GroveMD Class Reference

C++ API for the Grove I2C Motor Driver. More...

Detailed Description

• ID: grovemd
• Name: Grove I2C Motor Driver
• Category: motor
• Manufacturer: seeed
• Connection: i2c

This class implements support for the Grove I2C Motor Driver. This device can support a single 4-wire stepper motor, OR two 2-wire DC motors. The device contains an Atmel ATmega8L microcontroller that manages an L298N H-bridge driver chip.

This device supports an i2c bus speed of 100Khz only.

The module does not provide any telemetry or status – it only accepts I2C commands for its various operations.

This module was tested with version 1.3 of the Grove I2C Motor Driver

  // Instantiate an I2C Grove Motor Driver on I2C bus 0

  upm::GroveMD *motors = new upm::GroveMD(GROVEMD_I2C_BUS, 
                                          GROVEMD_DEFAULT_I2C_ADDR);

  // set direction to CW and set speed to 50%
  cout << "Spin M1 and M2 at half speed for 3 seconds" << endl;
  motors->setMotorDirections(upm::GroveMD::DIR_CW, upm::GroveMD::DIR_CW);
  motors->setMotorSpeeds(127, 127);
  
  sleep(3);
  // counter clockwise
  cout << "Reversing M1 and M2 for 3 seconds" << endl;
  motors->setMotorDirections(upm::GroveMD::DIR_CCW, upm::GroveMD::DIR_CCW);
  sleep(3);

Public Types
enum	REG_T {   SET_SPEED = 0x82, SET_PWM_FREQ = 0x84, SET_DIRECTION = 0xaa, SET_MOTOR_A = 0xa1,   SET_MOTOR_B = 0xa5, STEPPER_ENABLE = 0x1a, STEPPER_DISABLE = 0x1b, STEPPER_NUM_STEPS = 0x1c }
enum	STEP_DIRECTION_T { STEP_DIR_CCW = 0x0a, STEP_DIR_CW = 0x05 }
enum	DC_DIRECTION_T { DIR_CCW = 0x02, DIR_CW = 0x01 }

Public Member Functions
	GroveMD (int bus=GROVEMD_I2C_BUS, uint8_t address=GROVEMD_DEFAULT_I2C_ADDR)
	~GroveMD ()
bool	writePacket (REG_T reg, uint8_t data1, uint8_t data2)
bool	setMotorSpeeds (uint8_t speedA, uint8_t speedB)
bool	setPWMFrequencyPrescale (uint8_t freq=0x03)
bool	setMotorDirections (DC_DIRECTION_T dirA, DC_DIRECTION_T dirB)
bool	enableStepper (STEP_DIRECTION_T dir, uint8_t speed)
bool	disableStepper ()
bool	setStepperSteps (uint8_t steps)

Constructor & Destructor Documentation

GroveMD	(	int	bus = GROVEMD_I2C_BUS,
		uint8_t	address = GROVEMD_DEFAULT_I2C_ADDR
	)

grovemd constructor

Parameters

bus	i2c bus to use
address	i2c address to use

~GroveMD

(

)

GroveMD Destructor

Member Function Documentation

bool writePacket	(	REG_T	reg,
		uint8_t	data1,
		uint8_t	data2
	)

Compose and write a 3-byte packet to the controller

Parameters

reg	register location
data1	first byte of data
data2	second byte of data

Returns

true if write successful

bool setMotorSpeeds	(	uint8_t	speedA,
		uint8_t	speedB
	)

For controlling DC motors, set the speeds of motors A & B. Valid values are 0-255.

Parameters

speedA	speed of motor A
speedB	speed of motor B

Returns

true if command successful

bool setPWMFrequencyPrescale

(

uint8_t

freq = 0x03

)

For controlling DC motors, set the PWM frequency prescale factor. Note this register is not ducumented other than to say that the default value is 0x03. Presumably this is the timer pre-scale factor used on the ATMega MCU timer driving the PWM.

Parameters

freq	PWM prescale frequency, default 0x03

Returns

true if command successful

bool setMotorDirections	(	DC_DIRECTION_T	dirA,
		DC_DIRECTION_T	dirB
	)

For controlling DC motors, set the directions of motors A & B

Parameters

dirA	direction for motor A, DIR_CW or DIR_CCW
dirB	direction for motor B, DIR_CW or DIR_CCW

Returns

true if command successful

bool enableStepper	(	STEP_DIRECTION_T	dir,
		uint8_t	speed
	)

For controlling a stepper motor, set a direction, speed and then enable.

Parameters

dir	direction, STEP_DIR_CW or STEP_DIR_CCW
speed	motor speed. Valid range is 1-255, higher is slower.

Returns

true if command successful

bool disableStepper

(

)

For controlling a stepper motor, stop the stepper motor.

Returns

true if command successful

bool setStepperSteps

(

uint8_t

steps

)

For controlling a stepper motor, specify the number of steps to execute. Valid values are 1-255, 255 means to rotate continuously.

Parameters

steps

number of steps to execute. 255 means rotate continously.

Returns

true if command successful

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

• /var/lib/jenkins/workspace/upm-doc-stable/src/grovemd/grovemd.h
• /var/lib/jenkins/workspace/upm-doc-stable/src/grovemd/grovemd.cxx