GroveMD Class Reference

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

Detailed Description

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

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.

For stepper operation, this driver can run in one of two modes - Mode 1, where this driver handles the stepping operation, and Mode 2, where this driver simply sends commands to the Grove Motor Driver, and it handles the stepping operation. Mode2 requires updated (and working) firmware to be loaded onto the device.

The default stepper operation mode is Mode1, which is generally more flexible and is supported on all firmware revisions.

An example showing the use of a DC motor

An example showing the use of a 4-wire stepper

Classes
class	DC_DIRECTION_T
class	REG_T
class	STEP_DIRECTION_T
class	STEP_MODE_T

Public Member Functions
synchronized void	delete ()
	GroveMD (int bus, short address)
	GroveMD (int bus)
boolean	writePacket (GroveMD.REG_T reg, short data1, short data2)
boolean	setMotorSpeeds (short speedA, short speedB)
boolean	setPWMFrequencyPrescale (short freq)
boolean	setPWMFrequencyPrescale ()
boolean	setMotorDirections (GroveMD.DC_DIRECTION_T dirA, GroveMD.DC_DIRECTION_T dirB)
boolean	enableStepper (GroveMD.STEP_DIRECTION_T dir, short speed)
boolean	disableStepper ()
boolean	setStepperSteps (long steps)
void	configStepper (long stepsPerRev, GroveMD.STEP_MODE_T mode)
void	configStepper (long stepsPerRev)

Constructor & Destructor Documentation

GroveMD	(	int	bus,
		short	address
	)

GroveMD constructor

Parameters

bus	I2C bus to use
address	I2C address to use

Member Function Documentation

void configStepper	(	long	stepsPerRev,
		GroveMD.STEP_MODE_T	mode
	)

Configure the initial Stepper parameters. This should be called before any other stepper method.

Parameters

stepsPerRev	The number of steps required to complete one full revolution.
mode	The stepper operating mode, default STEP_MODE1

Returns

Elapsed milliseconds

boolean disableStepper

(

)

To control a stepper motor, stops the stepper motor.

Returns

True if successful

boolean enableStepper	(	GroveMD.STEP_DIRECTION_T	dir,
		short	speed
	)

To control a stepper motor, sets its direction and speed, and then starts operation. For Mode2, this method will return immediately. For Mode1 (the default) this method returns when the number of steps specified by setStepperSteps() has completed.

Parameters

dir	Direction, STEP_DIR_CW or STEP_DIR_CCW
speed	Motor speed. Valid range is 1-255. For Mode 1 (default), this specifies the speed in RPM's. For Mode 2, speed is multiplied by 4ms by the board, so higher numbers will mean a slower speed.

Returns

True if successful

boolean setMotorDirections	(	GroveMD.DC_DIRECTION_T	dirA,
		GroveMD.DC_DIRECTION_T	dirB
	)

To control DC motors, sets 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 successful

boolean setMotorSpeeds	(	short	speedA,
		short	speedB
	)

To control DC motors, sets the speed of motors A & B. Valid values are 0-255.

Parameters

speedA	Speed of motor A
speedB	Speed of motor B

Returns

True if successful

boolean setPWMFrequencyPrescale

(

short

freq

)

To control DC motors, sets the PWM frequency prescale factor. Note: this register is not ducumented other than to say the default value is 0x03. Presumably, this is the timer prescale factor used on the ATMega MCU timer driving the PWM.

Parameters

freq	PWM prescale frequency; default is 0x03

Returns

True if successful

boolean setStepperSteps

(

long

steps

)

To control a stepper motor, specifies the number of steps to execute. For Mode2, valid values are between 1-255, 255 means continuous rotation.

For Mode1 (the default) steps can be any positive integer.

Parameters

steps

Number of steps to execute. 255 (only in Mode2) means continuous rotation.

Returns

True if successful

boolean writePacket	(	GroveMD.REG_T	reg,
		short	data1,
		short	data2
	)

Composes and writes a 3-byte packet to the controller

Parameters

reg	Register location
data1	First byte of data
data2	Second byte of data

Returns

True if successful

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

• /var/lib/jenkins/workspace/upm-doc-stable/build-33/src/grovemd/GroveMD.java