Agragate of 16 PWM channels for a PCA9685PWM. More...

#include <PCA9685PWM.hxx>

Inheritance diagram for PCA9685PWM:

Classes
struct	LedCtl
	Representation of the replicative 4 LED control register. More...

union	Mode1
	Represent the mode 1 register. More...

union	Mode2
	Represent the mode 2 register. More...

Public Member Functions
	PCA9685PWM ()
	Constructor.

void	init (const char *name, uint8_t i2c_address, uint16_t pwm_freq=200, int32_t external_clock_freq=-1)
	Initialize device.

	~PCA9685PWM ()
	Destructor.

Public Member Functions inherited from OSThread
	OSThread (const char name, int priority, size_t stack_size, void (start_routine)(void ), void *arg)
	Create a thread.

	OSThread ()
	Creates a thread via inheritance.

void	start (const char *name, int priority, size_t stack_size)
	Starts the thread.

virtual	~OSThread ()
	Default destructor.

bool	is_created ()

void	inherit ()
	Inherits the current thread.

os_thread_t	get_handle ()

void	lock_to_thread ()
	Sets the thread handle to the current calling thread's.

void	unlock_from_thread ()
	Resets the thread handle to none.

Static Public Attributes
static constexpr size_t	NUM_CHANNELS = 16
	maximum number of PWM channels supported by the PCA9685

static constexpr size_t	MAX_PWM_COUNTS = 4096
	maximum number of PWM counts supported by the PCA9685

Private Types
enum	Registers { MODE1 = 0 , MODE2 , LED0_ON_L = 6 , PRE_SCALE = 254 }
	Important device register offsets. More...

Private Member Functions
void *	entry () override
	User entry point for the created thread.

void	bit_modify (Registers address, uint8_t data, uint8_t mask)
	Bit modify to an I2C register.

void	set_pwm_duty (unsigned channel, uint16_t counts)
	Set the pwm duty cycle.

uint16_t	get_pwm_duty (unsigned channel)
	Get the pwm duty cycle.

void	write_pwm_duty (unsigned channel, uint16_t counts)
	Set the pwm duty cycle.

void	register_write (Registers address, uint8_t data)
	Write to an I2C register.

void	register_write_multiple (Registers address, void *data, size_t count)
	Write to multiple sequential I2C registers.

	DISALLOW_COPY_AND_ASSIGN (PCA9685PWM)

Private Attributes
friend	PCA9685PWMBit
	Allow access to private members.

OSSem	sem_
	Wakeup for the thread processing.

int	i2c_
	I2C file descriptor.

std::array< uint16_t, NUM_CHANNELS >	duty_
	local cache of the duty cycles

uint16_t	dirty_
	set if the duty_ value is updated (bit mask)

uint8_t	i2cAddress_
	I2C address of the device.

Additional Inherited Members
Static Public Member Functions inherited from OSThread
static int	getpriority (OSThread *thread)
	Return the current thread priority.

static int	get_priority (OSThread *thread)
	Return the current thread priority.

static int	get_priority_min ()
	Get the minimum thread priority.

static int	get_priority_max ()
	Get the maximum thread priority.

Detailed Description

Agragate of 16 PWM channels for a PCA9685PWM.

Definition at line 48 of file PCA9685PWM.hxx.

Member Enumeration Documentation

◆ Registers

enum PCA9685PWM::Registers

private

Important device register offsets.

Enumerator
MODE1	mode 1 settings
MODE2	mode 2 settings
LED0_ON_L	first LED control register
PRE_SCALE	clock prescale divider

Definition at line 119 of file PCA9685PWM.hxx.

Constructor & Destructor Documentation

◆ PCA9685PWM()

PCA9685PWM::PCA9685PWM ( )

inline

Constructor.

Definition at line 58 of file PCA9685PWM.hxx.

◆ ~PCA9685PWM()

PCA9685PWM::~PCA9685PWM ( )

inline

Destructor.

Definition at line 113 of file PCA9685PWM.hxx.

Member Function Documentation

◆ bit_modify()

void PCA9685PWM::bit_modify	(	Registers	address,
		uint8_t	data,
		uint8_t	mask
	)

inlineprivate

Bit modify to an I2C register.

Parameters

address	address to modify
data	data to modify
mask	mask of data to modify, bits where mask is 1 will be overwritten, bits where mask is zero will be kept

Definition at line 218 of file PCA9685PWM.hxx.

◆ entry()

void * PCA9685PWM::entry ( )

overrideprivatevirtual

User entry point for the created thread.

Returns: exit status

Reimplemented from OSThread.

Definition at line 39 of file PCA9685PWM.cxx.

◆ get_pwm_duty()

uint16_t PCA9685PWM::get_pwm_duty ( unsigned channel )

inlineprivate

Get the pwm duty cycle.

Parameters

channel channel index (0 through 15)

Returns: counts for PWM duty cycle

Definition at line 267 of file PCA9685PWM.hxx.

◆ init()

void PCA9685PWM::init	(	const char *	name,
		uint8_t	i2c_address,
		uint16_t	pwm_freq = `200`,
		int32_t	external_clock_freq = `-1`
	)

inline

Initialize device.

Parameters

name	name of the I2C device
i2c_address	I2C address of the device on the bus
pwm_frequency	target PWM frequency (will truncate at minimum and maximum prescaler values)
external_clock	frequency of an external clock in Hz, -1 if internal clock is used

Definition at line 74 of file PCA9685PWM.hxx.

◆ register_write()

void PCA9685PWM::register_write	(	Registers	address,
		uint8_t	data
	)

inlineprivate

Write to an I2C register.

Parameters

address	address to write to
data	data to write

Definition at line 307 of file PCA9685PWM.hxx.

◆ register_write_multiple()

void PCA9685PWM::register_write_multiple	(	Registers	address,
		void *	data,
		size_t	count
	)

inlineprivate

Write to multiple sequential I2C registers.

Parameters

address	address to start write at
data	array of data to write
count	number of data registers to write in sequence

Definition at line 317 of file PCA9685PWM.hxx.

◆ set_pwm_duty()

void PCA9685PWM::set_pwm_duty	(	unsigned	channel,
		uint16_t	counts
	)

inlineprivate

Set the pwm duty cycle.

Parameters

channel	channel index (0 through 15)
counts	counts for PWM duty cycle

Definition at line 252 of file PCA9685PWM.hxx.

◆ write_pwm_duty()

void PCA9685PWM::write_pwm_duty	(	unsigned	channel,
		uint16_t	counts
	)

inlineprivate

Set the pwm duty cycle.

Parameters

channel	channel index (0 through 15)
counts	counts for PWM duty cycle

Definition at line 276 of file PCA9685PWM.hxx.

Member Data Documentation

◆ dirty_

uint16_t PCA9685PWM::dirty_

private

set if the duty_ value is updated (bit mask)

Definition at line 338 of file PCA9685PWM.hxx.

◆ duty_

std::array<uint16_t, NUM_CHANNELS> PCA9685PWM::duty_

private

local cache of the duty cycles

Definition at line 335 of file PCA9685PWM.hxx.

◆ i2c_

int PCA9685PWM::i2c_

private

I2C file descriptor.

Definition at line 332 of file PCA9685PWM.hxx.

◆ i2cAddress_

uint8_t PCA9685PWM::i2cAddress_

private

I2C address of the device.

Definition at line 341 of file PCA9685PWM.hxx.

◆ MAX_PWM_COUNTS

constexpr size_t PCA9685PWM::MAX_PWM_COUNTS = 4096

staticconstexpr

maximum number of PWM counts supported by the PCA9685

Definition at line 55 of file PCA9685PWM.hxx.

◆ NUM_CHANNELS

constexpr size_t PCA9685PWM::NUM_CHANNELS = 16

staticconstexpr

maximum number of PWM channels supported by the PCA9685

Definition at line 52 of file PCA9685PWM.hxx.

◆ PCA9685PWMBit

friend PCA9685PWM::PCA9685PWMBit

private

Allow access to private members.

Definition at line 326 of file PCA9685PWM.hxx.

◆ sem_

OSSem PCA9685PWM::sem_

private

Wakeup for the thread processing.

Definition at line 329 of file PCA9685PWM.hxx.

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

Classes

Public Member Functions

Static Public Attributes

Private Types

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ Registers

Constructor & Destructor Documentation

◆ PCA9685PWM()

◆ ~PCA9685PWM()

Member Function Documentation

◆ bit_modify()

◆ entry()

◆ get_pwm_duty()

◆ init()

◆ register_write()

◆ register_write_multiple()

◆ set_pwm_duty()

◆ write_pwm_duty()

Member Data Documentation

◆ dirty_

◆ duty_

◆ i2c_

◆ i2cAddress_

◆ MAX_PWM_COUNTS

◆ NUM_CHANNELS

◆ PCA9685PWMBit

◆ sem_