HalI2cPca9685Comm Class Reference

Concrete I2C communication adapter for PCA9685 using BaseI2c. More...

#include <Pca9685Handler.h>

Inheritance diagram for HalI2cPca9685Comm:

Public Member Functions
	HalI2cPca9685Comm (BaseI2c &i2c_device) noexcept
	Construct the I2C communication adapter.
CRTP-Required Methods
Called by pca9685::I2cInterface<HalI2cPca9685Comm> via static dispatch.
bool	Write (uint8_t addr, uint8_t reg, const uint8_t *data, size_t len) noexcept
	Write data to a device register.
bool	Read (uint8_t addr, uint8_t reg, uint8_t *data, size_t len) noexcept
	Read data from a device register.
bool	EnsureInitialized () noexcept
	Ensure the I2C bus is initialized and ready.
void	DelayUs (uint32_t us) noexcept
	Optional driver hook: wait at least us microseconds.

Private Attributes
BaseI2c &	i2c_device_
	I2C device interface (not owned).
RtosMutex	i2c_mutex_
	Thread safety for I2C operations.

Detailed Description

Concrete I2C communication adapter for PCA9685 using BaseI2c.

Implements all methods required by pca9685::I2cInterface<HalI2cPca9685Comm> through the CRTP pattern. This class bridges the HardFOC BaseI2c device interface (where the I2C address is pre-configured on the device) with the PCA9685 driver's I2C interface (which passes the address as a parameter).

Key behaviors:

• Address validation: Every write/read validates that the driver's address matches the BaseI2c device's configured address.
• Register framing: Writes are framed as [register, data...] per I2C convention.
• Thread safety: All I2C operations are mutex-protected.
• Lazy initialization: EnsureInitialized() delegates to BaseI2c.

Note

This class does NOT own the BaseI2c device; it must remain valid for the lifetime of this adapter.

See also

pca9685::I2cInterface CRTP base class from the PCA9685 driver

Constructor & Destructor Documentation

HalI2cPca9685Comm()

HalI2cPca9685Comm::HalI2cPca9685Comm ( BaseI2c &  i2c_device )

explicitnoexcept

Construct the I2C communication adapter.

Parameters

i2c_device

Reference to a BaseI2c device with pre-configured address.

Warning

The BaseI2c device must outlive this adapter.

Member Function Documentation

DelayUs()

void HalI2cPca9685Comm::DelayUs ( uint32_t  us )

noexcept

Optional driver hook: wait at least us microseconds.

The driver waits the 500 µs oscillator start-up after clearing MODE1.SLEEP (Wake(), SetPwmFreq(), Reset()) through it, before it writes RESTART (datasheet Table 5 note 2).

EnsureInitialized()

bool HalI2cPca9685Comm::EnsureInitialized ( )

noexcept

Ensure the I2C bus is initialized and ready.

Returns

true if the BaseI2c device is initialized or was initialized successfully.

Read()

bool HalI2cPca9685Comm::Read ( uint8_t  addr, uint8_t  reg, uint8_t *  data, size_t  len  )

noexcept

Read data from a device register.

Sends the register address via BaseI2c::WriteRead() and reads back data.

Parameters

addr	7-bit I2C address (validated against BaseI2c device).
reg	Register address to read from.
data	Buffer to store read data.
len	Number of bytes to read.

Returns

true if read succeeded, false on address mismatch or I2C error.

Write()

bool HalI2cPca9685Comm::Write ( uint8_t  addr, uint8_t  reg, const uint8_t *  data, size_t  len  )

noexcept

Write data to a device register.

Frames the write as [register_address, data...] and sends via BaseI2c::Write().

Parameters

addr	7-bit I2C address (validated against BaseI2c device).
reg	Register address to write to.
data	Pointer to data buffer.
len	Number of bytes to write.

Returns

true if write succeeded, false on address mismatch or I2C error.

Member Data Documentation

i2c_device_

BaseI2c& HalI2cPca9685Comm::i2c_device_

private

I2C device interface (not owned).

i2c_mutex_

RtosMutex HalI2cPca9685Comm::i2c_mutex_

mutableprivate

Thread safety for I2C operations.

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

• Pca9685Handler.h
• Pca9685Handler.cpp