"""run_until_stalled: drive against an obstruction and report where it stopped.

Hold the shaft (or let the mechanism hit its end stop). An unloaded shaft
creeps instead of stalling, so this call does not return until something blocks
it. Ctrl+C aborts and coasts the motor.

duty_limit IS the stall force: the motor pushes up to that percentage of the
voltage cap against the obstruction before the stall is reported, and without a
duty_limit it pushes with the whole pack (an EV3 Large closes a gripper HARD).
50 % is a firm push for an EV3 Medium (its breakaway is about 50 %, so much
below that it cannot move at all and reports the stall at once); an EV3 Large
moves at 40 %.

Needs: one motor on port 1 and something to block its shaft (your hand or an end stop).
"""
from evn import Motor, Stop, wait

m = Motor(1)

print("grab the shaft within the next 3 s ...")
wait(3000)

end = m.run_until_stalled(200, then=Stop.COAST, duty_limit=50)
print("stalled at", end, "deg; stalled() =", m.stalled())

wait(500)
m.reset_angle()                  # the stop becomes the 0 reference
m.run_target(300, -90)           # back off 90 deg from it
print("backed off to", m.angle(), "deg")

m.stop()
m.close()