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Topic: Controlling Nema 17 stepper with pololu A4988 (Read 1 time) previous topic - next topic

Chrichri_Machine

Aug 19, 2015, 10:34 pm Last Edit: Aug 19, 2015, 10:41 pm by Chrichri_Machine
Hi , :)
 
I have two steppers I need to test using  A4988 Stepper Motor Drivers and Arduino.

STEPPERS SPECS

Nema 17 stepper motor :

200 steps per revolution (1.8 deg/step)
2 Phase bipolar 4 wires
Rated Voltage 2V DC
Rated Current 1.2A

Nema 17 stepper motor:

200 steps per revolution (1.8 deg/step)
2 Phase 4 wires
Rated Voltage 4.83V
Rated Current 0.84A

I have connected the motors countless times according to the diagram in the link below


My circuit is powered by a 9V battery, the direction and step pins are connected to pin 8 and 9 respectively, on the Arduino. I am using a UNO board and I am quite sure that the wiring is correct unless something really important isn't mentioned on the diagram. But no matter what demo code I run, the motor just vibrates and makes a scary noise but the shaft doesn't rotate  :( . I really can not identify my problem, need help  :smiley-confuse:

jremington

The small, rectangular 9V batteries are totally unsuitable for either the Arduino or motors.

Motors and the Arduino should always be  powered separately. You will also need a substantial power supply or a reasonably good sized battery supply to run motors. A 6-cell NiMH RC hobby pack would work for a while.

Carefully follow the instructions on the Pololu A4988 product page for wiring AND for setting the current limit.

Chrichri_Machine

the 9V battery only powers the motor through VMOT and GND on the driver and the arduino is powered via usb by the computer I think. As I said I am just in the testing phase of my project and this set up isn't permanent. Thanks for the battery suggestion though. I got the motors to rotate with a sample code  by reducing the delay a bit but it still makes an annoying sound. I'll try with a better PSU and see what's up. Thank you...

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