Definitions of API for controlling motors. More...

Enumerations
enum	motor_port_t { EV3_PORT_A = 0, EV3_PORT_B = 1, EV3_PORT_C = 2, EV3_PORT_D = 3, TNUM_MOTOR_PORT = 4 }
	ID for supported motor ports. More...

enum	motor_type_t { NONE_MOTOR = 0, MEDIUM_MOTOR, LARGE_MOTOR, UNREGULATED_MOTOR, TNUM_MOTOR_TYPE }
	Enumeration type for supported motor types. More...

Functions
ER	ev3_motor_config (motor_port_t port, motor_type_t type)
	Configure a motor port. More...

ER_UINT	ev3_motor_get_type (motor_port_t port)
	Get the type of a motor port. More...

int32_t	ev3_motor_get_counts (motor_port_t port)
	Get the angular position of a motor port. More...

ER	ev3_motor_reset_counts (motor_port_t port)
	Reset the angular position of the motor to zero. More...

ER	ev3_motor_set_power (motor_port_t port, int power)
	Set the unregulated power for a motor port. More...

int	ev3_motor_get_power (motor_port_t port)
	Get the actual power of a motor port. More...

ER	ev3_motor_stop (motor_port_t port, bool_t brake)
	Stop a motor port. More...

ER	ev3_motor_rotate (motor_port_t port, int degrees, uint32_t speed_abs, bool_t blocking)
	Rotate a motor port for specified degrees. More...

ER	ev3_motor_steer (motor_port_t left_motor, motor_port_t right_motor, int power, int turn_ratio)
	Move the robot along a curved path using two motors. More...

Detailed Description

Definitions of API for controlling motors.

Enumeration Type Documentation

enum motor_port_t

ID for supported motor ports.

Enumerator
EV3_PORT_A	Port A.
EV3_PORT_B	Port B.
EV3_PORT_C	Port C.
EV3_PORT_D	Port D.
TNUM_MOTOR_PORT	Number of motor ports.

enum motor_type_t

Enumeration type for supported motor types.

Enumerator
NONE_MOTOR	Not connected.
MEDIUM_MOTOR	Medium servo motor.
LARGE_MOTOR	Large servo motor.
UNREGULATED_MOTOR	Unregulated motor.
TNUM_MOTOR_TYPE	Number of motor types.

Function Documentation

ER ev3_motor_config	(	motor_port_t	port,
		motor_type_t	type
	)

Configure a motor port.

Set the type of motor connected to the motor port. You can also specify a new motor type even if you have already set it.

Parameters

port	Motor port to be configured
type	Motor type for the specified motor port

Return values

E_OK	Successful completion
E_ID	Illegal motor port number
E_PAR	Illegal motor type

int32_t ev3_motor_get_counts ( motor_port_t port )

Get the angular position of a motor port.

When an incorrect motor port number is specified, it always returns 0.

Parameters

port	Motor port to be inquired

Returns: Angular position in degrees. A negative value means the motor rotate has rotated backwards. [TODO: number of degrees per one revolution of motor]

int ev3_motor_get_power ( motor_port_t port )

Get the actual power of a motor port.

When an incorrect motor port number is specified, it always returns 0.

Parameters

port	Motor port to be set

Returns: Motor power [TODO: range?]

ER_UINT ev3_motor_get_type ( motor_port_t port )

Get the type of a motor port.

Parameters

port	Motor port to be inquired

Return values

>=0	Motor type of specified motor port
E_ID	Illegal motor port number

ER ev3_motor_reset_counts ( motor_port_t port )

Reset the angular position of the motor to zero.

Setting the value of the angular position sensor of the motor does not affect the actual power and position of the motor.

Parameters

port	Motor port to be inquired

Return values

E_OK	Successful completion
E_ID	Illegal motor port number
E_OBJ	Motor port has not been initialized.

ER ev3_motor_rotate	(	motor_port_t	port,
		int	degrees,
		uint32_t	speed_abs,
		bool_t	blocking
	)

Rotate a motor port for specified degrees.

Parameters

port	Motor port to be rotated
degrees	Degrees to be rotated. A negative value makes the motor rotate backwards.
speed_abs	Speed for rotating. The value is a percentage of full speed, ranging from 0 to +100.
blocking	true (The function will be blocked until the rotation is finished), or false (The function will not be blocked).

Return values

E_OK	Successful completion
E_ID	Illegal motor port number
E_OBJ	Motor port has not been initialized.

ER ev3_motor_set_power	(	motor_port_t	port,
		int	power
	)

Set the unregulated power for a motor port.

Parameters

port	Motor port to be set
power	The percentage of full power, ranging from -100 to +100. A negative value makes the motor rotate backwards.

Return values

E_OK	Successful completion
E_ID	Illegal motor port number
E_OBJ	Motor port has not been initialized.

Start the motor

ER ev3_motor_steer	(	motor_port_t	left_motor,
		motor_port_t	right_motor,
		int	power,
		int	turn_ratio
	)

Move the robot along a curved path using two motors.

Parameters

left_motor	ID of the left motor port
right_motor	ID of the right motor port
power	Power of motors. Range: -100 to +100. A negative value moves the robot backwards.
turn_ratio	The sharpness of the turn. Range: -100 to +100. If turn_ratio is negative, the robot will turn left. If turn_ratio is positive, the robot will turn right. More specifically, turn_ratio determines the ratio of inner wheel speed as a percent. For example, if turn_ratio is +25, the right motor will move at 75% of the power, which makes the robot turn right.

Return values

E_OK	Success
E_ID	Invalid ID of motor port
E_OBJ	Motor port has not been initialized.

ER ev3_motor_stop	(	motor_port_t	port,
		bool_t	brake
	)

Stop a motor port.

Parameters

port	Motor port to be stopped
brake	Brake mode, true for braking, false for coasting.

Return values

E_OK	Successful completion
E_ID	Illegal motor port number
E_OBJ	Motor port has not been initialized.

Enumerations

Functions

Detailed Description

Enumeration Type Documentation

Function Documentation