Printing controller output

Simply print the output from logitech controller to the screen. This is useful if only to verify that it is working at all.

from fish_hawk import ManualControlNode, pause
from time import time

update_period = 0.05
cntr = ManualControlNode()
try:
    print("starting up communication with logitech controller")
    cntr.isactive(True)
    while True:
        loop_start = time()
        cntr.check_readings()
        print("command out: fb %.2f, lf %.2f ud %.2f turn %.2f"%(
            cntr.vel_forward, cntr.vel_side, cntr.vel_dive, cntr.vel_turn))
        # sleep to maintain constant rate
        pause(loop_start, update_period)
finally:
    print("Shutting down communication with logitech controller")
    cntr.isactive(False)