What kind of code do I need to do PWM on a mini? I just got in some new MINI stepper motors and I can't wait to try them out. Thanks, have a good one!
LOL, that beautiful, that you do?
seeks driver datasheet
No data sheet available :~.... but I have a good amount of them, so if I fry a couple testing their limits then it is not that big of a deal. Also, if anyone else would like one (or several) of these to mess with then just PM me.
i am from Argentina. came to my home?,
got the link from where you bought it?
Steppers and PWM are not usually used together. The stepper steps when a pin goes HIGH and the other three go LOW. What makes you think that PWM is even useful? For what purpose?
What makes you think that PWM is even useful? For what purpose?
It's usefull for microstepping and/or current control
I just got in some new MINI stepper motors and I can't wait to try them out.
Wow those ARE small!
Send me a few and I'll send you two of these:
http://yourduino.com/sunshop2/index.php?l=product_detail&p=172
Code / examples here: http://arduino-info.wikispaces.com/SmallSteppers
PM or email terry@yourduino.com
If Terry is impressed with them then they are even cooler than I thought! 
I am PMing you guys and all the ones that PMed me now for info. I bet some neat projects will come from these!
marcha:
What makes you think that PWM is even useful? For what purpose?
It's usefull for microstepping and/or current control
Hell I am not picky, I will controll 'em with a freakin' Bannana if it will work right! lol! What do YOU sugjest to control these little beasties with?
What do YOU sugjest to control these little beasties with?
How much current do they draw? At what voltage?
Typically, you need a motor driver shield to driver stepper motors, and the Stepper library.
If there was ever a stepper motor small enough to be driven directly from an Arduino I/O pin, I think it would look like those. Any idea what they were designed to do?
Arduino420:
marcha:
What makes you think that PWM is even useful? For what purpose?
It's usefull for microstepping and/or current control
Hell I am not picky, I will controll 'em with a freakin' Bannana if it will work right! lol! What do YOU sugjest to control these little beasties with?
I might try a low current chopping translater/driver like one of these Pololu jobbies: http://www.pololu.com/catalog/product/2131 (I designed and bread-boarded my own chopping translator/driver using an L297/1 translator controlling an L298N driverer using a UC3610N for protection diodes, only to later find the all-in-on Pololu boards at less than the cost of all the parts I used on my breadboard... Grrr...)
I might opt to remove the trim pot on the Paolou and wire on a multi-turn pot (15 or more turns) just for finer grained settings while searching for the killer current. The beauty of feedback based chopping controllers (like these Pololus) is you can feed it more voltage than it is rated for (as long as you don't exceed the breakdown voltage of the coil insulation of course) and the current sensing chops the pulses. The coils acting as inductors end up working much like a switching power supply. That way you get much faster rise-times on the leading edge of the pulse to get more torque. Not sure if you can run it faster because there isn't any additional discharge to shorten the trailing edge of the pulse tho...
I'd power the motor with at least 5VDC and set the current limit as low as I could and slowly ramp it up until I burn the first one out. Figure out what that current setting was, subtract 25% and call that my max current for all the rest. Throw a meter on each coil to figure out the resistance to calculate the ideal non-chopped voltage based on the empirically found current. Throw that as DC onto one coil of a second motor just to verify that the coils won't melt down when the motor is holding position.
I get them from a company in China that "re-claims" electronics from "scrap" that they buy at auctions. The result is cool stuff like this that is hard (or impossible) to find for a good price, BUT, that comes from god knows what, is in limited supply, and has no data sheet. Everyone that has PMed me so far has had at least one extra stepper thrown in free, for experimentation (otherwise known as frying it till the magic White smoke comes out!). I think that it would be cool to see an Arduino Mini creeping along with 2-4 of these under it, or diy clocks, ORRRR!! :D? I have a good amount of them still (that company does not DO small orders) so plenty to go around while they last! PM me. Steve
PaulS:
What do YOU sugjest to control these little beasties with?
How much current do they draw? At what voltage?
Typically, you need a motor driver shield to driver stepper motors, and the Stepper library.
First measure the winding resistance. If its 150 ohms or more each you could consider
directly driving from Arduino pins, so long as 8 schottky diodes were used as flyback diodes
to take over from (and save) the on-chip protection diodes.
I suspect they are autofocus motors or some such from a digital camera.
38 OHMs each, where does that leave me?
Thanks for the steppers, just got 'em today. Haven't had the chance to play with them yet, but hopefully get time over the weekend.
I found this
http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Stepper_Formulas
Have you found any specs for the steppers? Voltage, current draw..?
Just got this information from a fellow I shipped them to.
Hi Stephen,
I received the stepper yesterday and I have done done some preliminary
testing on then. I have a manual step controller. It's nothing but a
bunch or switches that switch in polarities to simulate stepping. I
started using 5 v and then pushed it up to 7 v. With continuous
current on the coils the stepper started to heat up noticably. I found
at this voltage the current was 153 ma @ 7v. The steppers have an 8
step per revolution. I think this can be refined using half steps and
a dedicated controller chip. I'll be looking into that. Soldering a
lead to the post is something that you have to be quick and use a very
small iron. The plastic case for the post will melt in a heart beat! I
do not have anything definite on the torgue yet as the controller chip
when I find it and get it hooked up will answer this more directly. So
far the steppers seem well made and work consistently with the
primitive setup that I used to make the steps.
Again the controller chip is what I need to look into next. I will
keep you informed. I would be interested in ordering more in the near
future after I get a controller chip connected.
Just got motor driver chips SO SMALL that I have no clue how to even solder them, any clues?
Thanks!
UPDATE!!! XD
Waltr, over at the Society Of Robots forum has received his steppers and has done ALL of the research to figure out the specs on these Mini Steppers and it is posted here;
Now that all the head scratching is out of the way, we can get to the fun stuff!
@TerryKing; have you had a chance to mess with your steppers any?