Linus Atorf’s MotorControl Support

class nxt.motcont.MotCont(brick)

Interface to MotorControl.

This class provides an interface to Linus Atorf’s MotorControl NXC program. It is a wrapper which follows the MotorControl documentation and provides command strings and timing intervals as dictated there.

To use this module, you will need to put MotorControl22.rxe on your NXT brick. It can be built using NXC and the corresponding source can be found at https://github.com/schodet/MotorControl.

Use MotCont.start() to start the program. You can also start it manually my using the menu on the brick. When your script exits, it would be a good idea to do MotCont.stop().

Original MotorControl site is no longer available, but you can still find a mirror on web archive.

Parameters:: brick (Brick) –

cmd(ports, power, tacholimit, speedreg=True, smoothstart=False, brake=False)

Send a controlled motor command to MotorControl.

Parameters:

ports (Union[Port, Iterable[Port]]) – Port or ports to control, use one of the port identifiers, or an iterable returning one or two of them.
power (int) – Speed or power, -100 to 100.
tacholimit (int) – Position to drive to, 1 to 999999.
speedreg (bool) – True to enable regulation.
smoothstart (bool) – True to enable smooth start.
brake (bool) – True to hold brake at end of movement.

Return type:

None

The motors on the selected ports must be idle, i.e. they can not be carrying out any other movement commands. If this should happen, the NXT will indicate this error by a signal (high and low beep) and will drop the message. To find out if a motor is ready to accept new commands, use the is_ready() method. It is also possible to stop the motor before using set_output_state() method.

In certain situations, set_output_state() method should be used instead. See set_output_state() for more details.

reset_tacho(ports)

Reset NXT tacho count.

Parameters:: ports (Union[Port, Iterable[Port]]) – Port or ports to control, use one of the port identifiers, or an iterable returning one to three of them.
Return type:: None

is_ready(port)

Determine the state of a single motor.

Parameters:: port (Union[Port, Iterable[Port]]) – Port to control, use one of the port identifiers, or an iterable returning one of them.
Returns:: True if the motor is ready to accept new commands.
Return type:: bool

set_output_state(ports, power, tacholimit, speedreg=True)

Send a classic motor command to MotorControl.

Parameters:

ports (Union[Port, Iterable[Port]]) – Port or ports to control, use one of the port identifiers, or an iterable returning one or two of them.
power (int) – Speed or power, -100 to 100.
tacholimit (int) – Position to drive to, 1 to 999999, or 0 for unlimited.
speedreg (bool) – True to enable regulation.

Return type:

None

This is similar to the regular nxt.brick.Brick.set_output_state() method, but informs the MotorControl program to avoid any unwanted side effect.

When to use set_output_state() instead of cmd():

when tacholimit is 0 for unlimited movement,
or when the motor must coast (spin freely) after tacholimit has been reached (it will overshoot then),
or when you want to be able to change the power of a running motor at runtime.

Also use this method to stop a currently running motor:

To stop and let a motor spin freely (coasting), use power 0 and no regulation.
To stop and hold the current position (brake), use power 0 with regulation.

start(version=22)

Start the MotorControl program on the brick.

Parameters:: version (int) – Version to start, default to 22 (version 2.2).
Return type:: None

It needs to already be present on the brick’s flash and named MotorControlXX.rxe, where XX is the version number passed as the version argument.

Warning

When starting or stopping a program, the NXT firmware resets every sensors and motors.

stop()

Stop the MotorControl program.

All this actually does is to stop the currently running program.

Warning

When starting or stopping a program, the NXT firmware resets every sensors and motors.

Return type:: None