Hello , this will be my first time using an Arduino and I want to learn to use it while I'm trying to do a basic project . I want to buy a Arduino and use it to control 4 stepper motors all bipolar .
The 4 stepper motors I want to control are SEI-MOT08-008 . They are from a dashboard of a car . From what I've read they are 5v , and the coil resistance (measured with my multimeter) is 132 Ohm . The result Amps needed for the motor to work fine is (by my calculation) 0.032 Amps . If I've calculated correctly is it possible to be able to control the stepper motors alone just with the Arduino or do I still need a driver. If I need a driver which driver would you say is better to reliably driver the motors?
Yes.
It might be ok to use Arduino pins directly, depending what type of Arduino you use. Many of the 5V Arduino (AVR chips) can, theoretically, handle 32mA, but it is 80% of the maximum beyond which damage occurs, so many forum members will advise you against that.
If you do decide to attempt it, there is one very important matter. Flyback diodes. Motor drivers have them built-in, but you will need to add them yourself if using Arduino pins alone.
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Don't even try to run with Arduino without drivers. The driver can make the current go in two directions, just an Arduino can't. There's no sane way to connect an Arduino even if it could handle the 32 mA current. Which it can't! You'd get ugly backfiring spikes from the stepper motor each time you break the current.
I don't know what kind of stepper motor that is, but usually they are not picky about the voltage. My guess is 12 V is just fine. Instead you restrict the current by adjusting a trimpot on the driver.
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It can, it you connect the coil between two pins, like an H-bridge.
5 / 132 = 38mA
Leo..
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It's a "gauge motor", couldn't find datasheet.
https://store.minitools.com/en/dashboard-s-spare-parts/pointer-motors/sei-mot08-008-stepper-motor-chevrolet-holden-opel-rover-seat-skoda-subaru-vauxhall-and-volkswagen-instrument-clusters.html
The SEI-MOT08-008 has 8 pins. Have you figured out the internal connections?
Yes , I even open one up to check and see how it works. The motor does have 8 pins but in reality they are just 4 pins (4 front / 4 back) . The motor have pinouts for rear and front connection but they are the same coils and pins . I measured the resistant oh each coil front and back , and they are within 3 ohm difference . One coil is 132 and the other one is 135 .
Thanks a lot to all of you for help , I will buy an Arduino Uno R3 (ATMEGA328P CH340G)and 4 stepper driver [A4988] and I will reduce the amps of the driver (using a multimeter) to 0.034 ohm and the lowest value possible . I will come back with even more questions when they arrive and I start playing with them . If you have any recommendation for another board/Stepper driver fell free to say I will make the orders in a few days.
I don't see why you want to use a current controlled stepper drivers for that (A4988).
Common H-bridges are normally used for high impedance steppers.
Leo..
Im coming for you help again! I got the Arduino and the drivers all connected and working perfect the stepper motors are doing exactly what I want them do to . The problem that I'm facing right now is this : I want to force the stepper motors to rotate an exact number of steps while installed in the instrument cluster . The stepper motors works perfect outside the cluster but when I install them back in the current flows in to the cluster and not to the stepper motors. Do you have any idea how I could stop this from happening? Im basically trying to make the stepper motors rotate front and back and then resume by disabling the drivers controlled by Arduino and left the controller of the cluster control the stepper motors.
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