#CURRENT APPLICATION INFO
#200 steps/rev
#12V, 350mA
#Big Easy driver = 1/16 microstep mode
#Turn a 200 step motor left one full revolution: 3200

from time import sleep
import RPi.GPIO as gpio #https://pypi.python.org/pypi/RPi.GPIO
#import exitHandler #uncomment this and line 58 if using exitHandler

class Stepper:
	#instantiate stepper 
	#pins = [stepPin, directionPin, enablePin]
	def __init__(self, pins):
		#setup pins
		self.pins = pins
		self.stepPin = self.pins[0]
		self.directionPin = self.pins[1]
		self.enablePin = self.pins[2]
		
		#use the broadcom layout for the gpio
		gpio.setmode(gpio.BCM)
		
		#set gpio pins
		gpio.setup(self.stepPin, gpio.OUT)
		gpio.setup(self.directionPin, gpio.OUT)
		gpio.setup(self.enablePin, gpio.OUT)
		
		#set enable to high (i.e. power is NOT going to the motor)
		gpio.output(self.enablePin, True)
		
		print("Stepper initialized (step=" + self.stepPin + ", direction=" + self.directionPin + ", enable=" + self.enablePin + ")")
	
	#clears GPIO settings
	def cleanGPIO(self):
		gpio.cleanup()
	
	#step the motor
	# steps = number of steps to take
	# dir = direction stepper will move
	# speed = defines the denominator in the waitTime equation: waitTime = 0.000001/speed. As "speed" is increased, the waitTime between steps is lowered
	# stayOn = defines whether or not stepper should stay "on" or not. If stepper will need to receive a new step command immediately, this should be set to "True." Otherwise, it should remain at "False."
	def step(self, steps, dir, speed=1, stayOn=False):
		#set enable to low (i.e. power IS going to the motor)
		gpio.output(self.enablePin, False)
		
		#set the output to true for left and false for right
		turnLeft = True
		if (dir == 'right'):
			turnLeft = False;
		elif (dir != 'left'):
			print("STEPPER ERROR: no direction supplied")
			return False
		gpio.output(self.directionPin, turnLeft)

		stepCounter = 0
	
		waitTime = 0.000001/speed #waitTime controls speed

		while stepCounter < steps:
			#gracefully exit if ctr-c is pressed
			#exitHandler.exitPoint(True) #exitHandler.exitPoint(True, cleanGPIO)

			#turning the gpio on and off tells the easy driver to take one step
			gpio.output(self.stepPin, True)
			gpio.output(self.stepPin, False)
			stepCounter += 1
 
			#wait before taking the next step thus controlling rotation speed
			sleep(waitTime)
		
		if (stayOn == False):
			#set enable to high (i.e. power is NOT going to the motor)
			gpio.output(self.enablePin, True)

		print("stepperDriver complete (turned " + dir + " " + str(steps) + " steps)")