In order to build a sampler, I use a stepper motor to move a tray along a linear rail. I’m using a NEMA 17 size motor with a step angle of 1.8° and a peak current of 1.68A/phase.
The stepper motor and the driver are mounted as follows:
I also set the current limit to 1.0 using the formula: Current Limit = VREF x 2 x 70% (for full step mode)
Finally, my motor connection is as follows: (after checking the pairs with a multimeter)
B2 : blue ; B1: red ; A1: green ; A2: black.
My problem :
→ all the connections seem ok but my stepper motor makes an abnormal strident noise as soon as I feed it…
→ when the power is on, its impossible to turn the motor by hand
→ during my first tests with the stepper motor( 1 week ago), he responded well to the code (despite the shrill noise). But today he doesnt answer at all. I think the condition of the motor is getting worse as I test it.
`
#import Arduino library
from bbio import *
#Define pins
stepPin = GPIO2_3
dirPin = GPIO2_4
#Set the pins as output
def setup():
pinMode(stepPin, OUTPUT)
pinMode(dirPin, OUTPUT)
def loop():
digitalWrite(dirPin, HIGH)
for i in xrange(0,200,2):
digitalWrite(stepPin, HIGH)
delayMicroseconds(500)
digitalWrite(stepPin, LOW)
delayMicroseconds(500)
delay(1000)
run(setup, loop)
`
Has anyone ever used this driver to control the stepper motor? I said that I already tried to control it with an EasyDriver but my stepper motor needs a minimum current of 1 to 1.2A to activate the coils (easydriver: max 0.75A continuously or otherwise 0.85A).