Raspberry Pi 28-BYJ-48 stepper motor control with uln2003

Question

I am currently trying to control the 28-BYJ-48 step motor with a uln2003 driver. When I run my code, the motor buzzes and does not move. In the code attached, I am using pygame to recieve input from a controller, and ultimately turn the motor. I was able to turn the motor with a demo code, but with the new code the motor just buzzes, and changes pitch when the direction is changed. (receiving the input is not the problem, I have tested it multiple times)

Attached below is the code:

control_pins = [7, 8, 11, 9]
for pin in control_pins:
        GPIO.setup(pin, GPIO.OUT)
        GPIO.output(pin, 0)

halfstep_cw = [
        [1,0,0,0],
        [1,1,0,0],
        [0,1,0,0],
        [0,1,1,0],
        [0,0,1,0],
        [0,0,1,1],
        [0,0,0,1],
        [1,0,0,1]
]

halfstep_ccw = [
        [1,0,0,1],
        [0,0,0,1],
        [0,0,1,1],
        [0,0,1,0],
        [0,1,1,0],
        [0,1,0,0],
        [1,1,0,0],
        [1,0,0,0]
]

control = controller()
#Note, that to use the driver and the controller at all times,
#They must be in a loop
quit = False
while quit == False:
        for event in pygame.event.get():
                if (event.type == pygame.QUIT):
                        quit = True
#This is getting axis 1 to move forward and backward
        move_FB = control.get_value(1)
#This is getting axis 2 to move left and right
        move_LR = control.get_value(2)
#This is getting the value of the buttons, with axis i
        circle = control.get_button_value(13)
        R1 = control.get_button_value(11)
        L1 = control.get_button_value(10)
#For buttons, 1 is pressed, 0 is not pressed
#This will quit the program
        elif circle == 1:
                quit = True
#Move the stepper motor clockwise
        elif R1 == 1:
                 for halfstep in range(8):
                        for pin in range(4):
                                GPIO.output(control_pins[pin], halfstep_cw[halfstep][pin])
#Move the stepper motor counter-clockwise
        elif L1 == 1:
                 for halfstep in range(8):
                        for pin in range(4):
                                GPIO.output(control_pins[pin], halfstep_ccw[halfstep][pin])
        else:
                stop()
GPIO.cleanup()
pygame.QUIT

Any help will be much appreciated.

Answer 1

I use this code:

import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
coil_A_1_pin = 17 # IN1
coil_A_2_pin = 18 # IN2
coil_B_1_pin = 21 # IN3
coil_B_2_pin = 22 # IN4

# adjust if different
StepCount=8
Seq = [[1,0,0,1],
       [1,0,0,0],
       [1,1,0,0],
       [0,1,0,0],
       [0,1,1,0],
       [0,0,1,0],
       [0,0,1,1],
       [0,0,0,1]]

GPIO.setup(coil_A_1_pin, GPIO.OUT)
GPIO.setup(coil_A_2_pin, GPIO.OUT)
GPIO.setup(coil_B_1_pin, GPIO.OUT)
GPIO.setup(coil_B_2_pin, GPIO.OUT)

def setStep(w1, w2, w3, w4):
    GPIO.output(coil_A_1_pin, w1)
    GPIO.output(coil_A_2_pin, w2)
    GPIO.output(coil_B_1_pin, w3)
    GPIO.output(coil_B_2_pin, w4)

def forward(delay, steps):
    for i in range(steps):
        for j in range(StepCount):
            setStep(Seq[j][0], Seq[j][1], Seq[j][2], Seq[j][3])
            time.sleep(delay)

def backwards(delay, steps):
    for i in range(steps):
        for j in reversed(range(StepCount)):
            setStep(Seq[j][0], Seq[j][1], Seq[j][2], Seq[j][3])
            time.sleep(delay)

if name == '__main__':
    while True:
        delay = input("Time Delay (ms)?")
        steps = input("How many steps forward? ")
        forward(int(delay) / 1000.0, int(steps))
        steps = input("How many steps backwards? ")
        backwards(int(delay) / 1000.0, int(steps))

Answer 2

Answered my own question. just added in a time.sleep function, as shown below.

        elif R1 == 1:
                 for halfstep in range(8):
                        for pin in range(4):
                                GPIO.output(control_pins[pin], halfstep_cw[halfstep][pin])
                        time.sleep(0.001)
#Move the stepper motor counter-clockwise
        elif L1 == 1:
                 for halfstep in range(8):
                        for pin in range(4):
                                GPIO.output(control_pins[pin], halfstep_ccw[halfstep][pin])
                        time.sleep(0.001)