twi_basics/twi_basics.c File Reference

#include "twi_basics.h"
#include <util/twi.h>

Go to the source code of this file.

Defines
#define	TW_CONF_MASK   ((1<<TWWC) | (1<<TWEN) | (1<<TWIE) | (1<<1) )
#define	TW_SEND_CMD(cmd)   TWCR = (TWCR & TW_CONF_MASK ) | (cmd)
	sends command leaving CONF bits unchanged
Functions
void	wait ()
twi_status	twi_start ()
twi_status	twi_send (uint8_t data)
twi_status	twi_receive (uint8_t *where, uint8_t ack)
void	twi_stop ()

---

Detailed Description

Author:

Krzysztof Wesolowski

Date:

September 09, 2009

Definition in file twi_basics.c.

---

Define Documentation

#define TW_CONF_MASK   ((1<<TWWC) | (1<<TWEN) | (1<<TWIE) | (1<<1) )

those bits should be unchanged while writing commands to TWCR, so we will simple write (TCWR & TW_CONF_MASK) | Command

Definition at line 12 of file twi_basics.c.

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Function Documentation

twi_status twi_receive	(	uint8_t *	where,
		uint8_t	ack
	)

Receive one byte over TWI interface

Parameters:

	where	Pointer to location where received data we'll be stored
	ack	Set to nonzero to send ACK after receiving. Usually it continues transfer.

Returns:

Status of TWI after operation extracted from TWSR

Definition at line 54 of file twi_basics.c.

References TW_SEND_CMD, and wait().

Referenced by ds1338_readBufferFromNVRAM(), and ds1338_readByteFromNVRAM().

twi_status twi_send

(

uint8_t

data

)

Sends one byte over TWI interface

Parameters:

data

Data to be send

Returns:

Status of TWI after operation extracted from TWSR

Definition at line 40 of file twi_basics.c.

References TW_SEND_CMD, and wait().

Referenced by ds1338_writeBufferToNVRAM(), and ds1338_writeByteToNVRAM().

twi_status twi_start

(

)

Sends start condition

Returns:

Status of TWI after operation extracted from TWSR

Definition at line 28 of file twi_basics.c.

References TW_SEND_CMD, and wait().

void twi_stop

(

)

Sends STOP condition. Take a look at unusual busy-wait loop (Stop doesn't affect TWINT)

Definition at line 68 of file twi_basics.c.

References TW_SEND_CMD.

Referenced by ds1338_readBufferFromNVRAM(), ds1338_readByteFromNVRAM(), ds1338_writeBufferToNVRAM(), and ds1338_writeByteToNVRAM().

void wait

(

)

Waits until last TWI operation is completed

Definition at line 19 of file twi_basics.c.

Referenced by twi_receive(), twi_send(), and twi_start().