i2cslave.h File Reference

Creates an I2C slave device with 32-byte registers that an I2C master device can write to and read from with a 7-bit device ID, 1-bit read/write, 8-bit register address, and 8 bits of data. More...

#include "simpletools.h"

Go to the source code of this file.

Functions
i2cslave_t *	i2cslave_open (int pin_clock, int pin_data, int address)
	Start an I2C slave processor in a new cog. More...
void	i2cslave_close (i2cslave_t *device)
	Stop the I2C slave processor and make cog and memory resources available for other uses. More...
char *	i2cslave_regAddr (i2cslave_t *device)
	Provides a pointer to the first of the I2C slave device's 32 byte registers. Applications can use this address to directly access the registers without making method calls. More...
int	i2cslave_checkForRegChange (i2cslave_t *device)
	Check if any registers have changed. If a register has changed, return its number. If more than one register has changed, return the highest address that has changed. If no registers have changed, return -1. More...
int	i2cslave_checkReg (i2cslave_t *device, int index)
	Get the register value if it has changed. More...
int	i2cslave_checkFlags (i2cslave_t *device)
	Check the flags register. Bits 31 to 0 indicate if data has changed in registers 31 to 0. More...
int	i2cslave_checkFlag (i2cslave_t *device, int index)
	Check a certain register's flag. More...
void	i2cslave_clearFlag (i2cslave_t *device, int index)
	Clear a certain register's flag. More...
char	i2cslave_getReg (i2cslave_t *device, int index)
	Get the value stored by a certain register. More...
void	i2cslave_putReg (i2cslave_t *device, int index, int value)
	Set the value of a register. More...
void	i2cslave_flush (i2cslave_t *device)
	Clear all register values and flags. More...
int	bitwiseEncode (int i)
	Find out the highest bit with a 1 in a 32 bit register. More...

Detailed Description

Creates an I2C slave device with 32-byte registers that an I2C master device can write to and read from with a 7-bit device ID, 1-bit read/write, 8-bit register address, and 8 bits of data.

Author

PASM Chris Gadd, Andy Lindsay Spin to C interface port.

Copyright

Parallax Inc. 2018, MIT License at end of file.

Function Documentation

bitwiseEncode()

int bitwiseEncode

(

int

i

)

Find out the highest bit with a 1 in a 32 bit register.

Returns

index The number of the highest bit (31 to 0) that stores a 1 in a given 32 bit variable.

i2cslave_checkFlag()

int i2cslave_checkFlag	(	i2cslave_t *	device,
		int	index
	)

Check a certain register's flag.

Parameters

*device	The i2slave process identifier returned by i2cslave_start.
index	The index of the flag to be checked.

Returns

status 1 if the register has changed since the last time it was read of 0 if it has not.

i2cslave_checkFlags()

int i2cslave_checkFlags

(

i2cslave_t *

device

)

Check the flags register. Bits 31 to 0 indicate if data has changed in registers 31 to 0.

Parameters

*device

The i2slave process identifier returned by i2cslave_start.

Returns

flags Contents of the 32 bit flags register.

i2cslave_checkForRegChange()

int i2cslave_checkForRegChange

(

i2cslave_t *

device

)

Check if any registers have changed. If a register has changed, return its number. If more than one register has changed, return the highest address that has changed. If no registers have changed, return -1.

Parameters

*device

The i2slave process identifier returned by i2cslave_start.

Returns

number (0 to 31) of the highest value that has changed since the last checkForRegChange call.

i2cslave_checkReg()

int i2cslave_checkReg	(	i2cslave_t *	device,
		int	index
	)

Get the register value if it has changed.

Parameters

*device	The i2slave process identifier returned by i2cslave_start.
index	The index (0 to 31) of the register to check.

Returns

value The new register value, or -1 if the register has not changed.

i2cslave_clearFlag()

void i2cslave_clearFlag	(	i2cslave_t *	device,
		int	index
	)

Clear a certain register's flag.

Parameters

*device	The i2slave process identifier returned by i2cslave_start.
index	The index of the flag to be cleared.

i2cslave_close()

void i2cslave_close

(

i2cslave_t *

device

)

Stop the I2C slave processor and make cog and memory resources available for other uses.

Parameters

*device

The i2slave process identifier returned by i2cslave_start.

i2cslave_flush()

void i2cslave_flush

(

i2cslave_t *

device

)

Clear all register values and flags.

Parameters

*device

The i2slave process identifier returned by i2cslave_start.

i2cslave_getReg()

char i2cslave_getReg	(	i2cslave_t *	device,
		int	index
	)

Get the value stored by a certain register.

Parameters

*device	The i2slave process identifier returned by i2cslave_start.
index	The index of the register (0 to 31).

Returns

The value stored by the register.

i2cslave_open()

i2cslave_t* i2cslave_open	(	int	pin_clock,
		int	pin_data,
		int	address
	)

Start an I2C slave processor in a new cog.

Parameters

pin_clock	I2C bus clock pin
pin_data	I2C bus data pin
address	7-bit I2C address for slave device.

Returns

i2cslave process identifier for other i2cslave_* function calls.

i2cslave_putReg()

void i2cslave_putReg	(	i2cslave_t *	device,
		int	index,
		int	value
	)

Set the value of a register.

Parameters

*device	The i2slave process identifier returned by i2cslave_start.
index	The index of the register (0 to 31).
value	The value stored by the register.

i2cslave_regAddr()

char* i2cslave_regAddr

(

i2cslave_t *

device

)

Provides a pointer to the first of the I2C slave device's 32 byte registers. Applications can use this address to directly access the registers without making method calls.

Returns

char pointer to the first of 32 byte registers.