from (0 0) to (10 20), there are two ways to solve this problem. First is the time interval is 10ms and assume it move to (8 16) within 10ms and take (8 16) as the start point and (30 40) as the end point of the second move. Second is extend the time interval, assume it takes 14ms to move from (0 0) to (10 20). After 14ms, the (10 20) is the new start point for the second move. I think it works as the second ways.If not, the following error will accumulated. Is there anyone can explain something about the closed loop control of stepp motor in detail? Thanks a lot!

Stepper Motor with Linear Stage (Position Control and Data Acquisition)

Hey All,
So.. I've attached a stepper motor to a linear stage and so far it's working pretty well. Using a stepper motor driver from Pololu, I've simplified the control of the motor by just using output pulses from the counter output of a PXI-6143. I've tested the motor using the Pulse Train examples in LabVIEW and all is working well.
My goal now is to allow the user to collect data from a pressure sensor, attached to the linear stage, every X number of steps. From what I can tell so far, and please correct me if I'm wrong, the motor step movement is synchronised with the pulse train input. That is to say, if I give the motor a 200 step pulse train, the pulse train ouput is completed at the exact time the motor has moved 200 steps. From this, I've created a VI that moves the motor X steps, aquires the data point, and then repeats this process for the required amount of data points. The problem with this is that the motor movement is not continuous; it stops for a split second to take the data point.
How can I have labview ouput a pulse train of say 1000 steps and record a data point every 50 steps?
Two ideas that came to mind were:
1. Use the counter input port on the card to count the pulses being sent to the motor.
2. Use an encoder connected to the motor shaft.
I wanted to stay away from theses ideas though since they require resources from the DAQ card.
Thanks,
Ryan

Hi Ryan,
Just to cover all the bases, what version of LabVIEW are you using and can you attach your VI? Initially your ideas sound like they should work, do you expect to be nearly maxing out the DAQ?
Thank you,
Deborah Y.
LabVIEW Real-Time Product Marketing Manager
Certified LabVIEW Architect
National Instruments

How can I output a square wave to control a stepper motor using 7332 controller?

I have the following system configuration for testing a linear actuator (LA):
LabView 7.1
NI FlexMotion 7332 Motion Controller
NI Flex DMM 4070
The LA is a stepper motor with Step and Direction of Rotation inputs, as well as some discrete I/O for Power Enable and other functions.
The LA specification only requires that I send a 50% Duty Cycle square wave signal with frequency less than 300 Hz to it in order to make it step. The LA has it's own power source. I only need the 7332 to generate the drive signal and the DOR signal to the LA. Using some of the example VI's, I can get the LA to work, but I will need to incorporate the functions in to a custom application.
How can I weed through the numerous advanced functions the 7332 offers and only generate a DOR signal and a step command at a user-defined frequency. How do I set up the controller for this?
Thanks

Hello,
All the VIs that you can use to create a pulse train and digital I/O from your motion controller are found in the "Analog & Digital I/O VIs" sub-palette in the "Flex Motion" palette. Use "Load PWM Duty Cycle" and "Configure PWM Output" VIs to create the square wave. Use the "Set I/O Port Direction", "Set I/O Port MOMO", and "Set I/O Port Polarity" VIs to create digital output. I hope you find this information useful. You can learn about the specifics of these VIs and their inputs/outputs in the NI-Motion VI Help.
Regards,
Aaron B.
National Instruments

How to generate digital pulses to run stepper motor in a sinusoidal motion profile using NI DAQ 6229 card

Hi,
         I need to make a stepper motor undergo rotary oscillation with a sinusoidal motion profile. As it nears the extreme points it should decelerate and finally slow down to zero velocity and then it should reverse direction and accelerate until it reaches the other extremity where it should slow down and stop and reverse direction and repeat this motion.
        The hardware is NI DAQ 6229 and the stepper motor can be controlled using digital Hi-Low (1,0) pulses. For each high pulse(1's) the motor turns 1 step. I am able to generate a analog sine wave and convert it to digital data using Analog-to-Digital.vi But i am not able to convert the digital data to a stream of 1's and 0's in the correct sequence to get the sinusoidal profile with the amplitude and frequency i require.
        The direction of rotation can be changed by giving a pulse to another input of the stepper motor. So only half cycle of sine wave needs to be generated and it can be replayed after changing the direction to get the full sinusoidal profile.
Any ways of making this approach work or any new approaches to this problem would be helpful. Thank You.
Regards,
Prabu.
Solved!
Go to Solution.

Hi,
   I finally figured out a way to do it. The analog sine wave is converted to digital and sampled. Consecutive values are compared and if the least significant bit(LSB) changes then a pulse is sent to the stepper motor to turn one step.
I have included the sub-VI's that accomplish it for the particular stepper motor and connector block i have. The front panel of both sub-VI's are quite messy but the block diagrams should be much clearer. The sub-VI's get their inputs from a third VI which i have not included. So take a look at the VI connector panel to figure it out. Hope this helps. Kinda messy but worked out fine in the end for my application.
Thanks again for all the help. I appreciate it very much.
Regards,
Prabu Sellappan
Graduate Student
Aerospace and Mechanical Enggineering
University of Southern California
Attachments:
start motor test waveform dtest.vi ‏73 KB
sine profile generation subVI.vi ‏41 KB

Error -70006 when using stepper motor in Open Loop Mode

We have a LabView program that runs a test in which a table is rotated. At the end of the test, the table is supposed to rewind. Instead, the following message appears:
Error -7006 occurred at Read Trajectory status.flx
Possible reasons: For FlexMotion, an invalid axis number or other resource ID (Vector Space, Encoder, I/O Port, and so on) was used.
We have the PCI-7344 interfaced with a UMI-7764 and a Zeta4 that is controlling a ZETA83-93 stepper motor. There is no encoder in the system for this motor. The stepper loop mode was originally set to closed loop but the motor behaved erratically (moving multiple times when instructed by MAX to move once). The stepper loop mode was changed to open loop and the m
otor started behaving properly, but that is when the error message starting appearing. Are there any other configuration settings, such as Primary Feedback (which is now set to Encoder) or ? that I may need to correct to resolve this error?

First of all I would check a couple of things. The reason why your motor was not behaving properly in closed loop stepper configuration is most probably related to the fact that you don't have the encoder counts per revolution adn the stepper steps per revolution properly configured for your motor. Please follow the instructions found in the following knowledgebase:
http://digital.ni.com/public.nsf/websearch/29edb56146f274a386256a1c00624310?OpenDocument
When you configure an axis in closed loop stepper mode, we use the information of the encoder to generate the adequate velocity profile. If the encoder counts and steps per revolution are not properly matched, then the motor will not execute the moves properly. What you need to do is the following:
1.-Configure your axis as closed loop stepper in the Axis Conifguration Section in MAX.
2.- In thbe 1-D Interactive Basic panel, kill the motor and click on reset position.
3.- Manually rotate the motor one revolution.
4.- In the advanced panel on 1-D interactive, read the Encoder Value. This is the value you should enter on the Axis Encoder Counts per Revolution under Axis Configuration. Press Apply.
5.- Go back to the 1-D interactive Basic Panel. Change the bullet selector unbder Stepper Loop Mode from Closed to Open. Run a 10000 step move.
6.- When the move is finished, read the encoder counts from the advanced panel. This will tell you how many counts you have in 10000 steps. You can now calculate the stepper steps per revolution by the following formula:
(# of steps per count)*(# counts per revolution) = # steps per revolution.
Your motor should work fine in closed loop stepper configuration now and the error should not appear. Please make sure you are using the latest version of our driver (Ni-Motion 6.0.1)to avoid older firmware errors and fixed bugs from affecting your system. You can get it from:
http://digital.ni.com/softlib.nsf/webcategories/85256410006C055586256BB9002C16DF?opendocument&node=132070_US

What's the type of control for stepper motor?

Hi,
I'm using PXI-7358 controller, UMI-7774, Industrial Device NextStep third part microstepping drive, stepper motor SANYO-DENKI (type 103-8932-6421, NEMA42) and incremental encoder 3600 ppr (14400 count/round). I want to say what's the NI onboard type of control used to control motor step position? In the case of servomotor the type of onboard control is a PID, in the case of stepper motor what's the type of control? What's the MAX parameters to set for the project specific (overshoot, settling time, rise time etc..)? What does it means "Pull-in Window" e "Pull-in Tries" in MAX? So, it's possible control the stepper motor with user's algorithm control, excluding the onboard control?
Thanks for your patience,
Best regards
Lorenzo

>
Matt wrote:
> Go to SE24. Type in cl_dd_document and press enter. Select the methods tab. Look for the method "CONSTRUCTOR". Double click on it. Click on SIGNATURE button. The types of the parameters are clearly seen.
>
> matt
TYPE and VALUES OF TYPE -- different things. For example, TYPE C -- CHAR. VALUES of this: A, B, C, ..., 1, 2, 3.
Thus, return to question.
TYPES: sdydo_attribute(50) TYPE c
TYPE: sdydo_attribute
VALUES: ???
May be, value ABRAKADABRA correct?

Arduino Stepper Motor

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