PortI2C Class Reference

Can be used to drive a software (bit-banged) I2C bus via a Port interface. More...

#include <Ports.h>

Inheritance diagram for PortI2C:

Public Types
enum	{ KHZMAX = 1, KHZ400 = 2, KHZ100 = 9 }

Public Member Functions
	PortI2C (uint8_t num, uint8_t rate=KHZMAX)
	Creates an instance of class PortI2C. More...
uint8_t	start (uint8_t addr) const
	Initalize I2C communication on a JeeNode port. More...
void	stop () const
	Terminate transmission on an I2C connection.
uint8_t	write (uint8_t data) const
	Send one byte of data to the currently address I2C device. More...
uint8_t	read (uint8_t last) const
	Read a byte using I2C protocol on a JeeNode port. More...
Public Member Functions inherited from Port
	Port (uint8_t num)
	Contructor for a Port.
void	mode (uint8_t value) const
	Set the pin mode of a Port's D pin. More...
uint8_t	digiRead () const
	Reads the value of a Port's D pin. More...
void	digiWrite (uint8_t value) const
	Write High or Low to a Port's D pin. More...
void	anaWrite (uint8_t val) const
	Writes a PWM value to a Port's D pin.
uint32_t	pulse (uint8_t state, uint32_t timeout=1000000L) const
	Applies the Arduino pulseIn() function on a Port's D pin. More...
void	mode2 (uint8_t value) const
	Set the pin mode of a Port's A pin. More...
uint16_t	anaRead () const
	Reads an analog value from a Port's A pin. More...
uint8_t	digiRead2 () const
	Reads the value of a Port's A pin. More...
void	digiWrite2 (uint8_t value) const
	Write High or Low to a Port's A pin. More...
uint32_t	pulse2 (uint8_t state, uint32_t timeout=1000000L) const
	Applies the Arduino pulseIn() function on a Port's A pin. More...
void	shift (uint8_t bitOrder, uint8_t value) const
	Does Arduino shiftOut() with data on D and clock on A pin of the Port. More...
uint16_t	shiftRead (uint8_t bitOrder, uint8_t count=8) const
	Shift a number of bites in to read them. More...
void	shiftWrite (uint8_t bitOrder, uint16_t value, uint8_t count=8) const
	The shiftWrite() call is similar but more general than the shift() call in that it allows an adjustable number of bits to be sent, not just 8. More...

Additional Inherited Members
Static Public Member Functions inherited from Port
static void	mode3 (uint8_t value)
	Set the pin mode of the I pin on all Ports. More...
static uint8_t	digiRead3 ()
	Reads the value of the I pin on all Ports. More...
static void	digiWrite3 (uint8_t value)
	Writes the value of the I pin on all Ports. More...
static void	anaWrite3 (uint8_t val)
	Writes a PWM value to the I pin of all Ports.
Protected Member Functions inherited from Port
uint8_t	digiPin () const
uint8_t	digiPin2 () const
uint8_t	anaPin () const
Static Protected Member Functions inherited from Port
static uint8_t	digiPin3 ()
Protected Attributes inherited from Port
uint8_t	portNum
	The port number is a small integer mathing the hardware port used. More...

Detailed Description

Can be used to drive a software (bit-banged) I2C bus via a Port interface.

Todo:

Speed up the I2C bit I/O, it's far too slow right now.

The PortI2C class is a special version of class Port implementing the I2C / Two-Wire Interface (TWI) protocol. Allows using any port as I2C bus master. When used for I2C, DIO is used as SDA and AIO as SCL. Unlike the Wire library for the Arduino, which is a more advanced solution for the hardware I2C lines of an ATmega, the PortI2C class is implemented entirely in software using "bit-banging". Another difference is that PortI2C does not use interrupts and will keep the microcontroller occupied while it is performing I/O transfers.

See Also

DeviceI2C

Constructor & Destructor Documentation

PortI2C::PortI2C	(	uint8_t	num,
		uint8_t	rate = KHZMAX
	)

Creates an instance of class PortI2C.

Parameters

num	port number corresponding to physical JeeNode port number.
rate	in microseconds - time delay between bits? (not quite!)

Member Function Documentation

uint8_t PortI2C::read

(

uint8_t

last

)

const

Read a byte using I2C protocol on a JeeNode port.

Parameters

last	pass 1 to signal the last byte read in this bus transaction

Returns

data (byte) read from the I2C device

uint8_t PortI2C::start

(

uint8_t

addr

)

const

Initalize I2C communication on a JeeNode port.

Parameters

addr	I2C address of device with which to communicate

Returns

1 if communication succeeded, 0 otherwise

uint8_t PortI2C::write

(

uint8_t

data

)

const

Send one byte of data to the currently address I2C device.

Parameters

data	the data byte to send out

Returns

1 if device acknowledged write, 0 if device did not respond

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

• Ports.h
• Ports.cpp