Motor_control.py

from math import sqrt
from Bipolar_Stepper_Motor_Class import Bipolar_Stepper_Motor
from time import sleep
from threading import Thread

#Anti-backlash direction logging - the motor at home position last went in the -1 direction toward home
stepper1_last_direction=-1
stepper2_last_direction=-1

def sign(a): #translate integer signed value into integer direction
    if a>0: #positive movement, 1
        return 1
    elif a<0:#negative movement, -1
        return -1
    elif a==0:
        return 0
    else:
        print "Motor control function sign got a bad step value!"

def Motor_Step(stepper1, step1, stepper2, step2, speed):
    global stepper2_last_direction,stepper1_last_direction
    dir1=sign(step1) #make signed step integer into which direction
    dir2=sign(step2)
    if abs(dir1-stepper1_last_direction)==2: #If this is true, the motor has gone from one direction to the opposite, not just to 0
        stepper1.correctBacklash(dir1) #correct for backlash
        stepper1_last_direction=dir1 # set last direction moved in to the direction the motor will now be moving in
    if abs(dir2-stepper2_last_direction)==2:
        stepper2.correctBacklash(dir2)
        stepper2_last_direction=dir2
    step1=abs(step1) #turn step value into # of steps
    step2=abs(step2)
    duration=sqrt(step1**2+step2**2)/speed #Pythagorean theorem to figure out total distance moved
    stepper1_thread=Thread(target=stepper1.move,args=(step1,dir1,duration,))#set up a thread for one motor
    stepper2_thread=Thread(target=stepper2.move,args=(step2,dir2,duration,))
    stepper1_thread.daemon=True #if the program shuts down, these threads will, too
    stepper2_thread.daemon=True
    stepper1_thread.start()#starts both threads at the same time - the motors move together
    stepper2_thread.start()
    sleep(duration)
    while stepper1_thread.isAlive()==True or stepper2_thread.isAlive()==True: #ascertain that the motors are done before moving on
        sleep(0.0001)