adding some comments

Freenove_Ultimate_Starter_Kit_for_Raspberry_Pi/Code/Python_Code/13.1.1_Motor/Motor.py

@@ -9,7 +9,7 @@ import RPi.GPIO as GPIO
 import time
 from ADCDevice import *
 
-# define the pins connected to L293D 
+# define the pins connected to L293D
 motoRPin1 = 13
 motoRPin2 = 11
 enablePin = 15
@@ -27,18 +27,18 @@ def setup():
         "Program Exit. \n");
         exit(-1)
     global p
-    GPIO.setmode(GPIO.BOARD)   
+    GPIO.setmode(GPIO.BOARD)
     GPIO.setup(motoRPin1,GPIO.OUT)   # set pins to OUTPUT mode
     GPIO.setup(motoRPin2,GPIO.OUT)
     GPIO.setup(enablePin,GPIO.OUT)
-        
+
     p = GPIO.PWM(enablePin,1000) # creat PWM and set Frequence to 1KHz
     p.start(0)
 
 # mapNUM function: map the value from a range of mapping to another range.
 def mapNUM(value,fromLow,fromHigh,toLow,toHigh):
     return (toHigh-toLow)*(value-fromLow) / (fromHigh-fromLow) + toLow
-	
+
 # motor function: determine the direction and speed of the motor according to the input ADC value input
 def motor(ADC):
     value = ADC -128
@@ -54,6 +54,7 @@ def motor(ADC):
         GPIO.output(motoRPin1,GPIO.LOW)
         GPIO.output(motoRPin2,GPIO.LOW)
         print ('Motor Stop...')
+    # the more you turn the potentiometer either direction, the faster the motor speed.
     p.start(mapNUM(abs(value),0,128,0,100))
     print ('The PWM duty cycle is %d%%\n'%(abs(value)*100/127))   # print PMW duty cycle.
 
@@ -67,7 +68,7 @@ def loop():
 def destroy():
     p.stop()  # stop PWM
     GPIO.cleanup()
-    
+
 if __name__ == '__main__':  # Program entrance
     print ('Program is starting ... ')
     setup()