title: Trying to get Azimuth difference in a loop
body: <p>I have a micropython program on a ESP32 connected to a stepper motor via a driver board.
  The software runs in a while true loop. I'm trying to get the azimuth difference between 30 second previous azimuth reading and the post 30 second azimuth reading, then send the difference to the stepper motor. Unfortunately they will not let me post all my code, so here is a small example.....</p>
  <pre><code>import math
  import time
  import Stepper
  from machine import Pin
  s1 = Stepper.create(Pin(26,Pin.OUT),Pin(25,Pin.OUT),Pin(33,Pin.OUT),Pin(32,Pin.OUT), 
  delay=2)
  
  
  while True:
  
  
     xxxxx loop in here I have working code that updates the Azimuth of the sun in 
     realtime every 30 seconds XXXXXXX
  
  
      
      
     s1.angle(azimuth, -1)
  
      
     time.sleep(30)
  </code></pre>