import RPi.GPIO as GPIO
from time import sleep

servoPin = 17

GPIO.setmode(GPIO.BCM) #use Broadcom numbering scheme
GPIO.setup(servoPin, GPIO.OUT) #set servoPin as an output


p = GPIO.PWM(servoPin, 50) #create PWM object called p with freq of 50 Hz
p.start(2.0) #start PWM with duty cycle of 50%

def servoTest(speed): #define a function called servoTest that takes in one arg called speed
    p.ChangeDutyCycle(2.0) #make the duty cycle 2: move servo counterclockwise
    sleep(speed) #wait
    p.ChangeDutyCycle(12.0) #make the duty cycle 12: move servo clockwise
    sleep(speed) #wait
    print("Done") ## When loop is complete, print "Done"
    GPIO.cleanup() #stop GPIO


servoTest(2.0) #run the servoTest function using a speed of 2.0 seconds between movements