Sending a motor command to mindstorms NXT using python and the jaraco library.

gistfile1.py

from jaraco.nxt import *
from jaraco.nxt.messages import *

conn = Connection('/dev/tty.NXT-DevB')

cmd = SetOutputState(
                          i,
                          motor_on=True,
                          set_power=motorpower,
                          run_state=RunState.running,
                          use_regulation=True, #this was the crucial part.
                          regulation_mode=RegulationMode.motor_speed
                    )
conn.send(cmds)

# clean up
conn.close()