Basic I2C driver. More...

#include <PropWare/serial/i2c/i2cmaster.h>

Collaboration diagram for PropWare::I2CMaster:

Public Member Functions
	I2CMaster (const Pin::Mask sclMask=DEFAULT_SCL_MASK, const Pin::Mask sdaMask=DEFAULT_SDA_MASK, const unsigned int frequency=DEFAULT_FREQUENCY)
	Create a basic I2C instance. More...

void	set_frequency (const unsigned int frequency)
	Set the bus frequency. More...

void	start () const
	Output a start condition on the I2C bus.

void	stop () const
	Output a stop condition on the I2C bus.

bool	send_byte (const uint8_t byte) const
	Output a byte on the I2C bus. More...

uint8_t	read_byte (const bool acknowledge) const
	Get a byte from the bus. More...

bool	ping (const uint8_t device) const
	Test for the Acknowledge of a device by sending start and the slave address. More...

template<typename T >
bool	put (const uint8_t device, const T address, const uint8_t byte) const
	Put a single byte with the following format: More...

template<typename T >
uint8_t	get (const uint8_t device, const T address) const
	Get a single byte with the following format: More...

template<typename T >
bool	put (const uint8_t device, const T address, const uint8_t bytes[], const size_t size) const
	Put multiple bytes with the following format: More...

template<typename T >
bool	get (const uint8_t device, const T address, uint8_t bytes[], const size_t size) const
	Read multiple bytes. More...

bool	put (const uint8_t device, const uint8_t byte) const
	Put a single byte, no register address, on the bus. More...

bool	get (const uint8_t device, uint8_t bytes[], const size_t size) const
	Get multiple bytes, no register address. More...

Static Public Attributes
static const Pin::Mask	DEFAULT_SCL_MASK = Pin::Mask::P28

static const Pin::Mask	DEFAULT_SDA_MASK = Pin::Mask::P29

static const unsigned int	DEFAULT_FREQUENCY = 400000

Detailed Description

Basic I2C driver.

Requires that the SDA and SCL pins have sufficient pullups. These should be selected based on the capacitance of the devices on the I2C bus, and the expected clock speed (400kHz currently).

All "device" fields should be the 7 bit address of the device, with the low bit set to 0 (the 7 addres bits are the upper bits). This applies to both the Put (write) and Get (read) cases.

Put and Get are based on I2C communication specification as described by ST in the LSM303DLHC and L3GD20 datasheets. Terms:

ST - Start
SAD - Slave Address (device)
SAK - Slave Acknowledge
SUB - SubAddress (slave register address)
SP - Stop
+W - plus write (lowest device bit set to 0)
+R - plus read (lowest device bit set to 1)
NMAK - Master No Acknowledge

I2C differs based on the device that you use. For functions that might be device specific, there is a reference indicator. These references are:

ST - ST Microelectronics, particularly the LSM303DLHC and L3GD20 devices.
MS - Measurement Specialties, particularly the MS5607 and MS5611 devices.

If you're using the multibyte Get and Put with ST based devices, be sure to bitwise OR the register address with 0x80 (the MSb to 1) in order to turn on the auto-increment function (see datasheet for L3GD20 for example). This is not done automatically by this library.

Examples: I2CSlave_Demo.cpp, and PropWareI2C_Demo.cpp.

Definition at line 64 of file i2cmaster.h.

Constructor & Destructor Documentation

◆ I2CMaster()

PropWare::I2CMaster::I2CMaster	(	const Pin::Mask	sclMask = `DEFAULT_SCL_MASK`,
		const Pin::Mask	sdaMask = `DEFAULT_SDA_MASK`,
		const unsigned int	frequency = `DEFAULT_FREQUENCY`
	)

Create a basic I2C instance.

Parameters

[in]	sclMask	Pin mask for the SCL pin (default value uses the EEPROM SCL line)
[in]	sdaMask	Pin mask for the SDA pin (default value uses the EEPROM SDA line)
[in]	frequency	Frequency to run the bus (default is highest standard I2C frequency of 400 kHz)

Definition at line 78 of file i2cmaster.h.

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Member Function Documentation

◆ get() [1/3]

template<typename T >

uint8_t PropWare::I2CMaster::get	(	const uint8_t	device,
		const T	address
	)		const

Get a single byte with the following format:

+-----—+-—+----—+--—+--—+--—+-—+----—+--—+---—+---—+-—+ | Master | ST | SAD+W | | SUB | | ST | SAD+R | | | NMAK | SP | | Slave | | | SAK | | SAK | | | SAK | DATA | | | +-----—+-—+----—+--—+--—+--—+-—+----—+--—+---—+---—+-—+

Reference: ST

Parameters

[in]	device	7 bit slave I2C address (in bits 7-1, with bit 0 set to 0)
[in]	address	slave register address

Returns: the 8 bits of data read from register address.

Definition at line 327 of file i2cmaster.h.

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◆ get() [2/3]

template<typename T >

bool PropWare::I2CMaster::get	(	const uint8_t	device,
		const T	address,
		uint8_t	bytes[],
		const size_t	size
	)		const

Read multiple bytes.

Get multiple bytes with the following format:

                                                        |Repeat for # of bytes -1 | Last byte   |

+-----—+-—+----—+--—+--—+--—+-—+----—+--—+---—+--—+---—+--—+---—+---—+-—+ | Master | ST | SAD+W | | SUB | | ST | SAD+R | | | MAK | | MAK | | NMAK | SP | | Slave | | | SAK | | SAK | | | SAK | DATA | | DATA | | DATA | | | +-----—+-—+----—+--—+--—+--—+-—+----—+--—+---—+--—+---—+--—+---—+---—+-—+

Reference: ST

Parameters

[in]	device	the 7 bit slave I2C address (in bits 7-1, with bit 0 set to 0).
[in]	address	the 8 bit slave register address.
[out]	bytes	the address to begin storing the read bytes at.
[in]	size	the number of bytes to read.

Returns: false if one or more nAcks is received, true otherwise

Definition at line 408 of file i2cmaster.h.

◆ get() [3/3]

bool PropWare::I2CMaster::get	(	const uint8_t	device,
		uint8_t	bytes[],
		const size_t	size
	)		const

Get multiple bytes, no register address.

Reference: MS Follows the format:

                         |Repeat      |

+-----—+-—+----—+--—+---—+--—+---—+---—+-—+ | Master | ST | SAD+R | | | MAK | | NMAK | SP | | Slave | | | SAK | DATA | | DATA | | | +-----—+-—+----—+--—+---—+--—+---—+---—+-—+

Warning: Notice the lack of a specified register!

Parameters

[in]	device	the 7 bit slave I2C address (in bits 7-1, with bit 0 set to 0)
[out]	bytes	the address to begin storing the read bytes at.
[in]	size	the number of bytes to read.

Returns: false if one or more nAcks is received, true otherwise

Definition at line 483 of file i2cmaster.h.

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◆ ping()

bool PropWare::I2CMaster::ping ( const uint8_t device ) const

Test for the Acknowledge of a device by sending start and the slave address.

Useful for polling the bus and seeing what devices are available. Ping uses the following format:

+-----—+-—+----—+--—+-—+ | Master | ST | SAD+W | | SP | | Slave | | | SAK | | +-----—+-—+----—+--—+-—+

Parameters

[in] device 7-bit shifted address device (in bits 7-1, not 6-0)

Returns: true if ack was received, false otherwise

Definition at line 272 of file i2cmaster.h.

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◆ put() [1/3]

template<typename T >

bool PropWare::I2CMaster::put	(	const uint8_t	device,
		const T	address,
		const uint8_t	byte
	)		const

Put a single byte with the following format:

+-----—+-—+----—+--—+--—+--—+---—+--—+-—+ | Master | ST | SAD+W | | SUB | | BYTE | | SP | | Slave | | | SAK | | SAK | | SAK | | +-----—+-—+----—+--—+--—+--—+---—+--—+-—+

Reference: ST

Parameters

[in]	device	7 bit slave I2C address (in bits 7-1, with bit 0 set to 0)
[in]	address	slave register address
[in]	byte	8 bits of data to store at `address`

Returns: false if one or more nAcks is received, true otherwise

Definition at line 296 of file i2cmaster.h.

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◆ put() [2/3]

template<typename T >

bool PropWare::I2CMaster::put	(	const uint8_t	device,
		const T	address,
		const uint8_t	bytes[],
		const size_t	size
	)		const

Put multiple bytes with the following format:

                                     |Repeat for # of bytes    |

+-----—+-—+----—+--—+--—+--—+---—+--—+---—+--—+-—+ | Master | ST | SAD+W | | SUB | | DATA | | DATA | | SP | | Slave | | | SAK | | SAK | | SAK | | SAK | | +-----—+-—+----—+--—+--—+--—+---—+--—+---—+--—+-—+

Reference: ST

Parameters

[in]	device	7 bit slave I2C address (in bits 7-1, with bit 0 set to 0)
[in]	address	slave register address
[in]	bytes	set of bytes to store on device, starting at register address.
[in]	size	number of bytes to write

Returns: false if one or more nAcks is received, true otherwise

Definition at line 367 of file i2cmaster.h.

◆ put() [3/3]

bool PropWare::I2CMaster::put	(	const uint8_t	device,
		const uint8_t	byte
	)		const

Put a single byte, no register address, on the bus.

Follows the format:

+-----—+-—+----—+--—+---—+--—+-—+ | Master | ST | SAD+W | | DATA | | SP | | Slave | | | SAK | | SAK | | +-----—+-—+----—+--—+---—+--—+-—+

Reference: MS

Warning: Notice the lack of a specified register!

Parameters

[in]	device	the 7 bit slave I2C address (in bits 7-1, with bit 0 set to 0)
[in]	byte	the 8 bits of data to send to device

Returns: false if one or more nAcks is received, true otherwise

Definition at line 450 of file i2cmaster.h.

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◆ read_byte()

uint8_t PropWare::I2CMaster::read_byte ( const bool acknowledge ) const

Get a byte from the bus.

Parameters

[in] acknowledge true to acknowledge the byte received, false otherwise

Returns: Byte clocked in from the bus

Definition at line 197 of file i2cmaster.h.

◆ send_byte()

bool PropWare::I2CMaster::send_byte ( const uint8_t byte ) const

Output a byte on the I2C bus.

Parameters

[in] byte 8 bits to send on the bus

Returns: true if the device acknowledges, false otherwise

Definition at line 134 of file i2cmaster.h.

◆ set_frequency()

void PropWare::I2CMaster::set_frequency ( const unsigned int frequency )

Set the bus frequency.

Parameters

[in] frequency Frequency in Hz to run the bus

Definition at line 94 of file i2cmaster.h.

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

PropWare/serial/i2c/i2cmaster.h

Public Member Functions

Static Public Attributes

Detailed Description

Constructor & Destructor Documentation

◆ I2CMaster()

Member Function Documentation

◆ get() [1/3]

◆ get() [2/3]

◆ get() [3/3]

◆ ping()

◆ put() [1/3]

◆ put() [2/3]

◆ put() [3/3]

◆ read_byte()

◆ send_byte()

◆ set_frequency()