Class MoveJoystick

ev3dev2.motor.MoveJoystick

Used to control a pair of motors via a single joystick vector.

Declaration

class MoveJoystick(MoveTank)

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Documentation

Methods

▶ def on(self, x, y, radius=100.0) override
Convert ``x``,``y`` joystick coordinates to left/right motor speed percentages and move the motors.
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This method overrides ev3dev2.motor.MoveTank.on.
This will use a classic "arcade drive" algorithm: a full-forward joystick goes straight forward and likewise for full-backward. Pushing the joystick all the way to one side will make it turn on the spot in that direction. Positions in the middle will control how fast the vehicle moves and how sharply it turns.
x, y:
The X and Y coordinates of the joystick's position, with (0,0) representing the center position. X is horizontal and Y is vertical.
radius (default 100):
The radius of the joystick, controlling the range of the input (x, y) values. e.g. if "x" and "y" can be between -1 and 1, radius should be set to "1".

Class methods

▶ def angle_to_speed_percentage(angle) @staticmethod
The following graphic illustrates the **motor power outputs** for the left and right motors based on where the joystick is pointing, of the form ``(left power, right power)``::
@staticmethod
def angle_to_speed_percentage(angle)
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(1, 1)
. . . . . . .
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(0, 1) . | . (1, 0)
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. | . . | x-axis .
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(-1, 1) .---------------------------------------. (1, -1)
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. | y-axis .
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(0, -1) . | . (-1, 0)
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(-1, -1)
The joystick is a circle within a circle where the (x, y) coordinates of the joystick form an angle with the x-axis. Our job is to translate this angle into the percentage of power that should be sent to each motor. For instance if the joystick is moved all the way to the top of the circle we want both motors to move forward with 100% power...that is represented above by (1, 1). If the joystick is moved all the way to the right side of the circle we want to rotate clockwise so we move the left motor forward 100% and the right motor backwards 100%...so (1, -1). If the joystick is at 45 degrees then we move apply (1, 0) to move the left motor forward 100% and the right motor stays still.
The 8 points shown above are pretty easy. For the points in between those 8 we do some math to figure out what the percentages should be. Take 11.25 degrees for example. We look at how the motors transition from 0 degrees to 45 degrees: - the left motor is 1 so that is easy - the right motor moves from -1 to 0
We determine how far we are between 0 and 45 degrees (11.25 is 25% of 45) so we know that the right motor should be 25% of the way from -1 to 0...so -0.75 is the percentage for the right motor at 11.25 degrees.

Inherited methods

Methods inherited from ev3dev2.motor.MoveTank:
__init__, cs, follow_gyro_angle, follow_line, gyro, on_for_degrees, on_for_rotations, on_for_seconds, turn_degrees, turn_left, turn_right
Methods inherited from ev3dev2.motor.MotorSet:
__str__, is_holding, is_overloaded, is_ramping, is_running, is_stalled, off, reset, run_direct, run_forever, run_timed, run_to_abs_pos, run_to_rel_pos, set_args, set_polarity, stop, wait, wait_until, wait_until_not_moving, wait_while

Subclasses

ev3dev2.control.webserver.WebControlledTank

Reexports

Imported in ev3dev2.control.webserver.