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Topic: Quadstepper Sparkfun (Read 2423 times) previous topic - next topic

Stickyfinger

Hello,
I want to control 4 Stepper Motor with the Quadstepper (sparkfun) and Arduino duemilanove but I dont know how to connect the parts together. I´m a totaly newbie.
The stepper motor I bought:

STEP ANGLE 1.8° 5% VOLTAGE 12V
PHASES 2 CURRENT 0.33A
INSULATION RESISTANCE 100Mohm(500V DC) INDUCTANCE 46 20% Mh
CLASS OF INSULATION B RESISTANCE 34 10%
WEIGHT 0.20Kg HOLDING TORQUE 0.23N.M

Maybe someone can post a picture.

Thanks Stickyfinger.


Grumpy_Mike

Download the data sheet from:-
http://www.sparkfun.com/products/10507
That is the data sheet for the stepper chip on the board. There are four of those.
Look at page 3 to see how a motor connects up to one chip.
Identify the markings on the board that correspond to those signals, it's not hard.

MarkT

Firstly that's a very expensive way to drive a unipolar motor (given its 12V I'm pretty sure that motor is unipolar and not a 4-wire bipolar - is this true?).  Normally you'd use half a ULN2803 per motor, much cheaper.  However if your supply voltage is more than 12V it will act as a regulator and will improve the performance of the motor - you have to wire the motor as bipolar for the quadstepper.  The quadstepper also reduces the number of pins needed to drive 4 motors and allows you to upgrade the motors later.

The quadstepper is designed for high current bipolar motors driven in PWM mode.  If using for your motors then you _must_ set the current limit using the trimmer pots on the board, ensuring the motor doesn't get more than its rated 0.33A (over current will lead to over-heating, for some motors it may lead to demagnetization and permanent degradation).

For information: bipolar motors for high-speed and high torque operation are usually have windings of a few ohms and take a few amps current.  They are designed to be driven in constant-current mode from controllers like the quadstepper which use PWM.  A high voltage supply allows large back-EMFs to be overcome and thus high rotation speeds (1000's rpm)

Lower performance motors typically have windings of 20 to 200 ohms or so and are often operated from a fixed voltage supply and can be driven by 4 transistors or darlingtons.  They can't approach the maximum speeds of a bipolar motor / PWM driver combination, usually limited to a few 100 rpm.
[ I won't respond to messages, use the forum please ]

Stickyfinger

Thanks for the answers.
At first i´ll try to control one stepper motor.
What I did by now is:
i have connected all 4wires with the quadstepper. (red-green and yellow-blue in my case)
Then solded wires at pins:
CH1:
Microstep Select (MS1, MS2, and MS3),
Direction Input (DIR), Step Input (STP),
and Enable Input (EN).

Step Input (STP) PWM output at the Duemilanove.

Next step i have to do is to write a program to move the motor.

Has someone written something like these before or does someone know a good tutorial or book about that?


@MarkT:
I bought this stepper Motor:
http://physicalcomputing.at/shop/article_A-1107100/Stepper-Motor-Bipolar.html?sessid=9Qlj2jKjcZygLUObgrCMR8Ds0XODxehXwfAcKMJJtnRvq1pEU2SKlQrQ5MKtWvKI&shop_param=cid%3D1%26aid%3DA-1107100%26
.......and thak you very much for the informations.

Grumpy_Mike

Quote
Step Input (STP) PWM output at the Duemilanove.

No you don't feed the step input with PWM, just with pulses every time you want it to step.

Write a simple loop to toggle the output pin connected to the step say 50 times with a 200mS delay between each step just to test that it moves. Then delay for three seconds and repeat.

The micro steps inputs should be left unconnected for the moment.

The Direction input should be wired to an arduino output and held at one level, depending on the direction you want to go, and the enable should be connected to ground.

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