QPID_MotorDriver_DRV8833 Class Reference

Implement a QPID_MotorDriver for TI's DRV8833 chip based modules. (Watch out for fake modules with the HR8833 chip, they didn't work well for me.) More...

Inheritance diagram for QPID_MotorDriver_DRV8833:

Public Member Functions
void	setPower (int16_t pow)
	Start motor with given power, direction and currently set decay mode. More...
void	coast (void)
	Stop motor in fast decay mode (spinning freely). Does not affect decay mode set by user.
void	brake (void)
	Stop motor in slow decay mode (braking). Does not affect decay mode used in setPower() set by user.
void	setDecay (decayModeType mode)
	Set decay mode (who would have thought that!) More...
void	setFrequency (uint8_t onoff)
	Set PWM frequency. More...
void	enable (void)
	Enable driver chip by pulling nSLEEP pin high. Only use this, if you've specified a pin for nSLEEP.
void	disable (void)
	Disable driver chip by pulling nSLEEP pin low. Only use this, if you've specified a pin for nSLEEP.
void	init (int8_t a, int8_t b, int8_t s, int8_t f)
	Define and initialize pins connected to DRV8833's IN1, IN2, nSLEEP, and nFAULT. More...
int8_t	hasFault (void)
	Report DRV8833 FAULT pin state. More...
Public Member Functions inherited from QPID_Object
virtual void	update ()
	(abstract) Can be overridden by QPID subsystems which need to do their own polling. Will be called by QPID_Unit::update() for subsystems, and by firmware/client for QPID_Unit itself.
void	throwError (const char *invokedBy, const char *errorMessage)
	Writes error message and error invoking class to Serial. More...
void	log (const char *logEntry)
	Puts timestamped string into the system log (atm: writes it out to Serial). More...

Protected Member Functions
bool	processMessage (uint8_t *m) override
	(abstract) Interprets message handed down from QPID_Unit locally. Must be overridden in derived classes
Protected Member Functions inherited from QPID_Object
	QPID_Object ()
	Constructor. Begins Serial with 115200 baud for logging and error reporting, if not done previously.

Additional Inherited Members
Public Types inherited from QPID_MotorDriver
enum	decayModeType : uint8_t { decayModeFast = 0, decayModeSlow = 1 }
	Symbolic names for decay modes that should be used during inactive part of PWM phase, if the driver supports that functionality.
Protected Attributes inherited from QPID_MotorDriver
decayModeType	decayMode = decayModeSlow
int16_t	currentPWM = 0
int16_t	maxPower
int16_t	alwaysOnPWM

Detailed Description

Implement a QPID_MotorDriver for TI's DRV8833 chip based modules. (Watch out for fake modules with the HR8833 chip, they didn't work well for me.)

QPID_MotorDriver)

Supports en/disable by nSLEEP pin and fault signaling by nFAULT pin.

Note

The current implementation is tailored for the ESP32, other platforms would have to be added with preprocessor directives.

Member Function Documentation

setPower()

void QPID_MotorDriver_DRV8833::setPower ( int16_t  pow )

virtual

Start motor with given power, direction and currently set decay mode.

Parameters

pow	PWM value, sign indicates direction.

Note

setPower(0) will also use current decay mode for both pins. Usually brake() or coast() are preferable.

Reimplemented from QPID_MotorDriver.

setDecay()

void QPID_MotorDriver_DRV8833::setDecay ( decayModeType  mode )

virtual

Set decay mode (who would have thought that!)

Usually slow mode will be preferred, cf. https://learn.adafruit.com/improve-brushed-dc-motor-performance/choosing-decay-mode-and-pwm-frequency

Parameters

mode	One of QPID_MotorDriver::decayModeFast or QPID_MotorDriver::decayModeSlow

Reimplemented from QPID_MotorDriver.

setFrequency()

void QPID_MotorDriver_DRV8833::setFrequency ( uint8_t  freq )

virtual

Set PWM frequency.

Usually 50-100 Hz will be ok for Dc motor, cf. https://learn.adafruit.com/improve-brushed-dc-motor-performance/choosing-decay-mode-and-pwm-frequency

Parameters

freq	Frequency in Hz

Reimplemented from QPID_MotorDriver.

init()

void QPID_MotorDriver_DRV8833::init	(	int8_t	a,
		int8_t	b,
		int8_t	s,
		int8_t	f
	)

Define and initialize pins connected to DRV8833's IN1, IN2, nSLEEP, and nFAULT.

Parameters

a	pin IN1
b	pin IN2
s	pin nSLEEP (-1 if not used). Set to LOW (= disabled) initially, i.e. if you specify an nSLEEP pin, you have to call enable() before using the driver.
f	pin nFAULT (-1 if not used). nFAULT is open drain, so the internal pullup is used.

hasFault()

int8_t QPID_MotorDriver_DRV8833::hasFault ( void  )

virtual

Report DRV8833 FAULT pin state.

Returns

true(1) for fault, false(0) for no fault

Reimplemented from QPID_MotorDriver.

---

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

• QPID_MotorDriver_DRV8833.h
• QPID_MotorDriver_DRV8833.cpp