These motors are exceptionally affordable and offer remarkable accuracy thanks to their 1/64 gearing. Each step of the motor corresponds to a movement of approximately 0.087890625°. However, it’s important to note that the gearing mechanism is made of plastic, which means that it may experience wear and tear over time, particularly when handling heavy objects. Additionally, if the motors are subjected to intense usage, they may generate heat and become slightly warm.
Circuit
Code
#!/usr/bin/python3
import RPi.GPIO as GPIO
import time
in1 = 17
in2 = 18
in3 = 27
in4 = 22
# careful lowering this, at some point you run into the mechanical limitation of how quick your motor can move
step_sleep = 0.002
step_count = 4096 # 5.625*(1/64) per step, 4096 steps is 360°
direction = False # True for clockwise, False for counter-clockwise
# defining stepper motor sequence (found in documentation http://www.4tronix.co.uk/arduino/Stepper-Motors.php)
step_sequence = [[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]]
# setting up
GPIO.setmode( GPIO.BCM )
GPIO.setup( in1, GPIO.OUT )
GPIO.setup( in2, GPIO.OUT )
GPIO.setup( in3, GPIO.OUT )
GPIO.setup( in4, GPIO.OUT )
# initializing
GPIO.output( in1, GPIO.LOW )
GPIO.output( in2, GPIO.LOW )
GPIO.output( in3, GPIO.LOW )
GPIO.output( in4, GPIO.LOW )
motor_pins = [in1,in2,in3,in4]
motor_step_counter = 0 ;
def cleanup():
GPIO.output( in1, GPIO.LOW )
GPIO.output( in2, GPIO.LOW )
GPIO.output( in3, GPIO.LOW )
GPIO.output( in4, GPIO.LOW )
GPIO.cleanup()
# the meat
try:
i = 0
for i in range(step_count):
for pin in range(0, len(motor_pins)):
GPIO.output( motor_pins[pin], step_sequence[motor_step_counter][pin] )
if direction==True:
motor_step_counter = (motor_step_counter – 1) % 8
elif direction==False:
motor_step_counter = (motor_step_counter + 1) % 8
else: # defensive programming
print( “uh oh… direction should *always* be either True or False” )
cleanup()
exit( 1 )
time.sleep( step_sleep )
except KeyboardInterrupt:
cleanup()
exit( 1 )
cleanup()
exit( 0 )
Stuff you might need for this to run:
sudo apt-get update –fix-missing && sudo apt-get install python3-rpi.gpio
Results
This motor moves at a rate of 5.625*(1/64)° per step, resulting in a total of 2048 steps to complete a 180° rotation.
and 4096 steps for 360°:
