L298 Class Reference

API for the L298 Dual H-Bridge Motor Driver. More...

Detailed Description

• ID: l298
• Name: Dual H-bridge Motor Driver
• Category: motor
• Manufacturer: seeed sparkfun
• Link: https://www.sparkfun.com/products/9670
• Connection: gpio pwm

It was developed using the RobotBase Dual H-Bridge module.

This module can support 2 DC motors, or one 2-phase stepper motor. It requires 3 pins per DC motor (or H-bridge), or 4 pins for the stepper motor (uses both H-bridges).

L298 Dual H-Bridge Motor Driver image provided by SparkFun* under CC BY 2.0.

Example driving a DC motor

    // Instantiate one of the 2 possible DC motors on a L298 Dual
    // H-Bridge.  For controlling a stepper motor, see the l298-stepper
    // example.
    upm::L298 l298(3, 4, 7);

    cout << "Starting motor at 50% for 3 seconds..." << endl;
    l298.setSpeed(50);
    l298.setDirection(upm::L298::DIR_CW);
    l298.enable(true);

    upm_delay(3);

    cout << "Reversing direction..." << endl;
    l298.setDirection(upm::L298::DIR_NONE); // fast stop
    l298.setDirection(upm::L298::DIR_CCW);
    upm_delay(3);

    l298.setSpeed(0);
    l298.enable(false);

Example driving a stepper motor

    // Instantiate a Stepper motor on a L298 Dual H-Bridge.

    // This was tested with the NEMA-17 12V, 350mA, with 200 steps per rev.
    upm::L298 l298(200, 3, 4, 7, 8, 9);

    l298.setSpeed(10); // 10 RPMs
    l298.setDirection(upm::L298::DIR_CW);
    l298.enable(true);
    cout << "Rotating 1 full revolution at 10 RPM speed." << endl;
    // move 200 steps, a full rev
    l298.stepperSteps(200);
    cout << "Sleeping for 2 seconds..." << endl;
    upm_delay(2);
    cout << "Rotating 1/2 revolution in opposite direction at 10 RPM speed." << endl;
    l298.setDirection(upm::L298::DIR_CCW);
    l298.stepperSteps(100);
    // release
    l298.enable(false);

Public Types
enum	L298_DIRECTION_T { DIR_NONE = 0x00, DIR_CW = 0x01, DIR_CCW = 0x02 }

Public Member Functions
	L298 (int pwm, int dir1, int dir2)
	L298 (int stepsPerRev, int en, int i1, int i2, int i3, int i4)
	~L298 ()
uint32_t	getMillis ()
void	initClock ()
void	setPeriodMS (int ms)
void	enable (bool enable)
void	setSpeed (int speed)
void	setDirection (L298_DIRECTION_T dir)
void	stepperSteps (unsigned int steps)

Member Enumeration Documentation

enum L298_DIRECTION_T

Enum to specify the direction of a motor

Constructor & Destructor Documentation

L298	(	int	pwm,
		int	dir1,
		int	dir2
	)

L298 constructor for DC motor(s) connected.

Parameters

pwm	Digital pin to use for a DC motor - must be PWM-capable
dir1	Digital pin to use for motor direction pin 1
dir2	Digital pin to use for motor direction pin 2

L298	(	int	stepsPerRev,
		int	en,
		int	i1,
		int	i2,
		int	i3,
		int	i4
	)

L298 constructor for a 4-wire stepper motor

Parameters

stepsPerRev	Number of steps per full revolution
en	Enables the pin
i1	Digital pin to use for stepper input 1
i2	Digital pin to use for stepper input 2
i3	Digital pin to use for stepper input 3
i4	Digital pin to use for stepper input 4

~L298

(

)

L298 destructor

Member Function Documentation

uint32_t getMillis

(

)

Returns the number of milliseconds elapsed since initClock() was last called.

Returns

Elapsed milliseconds

void initClock

(

)

Resets the clock

void setPeriodMS

(

int

ms

)

Sets the period in milliseconds

Parameters

ms	Period in milliseconds

void enable

(

bool

enable

)

Enables the PWM output for a motor

Parameters

enable

Enables the PWM output if true, disables if false

void setSpeed

(

int

speed

)

Sets the speed of a DC or stepper motor. For a DC motor, values can range from 0 (off) to 100 (full speed). For a stepper motor, specify the desired RPM.

Parameters

speed

Speed to set the motor to

void setDirection

(

L298_DIRECTION_T

dir

)

Sets the direction of the motor, clockwise or counterclockwise

Parameters

dir	Direction to set the motor to

void stepperSteps

(

unsigned int

steps

)

Steps the stepper motor a specified number of steps

Parameters

steps

Number of steps to move the stepper motor

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The documentation for this class was generated from the following files:

• src/l298/l298.hpp
• src/l298/l298.cxx