m5::unit::AdapterI2C Class Reference

I2C access adapter. More...

#include <adapter_i2c.hpp>

Inheritance diagram for m5::unit::AdapterI2C:

Classes
class	BusImpl
class	I2CClassImpl
class	I2CImpl

Public Types
enum class	ImplType : uint8_t { Unknown , TwoWire , Bus , I2CClass }
	I2C implementation type. More...
Public Types inherited from m5::unit::Adapter
enum class	Type : uint8_t {   Unknown , I2C , GPIO , UART ,   SPI }
	Adapter type. More...

Public Member Functions
	AdapterI2C (m5::hal::bus::Bus *bus, const uint8_t addr, const uint32_t clock)
	AdapterI2C (m5::I2C_Class &i2c, const uint8_t addr, const uint32_t clock)
	AdapterI2C (m5::hal::bus::Bus &bus, const uint8_t addr, const uint32_t clock)
I2CImpl *	impl ()
const I2CImpl *	impl () const
uint8_t	address () const
void	setAddress (const uint8_t addr)
uint32_t	clock () const
void	setClock (const uint32_t clock)
ImplType	implType () const
	Gets the I2C implementation type.
int16_t	port () const
	I2C port number, or -1 if unknown (TwoWire, Bus, or a bus handle added without its port)
int16_t	scl () const
int16_t	sda () const
virtual Adapter *	duplicate (const uint8_t addr) override
	Create a duplicate adapter with a different address.
bool	releasePins ()
	Detach SDA/SCL from the I2C controller and make them GPIO.
bool	restorePins ()
	Reattach SDA/SCL to the I2C controller as they were before releasePins()
Temporary API
Warning Functionality required for a specific unit Will be improved when integrated with M5HAL
bool	begin ()
bool	end ()
bool	pushPin ()
bool	popPin ()
Public Member Functions inherited from m5::unit::Adapter
	Adapter ()
	Default constructor (creates Unknown type adapter)
	Adapter (const Adapter &)=delete
	Adapter (Adapter &&) noexcept=default
Adapter &	operator= (const Adapter &)=delete
Adapter &	operator= (Adapter &&) noexcept=default
Type	type () const
	Gets the adapter type.
virtual void	beginTransaction ()
	Begin a bus transaction.
virtual void	endTransaction ()
	End a bus transaction.
m5::hal::error::error_t	readWithTransaction (uint8_t *data, const size_t len)
	Read data within a transaction.
m5::hal::error::error_t	writeWithTransaction (const uint8_t *data, const size_t len, const uint32_t exparam=1)
	Read data within a transaction.
m5::hal::error::error_t	writeWithTransaction (const uint8_t reg, const uint8_t *data, const size_t len, const uint32_t exparam=1)
	Read data within a transaction.
m5::hal::error::error_t	writeWithTransaction (const uint16_t reg, const uint8_t *data, const size_t len, const uint32_t exparam=1)
	Read data within a transaction.
m5::hal::error::error_t	generalCall (const uint8_t *data, const size_t len)
	Send a general call on the I2C bus.
m5::hal::error::error_t	writeDigitalRX (const bool high)
m5::hal::error::error_t	readDigitalRX (bool &high)
m5::hal::error::error_t	writeAnalogRX (const uint16_t v)
m5::hal::error::error_t	readAnalogRX (uint16_t &v)
m5::hal::error::error_t	readAnalogMilliVoltsRX (uint32_t &mv)
m5::hal::error::error_t	pulseInRX (uint32_t &duration, const int state, const uint32_t timeout_us)
m5::hal::error::error_t	writeDigitalTX (const bool high)
m5::hal::error::error_t	readDigitalTX (bool &high)
m5::hal::error::error_t	writeAnalogTX (const uint16_t v)
m5::hal::error::error_t	readAnalogTX (uint16_t &v)
m5::hal::error::error_t	readAnalogMilliVoltsTX (uint32_t &mv)
m5::hal::error::error_t	pulseInTX (uint32_t &duration, const int state, const uint32_t timeout_us)

Protected Attributes
gpio::pin_backup_t	_backupSCL {-1}
gpio::pin_backup_t	_backupSDA {-1}
Protected Attributes inherited from m5::unit::Adapter
std::unique_ptr< Impl >	_impl {}

Additional Inherited Members
Protected Member Functions inherited from m5::unit::Adapter
	Adapter (const Type t, Impl *impl)

Detailed Description

I2C access adapter.

Member Enumeration Documentation

ImplType

enum class m5::unit::AdapterI2C::ImplType : uint8_t

strong

I2C implementation type.

Enumerator
Unknown	Unknown.
TwoWire	Arduino TwoWire.
Bus	M5HAL Bus (including SoftwareI2C)
I2CClass	m5::I2C_Class (m5gfx::i2c)

Member Function Documentation

duplicate()

Adapter * m5::unit::AdapterI2C::duplicate ( const uint8_t )

overridevirtual

Create a duplicate adapter with a different address.

Reimplemented from m5::unit::Adapter.

releasePins()

bool m5::unit::AdapterI2C::releasePins

(

)

Detach SDA/SCL from the I2C controller and make them GPIO.

For sending a frame an I2C controller cannot send (e.g. a few bits, no address). SDA/SCL become open-drain GPIO outputs, left high with the internal pull-ups, and the controller is fed an idle (high) bus so it does not take the GPIO waveform as bus traffic. Drive them with the GPIO API (gpio_set_level etc.), then call restorePins()

Returns

True if successful. False (with nothing changed) if

• SDA/SCL are unknown (sda() / scl() return -1, e.g. add(unit, bus) without the port and pins)
• the pins are not routed through the GPIO matrix: LP I2C on its fixed pads (ESP32-C6 / C5 Wire1, ESP-IDF LP_I2C_NUM_0) and ESP32-P4 GPIO0-15 used as LP IO
• the build is not for ESP (native / host)

Note

A software bus (M5HAL Bus) has no controller to detach, so its pins are just made GPIO

Warning

Do not access any unit on the same bus until restorePins()

restorePins()

bool m5::unit::AdapterI2C::restorePins

(

)

Reattach SDA/SCL to the I2C controller as they were before releasePins()

Returns

True if successful