message: Begin restoring PID controller class
diff: import socket
  import numpy as np
  +from pidcontroller import AltitudePidController
  # Comms
  HOST = '127.0.0.1'
  @@ -36,6 +37,8 @@ if __name__ == '__main__':
  telemSocket.bind((HOST, TELEM_PORT))
  lastError = 0
  + integralError = 0
  + windupMax = 10
  while True:
  @@ -56,14 +59,14 @@ if __name__ == '__main__':
  # Compute dzdt setpoint and error
  velTarget = (ALTITUDE_TARGET- z) * ALT_P
  velError = velTarget - dzdt
  + integralError = AltitudePidController._constrainAbs(integralError + velError * dt, windupMax)
  # Update error integral and error derivative
  deltaError = (velError - lastError) / dt if abs(lastError) > 0 else 0
  -
  lastError = velError
  # Compute control u
  - u = VEL_P * velError + VEL_D * deltaError
  + u = VEL_P * velError + VEL_D * deltaError + VEL_I * integralError
  print('%+3.3f' % u)
  