Друзья подскажите как обмениваться данными с часами DS1307 через функции avrlib Раньше писал с CodeVision там программный I2C и библиотека под часы была но пришлось перейти на AVR Studio так как библиотеки avrlib есть графический дисплей вот что то пытался написать но не работает не пойму как пользоваться I2C Библиотекой в итоге этого исходника ничего не происходит хотя импульсы на выходе контроллера есть (mega128) FCpu=8мгц В переменных нули =(((



i2cSetBitrate(50);
i2cInit();


while(1)
{


i2cSendStart();
_delay_ms(100);
i2cSendByte(0xd0);
_delay_ms(100);
i2cSendByte(0);
_delay_ms(100);
i2cSendStart();
_delay_ms(100);
i2cSendByte(0xd1);
_delay_ms(100);
sek= i2cGetReceivedByte();
min= i2cGetReceivedByte();
hour= i2cGetReceivedByte();


i2cSendStop();

Уважаемый Дима 128, сообщество будет благодарно, если Вы будете соблюдать нормы русского языка. Например, расставлять знаки припинания Без них, поверьте, понять смылс иной раз невозможно (Казнить нельзя помиловать).

По теме: Вам следует почиать стандарт на шину I2C. Там описаны старт условия, стоп условия, когда необходимо подтвержать прием, когда нет. Как мне кажется, задержки в 100 мс - совершенно лишние. Аппаратный модуль TWI в микроконтроллере сделает все "сам".

Успехов!

По теме: Вам следует почиать стандарт на шину I2C. Там описаны старт условия, стоп условия, когда необходимо подтвержать прием, когда нет. Как мне кажется, задержки в 100 мс - совершенно лишние. Аппаратный модуль TWI в микроконтроллере сделает все "сам".

Успехов!


Ну эта задержка уже так для эксперимента =))) Я читал про модуль и на ассемблере его запускал но хотелось бы узнать как
функцией avrlib пользоваться раз она там есть уж =)))


Или AVR Studio + avrlib не наш метод?

Для какого эксперимента? Шина I2C до нескольких сотен килобит работает)


У меня нет avrlib( Если речь об avrlibc из WinAVR, то не могу найти указанные функции. У меня WinAVR20071221.


Да это-то тут при чем? Используйте то, что Вам удобнее.

Попробуйте посмотреть на форуме подобные темы.

Народ не одну сотню DS1307 запустил)))

Я тоже с ней работал, но это было давно ( 5 лет назад ). Исходников не осталось, к сожалению, иначе бы с удовольствием поделился бы)))

Так вот и я запускал не одни часы =))) Но в CodeVision там вообще своя библиотека под них есть, но нет хорошей библиотеки для работы с графическим дисплеем, переписывать под CodeVision, avrlib библиотеку графического дисплея, еще хуже чем разобраться с функциями I2C Я просто не очень давно на си пишу и строчки длинные с математическими действиями над регистром меня ставят иногда в тупик =)))

Пробовал вот так
rs&=3;
if (sqwe) rs|=0x10;
if (out) rs|=0x80;
i2cSendStart();
i2cWaitForComplete();
i2cSendByte(0xd0);
i2cWaitForComplete();


i2cSendByte(7);
i2cWaitForComplete();
i2cSendByte(rs);
i2cWaitForComplete();
i2cSendStop();
Инициализация

И прочитать

i2cSendStart();
i2cWaitForComplete();
i2cSendByte(0xd0);
i2cWaitForComplete();
i2cSendByte(0);
i2cWaitForComplete();
i2cSendStart();
i2cWaitForComplete();
i2cSendByte(0xd1);
i2cWaitForComplete();
*sec=i2cGetReceivedByte(1);
i2cWaitForComplete();
*min=i2cGetReceivedByte(1);
i2cWaitForComplete();
*hour=i2cGetReceivedByte(0);
i2cWaitForComplete();
i2cSendStop();


И не получается =)))

Я имел в виду, что запускал часики без использования библиотек. Т.е. библиотеки писал самостоятельно.

Ну не писать же библиотеку I2C С нуля если она там есть просто не совсем ясно как пользоваться ей =)))

А чего там писать? Аппаратный модуль сам все сделает. Почитайте документацию, придет понимание, потом и библиотеку прикрутите)))

Вот писать программный I2C - это да, трудно! Хотя, если честно, тоже просто Я где-то в прикрепленной теме (библиотеки полезных программ) лет 5 назад выкладывал библиотеку, которая и аппаратный TWI использует, и позволяет программно шину реализовать.

Если же хочется использовать именно avrlib, то читайте документацию. Там все должно быть.

Ну, а для полного понимания - спецификацию на шину I2C. Я уже Вам это советовал. Когда-то все равно придется это сделать.

Да я на ассемблере запускал его соответственно знаком с этим но что в библиотеки сишной, трудно понять для меня =))

Неужели никто не использовал avrlib?

А вы пробовали проверить значение ACK бита которое отдает вам DS1307? Это дало бы какую то информацию. И неплохо знать что какой ACK вы отдаете при чтении.
Еще вот что я думаю. После передачи D0, 00 вы передаете сразу старт условие. А может стоило бы сначала стоп передать?

Вы про бит чтения.запись? Там получается что у устройства адрес 1101000 семи разрядный + бит этот получается 11010000=0xd0 Я на основе примера из CodeVisin пытался сделать там часы работают

i2c_start();
i2c_write(0xd0);
i2c_write(0);
i2c_start();
i2c_write(0xd1);
*sec=bcd2bin(i2c_read(1));
*min=bcd2bin(i2c_read(1));
*hour=bcd2bin(i2c_read(0));
i2c_stop();


А вот как это с функциями из avrlib это проделать не знаю что то упускаю пробовал вот так


i2cSetBitrate(100);
i2cInit();


i2cSendStart();

i2cSendByte(0xD0);

i2cSendByte(0);

i2cSendStop();

i2cSendStart();

i2cSendByte(0xD1);

sek=i2cGetReceivedByte();

i2cSendStop();


Но где то ошибка есть =(((



Вот функции которые есть в avrlib

// functions

//! Initialize I2C (TWI) interface
void i2cInit(void);

//! Set the I2C transaction bitrate (in KHz)
void i2cSetBitrate(u16 bitrateKHz);

// I2C setup and configurations commands
//! Set the local (AVR processor's) I2C device address
void i2cSetLocalDeviceAddr(u08 deviceAddr, u08 genCallEn);

//! Set the user function which handles receiving (incoming) data as a slave
void i2cSetSlaveReceiveHandler(void (*i2cSlaveRx_func)(u08 receiveDataLength, u08* recieveData));
//! Set the user function which handles transmitting (outgoing) data as a slave
void i2cSetSlaveTransmitHandler(u08 (*i2cSlaveTx_func)(u08 transmitDataLengthMax, u08* transmitData));

// Low-level I2C transaction commands
//! Send an I2C start condition in Master mode
void i2cSendStart(void);
//! Send an I2C stop condition in Master mode
void i2cSendStop(void);
//! Wait for current I2C operation to complete
void i2cWaitForComplete(void);
//! Send an (address|R/W) combination or a data byte over I2C
void i2cSendByte(u08 data);
//! Receive a data byte over I2C
// ackFlag = TRUE if recevied data should be ACK'ed
// ackFlag = FALSE if recevied data should be NACK'ed
void i2cReceiveByte(u08 ackFlag);
//! Pick up the data that was received with i2cReceiveByte()
u08 i2cGetReceivedByte(void);
//! Get current I2c bus status from TWSR
u08 i2cGetStatus(void);

// high-level I2C transaction commands

//! send I2C data to a device on the bus
void i2cMasterSend(u08 deviceAddr, u08 length, u08 *data);
//! receive I2C data from a device on the bus
void i2cMasterReceive(u08 deviceAddr, u08 length, u08* data);

//! send I2C data to a device on the bus (non-interrupt based)
u08 i2cMasterSendNI(u08 deviceAddr, u08 length, u08* data);
//! receive I2C data from a device on the bus (non-interrupt based)
u08 i2cMasterReceiveNI(u08 deviceAddr, u08 length, u08 *data);

//! Get the current high-level state of the I2C interface
eI2cStateType i2cGetState(void);

#endif

Нет, я про бит ACK, который идет после бита чтение-запись. Он 9-й по счету. Вам надо читать стандарт I2C, там это написано. И в ваших исходниках реализация этого бита не видна. Может даже ваш контроллер не формирует такт для него из за чего сбивается весь протокол.

Как же реализовать это в этих функциях? Я думал там это уже все есть =)))

Поэтому надо писать свои функции. Для I2C это не сложно.

Да наверно придется что то самому придумать =(((

Вот функции из сишного файла





#include <avr/io.h>
#include <avr/interrupt.h>

#include "i2c.h"

#include "rprintf.h" // include printf function library
#include "uart2.h"

// Standard I2C bit rates are:
// 100KHz for slow speed
// 400KHz for high speed

//#define I2C_DEBUG

// I2C state and address variables
static volatile eI2cStateType I2cState;
static u08 I2cDeviceAddrRW;
// send/transmit buffer (outgoing data)
static u08 I2cSendData[I2C_SEND_DATA_BUFFER_SIZE];
static u08 I2cSendDataIndex;
static u08 I2cSendDataLength;
// receive buffer (incoming data)
static u08 I2cReceiveData[I2C_RECEIVE_DATA_BUFFER_SIZE];
static u08 I2cReceiveDataIndex;
static u08 I2cReceiveDataLength;

// function pointer to i2c receive routine
//! I2cSlaveReceive is called when this processor
// is addressed as a slave for writing
static void (*i2cSlaveReceive)(u08 receiveDataLength, u08* recieveData);
//! I2cSlaveTransmit is called when this processor
// is addressed as a slave for reading
static u08 (*i2cSlaveTransmit)(u08 transmitDataLengthMax, u08* transmitData);

// functions
void i2cInit(void)
{
// set pull-up resistors on I2C bus pins
// TODO: should #ifdef these
sbi(PORTC, 0); // i2c SCL on ATmega163,323,16,32,etc
sbi(PORTC, 1); // i2c SDA on ATmega163,323,16,32,etc
sbi(PORTD, 0); // i2c SCL on ATmega128,64
sbi(PORTD, 1); // i2c SDA on ATmega128,64

// clear SlaveReceive and SlaveTransmit handler to null
i2cSlaveReceive = 0;
i2cSlaveTransmit = 0;
// set i2c bit rate to 100KHz
i2cSetBitrate(100);
// enable TWI (two-wire interface)
sbi(TWCR, TWEN);
// set state
I2cState = I2C_IDLE;
// enable TWI interrupt and slave address ACK
sbi(TWCR, TWIE);
sbi(TWCR, TWEA);
//outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
// enable interrupts
sei();
}

void i2cSetBitrate(u16 bitrateKHz)
{
u08 bitrate_div;
// set i2c bitrate
// SCL freq = F_CPU/(16+2*TWBR))
#ifdef TWPS0
// for processors with additional bitrate division (mega128)
// SCL freq = F_CPU/(16+2*TWBR*4^TWPS)
// set TWPS to zero
cbi(TWSR, TWPS0);
cbi(TWSR, TWPS1);
#endif
// calculate bitrate division
bitrate_div = ((F_CPU/1000l)/bitrateKHz);
if(bitrate_div >= 16)
bitrate_div = (bitrate_div-16)/2;
outb(TWBR, bitrate_div);
}

void i2cSetLocalDeviceAddr(u08 deviceAddr, u08 genCallEn)
{
// set local device address (used in slave mode only)
outb(TWAR, ((deviceAddr&0xFE) | (genCallEn?1:0)) );
}

void i2cSetSlaveReceiveHandler(void (*i2cSlaveRx_func)(u08 receiveDataLength, u08* recieveData))
{
i2cSlaveReceive = i2cSlaveRx_func;
}

void i2cSetSlaveTransmitHandler(u08 (*i2cSlaveTx_func)(u08 transmitDataLengthMax, u08* transmitData))
{
i2cSlaveTransmit = i2cSlaveTx_func;
}

inline void i2cSendStart(void)
{
// send start condition
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWSTA));
}

inline void i2cSendStop(void)
{
// transmit stop condition
// leave with TWEA on for slave receiving
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA)|BV(TWSTO));
}

inline void i2cWaitForComplete(void)
{
// wait for i2c interface to complete operation
while( !(inb(TWCR) & BV(TWINT)) );
}

inline void i2cSendByte(u08 data)
{
// save data to the TWDR
outb(TWDR, data);
// begin send
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT));
}

inline void i2cReceiveByte(u08 ackFlag)
{
// begin receive over i2c
if( ackFlag )
{
// ackFlag = TRUE: ACK the recevied data
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
}
else
{
// ackFlag = FALSE: NACK the recevied data
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT));
}
}

inline u08 i2cGetReceivedByte(void)
{
// retieve received data byte from i2c TWDR
return( inb(TWDR) );
}

inline u08 i2cGetStatus(void)
{
// retieve current i2c status from i2c TWSR
return( inb(TWSR) );
}

void i2cMasterSend(u08 deviceAddr, u08 length, u08* data)
{
u08 i;
// wait for interface to be ready
while(I2cState);
// set state
I2cState = I2C_MASTER_TX;
// save data
I2cDeviceAddrRW = (deviceAddr & 0xFE); // RW cleared: write operation
for(i=0; i<length; i++)
I2cSendData[i] = *data++;
I2cSendDataIndex = 0;
I2cSendDataLength = length;
// send start condition
i2cSendStart();
}

void i2cMasterReceive(u08 deviceAddr, u08 length, u08* data)
{
u08 i;
// wait for interface to be ready
while(I2cState);
// set state
I2cState = I2C_MASTER_RX;
// save data
I2cDeviceAddrRW = (deviceAddr|0x01); // RW set: read operation
I2cReceiveDataIndex = 0;
I2cReceiveDataLength = length;
// send start condition
i2cSendStart();
// wait for data
while(I2cState);
// return data
for(i=0; i<length; i++)
*data++ = I2cReceiveData[i];
}

u08 i2cMasterSendNI(u08 deviceAddr, u08 length, u08* data)
{
u08 retval = I2C_OK;

// disable TWI interrupt
cbi(TWCR, TWIE);

// send start condition
i2cSendStart();
i2cWaitForComplete();

// send device address with write
i2cSendByte( deviceAddr & 0xFE );
i2cWaitForComplete();

// check if device is present and live
if( inb(TWSR) == TW_MT_SLA_ACK)
{
// send data
while(length)
{
i2cSendByte( *data++ );
i2cWaitForComplete();
length--;
}
}
else
{
// device did not ACK it's address,
// data will not be transferred
// return error
retval = I2C_ERROR_NODEV;
}

// transmit stop condition
// leave with TWEA on for slave receiving
i2cSendStop();
while( !(inb(TWCR) & BV(TWSTO)) );

// enable TWI interrupt
sbi(TWCR, TWIE);

return retval;
}

u08 i2cMasterReceiveNI(u08 deviceAddr, u08 length, u08 *data)
{
u08 retval = I2C_OK;

// disable TWI interrupt
cbi(TWCR, TWIE);

// send start condition
i2cSendStart();
i2cWaitForComplete();

// send device address with read
i2cSendByte( deviceAddr | 0x01 );
i2cWaitForComplete();

// check if device is present and live
if( inb(TWSR) == TW_MR_SLA_ACK)
{
// accept receive data and ack it
while(length > 1)
{
i2cReceiveByte(TRUE);
i2cWaitForComplete();
*data++ = i2cGetReceivedByte();
// decrement length
length--;
}

// accept receive data and nack it (last-byte signal)
i2cReceiveByte(FALSE);
i2cWaitForComplete();
*data++ = i2cGetReceivedByte();
}
else
{
// device did not ACK it's address,
// data will not be transferred
// return error
retval = I2C_ERROR_NODEV;
}

// transmit stop condition
// leave with TWEA on for slave receiving
i2cSendStop();

// enable TWI interrupt
sbi(TWCR, TWIE);

return retval;
}
/*
void i2cMasterTransferNI(u08 deviceAddr, u08 sendlength, u08* senddata, u08 receivelength, u08* receivedata)
{
// disable TWI interrupt
cbi(TWCR, TWIE);

// send start condition
i2cSendStart();
i2cWaitForComplete();

// if there's data to be sent, do it
if(sendlength)
{
// send device address with write
i2cSendByte( deviceAddr & 0xFE );
i2cWaitForComplete();

// send data
while(sendlength)
{
i2cSendByte( *senddata++ );
i2cWaitForComplete();
sendlength--;
}
}

// if there's data to be received, do it
if(receivelength)
{
// send repeated start condition
i2cSendStart();
i2cWaitForComplete();

// send device address with read
i2cSendByte( deviceAddr | 0x01 );
i2cWaitForComplete();

// accept receive data and ack it
while(receivelength > 1)
{
i2cReceiveByte(TRUE);
i2cWaitForComplete();
*receivedata++ = i2cGetReceivedByte();
// decrement length
receivelength--;
}

// accept receive data and nack it (last-byte signal)
i2cReceiveByte(TRUE);
i2cWaitForComplete();
*receivedata++ = i2cGetReceivedByte();
}

// transmit stop condition
// leave with TWEA on for slave receiving
i2cSendStop();
while( !(inb(TWCR) & BV(TWSTO)) );

// enable TWI interrupt
sbi(TWCR, TWIE);
}
*/

//! I2C (TWI) interrupt service routine
SIGNAL(SIG_2WIRE_SERIAL)
{
// read status bits
u08 status = inb(TWSR) & TWSR_STATUS_MASK;

switch(status)
{
// Master General
case TW_START: // 0x08: Sent start condition
case TW_REP_START: // 0x10: Sent repeated start condition
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: M->START\r\n");
rprintfInit(uart1SendByte);
#endif
// send device address
i2cSendByte(I2cDeviceAddrRW);
break;

// Master Transmitter & Receiver status codes
case TW_MT_SLA_ACK: // 0x18: Slave address acknowledged
case TW_MT_DATA_ACK: // 0x28: Data acknowledged
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: MT->SLA_ACK or DATA_ACK\r\n");
rprintfInit(uart1SendByte);
#endif
if(I2cSendDataIndex < I2cSendDataLength)
{
// send data
i2cSendByte( I2cSendData[I2cSendDataIndex++] );
}
else
{
// transmit stop condition, enable SLA ACK
i2cSendStop();
// set state
I2cState = I2C_IDLE;
}
break;
case TW_MR_DATA_NACK: // 0x58: Data received, NACK reply issued
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: MR->DATA_NACK\r\n");
rprintfInit(uart1SendByte);
#endif
// store final received data byte
I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
// continue to transmit STOP condition
case TW_MR_SLA_NACK: // 0x48: Slave address not acknowledged
case TW_MT_SLA_NACK: // 0x20: Slave address not acknowledged
case TW_MT_DATA_NACK: // 0x30: Data not acknowledged
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: MTR->SLA_NACK or MT->DATA_NACK\r\n");
rprintfInit(uart1SendByte);
#endif
// transmit stop condition, enable SLA ACK
i2cSendStop();
// set state
I2cState = I2C_IDLE;
break;
case TW_MT_ARB_LOST: // 0x38: Bus arbitration lost
//case TW_MR_ARB_LOST: // 0x38: Bus arbitration lost
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: MT->ARB_LOST\r\n");
rprintfInit(uart1SendByte);
#endif
// release bus
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT));
// set state
I2cState = I2C_IDLE;
// release bus and transmit start when bus is free
//outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWSTA));
break;
case TW_MR_DATA_ACK: // 0x50: Data acknowledged
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: MR->DATA_ACK\r\n");
rprintfInit(uart1SendByte);
#endif
// store received data byte
I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
// fall-through to see if more bytes will be received
case TW_MR_SLA_ACK: // 0x40: Slave address acknowledged
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: MR->SLA_ACK\r\n");
rprintfInit(uart1SendByte);
#endif
if(I2cReceiveDataIndex < (I2cReceiveDataLength-1))
// data byte will be received, reply with ACK (more bytes in transfer)
i2cReceiveByte(TRUE);
else
// data byte will be received, reply with NACK (final byte in transfer)
i2cReceiveByte(FALSE);
break;

// Slave Receiver status codes
case TW_SR_SLA_ACK: // 0x60: own SLA+W has been received, ACK has been returned
case TW_SR_ARB_LOST_SLA_ACK: // 0x68: own SLA+W has been received, ACK has been returned
case TW_SR_GCALL_ACK: // 0x70: GCA+W has been received, ACK has been returned
case TW_SR_ARB_LOST_GCALL_ACK: // 0x78: GCA+W has been received, ACK has been returned
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: SR->SLA_ACK\r\n");
rprintfInit(uart1SendByte);
#endif
// we are being addressed as slave for writing (data will be received from master)
// set state
I2cState = I2C_SLAVE_RX;
// prepare buffer
I2cReceiveDataIndex = 0;
// receive data byte and return ACK
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
break;
case TW_SR_DATA_ACK: // 0x80: data byte has been received, ACK has been returned
case TW_SR_GCALL_DATA_ACK: // 0x90: data byte has been received, ACK has been returned
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: SR->DATA_ACK\r\n");
rprintfInit(uart1SendByte);
#endif
// get previously received data byte
I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
// check receive buffer status
if(I2cReceiveDataIndex < I2C_RECEIVE_DATA_BUFFER_SIZE)
{
// receive data byte and return ACK
i2cReceiveByte(TRUE);
//outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
}
else
{
// receive data byte and return NACK
i2cReceiveByte(FALSE);
//outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT));
}
break;
case TW_SR_DATA_NACK: // 0x88: data byte has been received, NACK has been returned
case TW_SR_GCALL_DATA_NACK: // 0x98: data byte has been received, NACK has been returned
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: SR->DATA_NACK\r\n");
rprintfInit(uart1SendByte);
#endif
// receive data byte and return NACK
i2cReceiveByte(FALSE);
//outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT));
break;
case TW_SR_STOP: // 0xA0: STOP or REPEATED START has been received while addressed as slave
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: SR->SR_STOP\r\n");
rprintfInit(uart1SendByte);
#endif
// switch to SR mode with SLA ACK
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
// i2c receive is complete, call i2cSlaveReceive
if(i2cSlaveReceive) i2cSlaveReceive(I2cReceiveDataIndex, I2cReceiveData);
// set state
I2cState = I2C_IDLE;
break;

// Slave Transmitter
case TW_ST_SLA_ACK: // 0xA8: own SLA+R has been received, ACK has been returned
case TW_ST_ARB_LOST_SLA_ACK: // 0xB0: GCA+R has been received, ACK has been returned
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: ST->SLA_ACK\r\n");
rprintfInit(uart1SendByte);
#endif
// we are being addressed as slave for reading (data must be transmitted back to master)
// set state
I2cState = I2C_SLAVE_TX;
// request data from application
if(i2cSlaveTransmit) I2cSendDataLength = i2cSlaveTransmit(I2C_SEND_DATA_BUFFER_SIZE, I2cSendData);
// reset data index
I2cSendDataIndex = 0;
// fall-through to transmit first data byte
case TW_ST_DATA_ACK: // 0xB8: data byte has been transmitted, ACK has been received
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: ST->DATA_ACK\r\n");
rprintfInit(uart1SendByte);
#endif
// transmit data byte
outb(TWDR, I2cSendData[I2cSendDataIndex++]);
if(I2cSendDataIndex < I2cSendDataLength)
// expect ACK to data byte
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
else
// expect NACK to data byte
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT));
break;
case TW_ST_DATA_NACK: // 0xC0: data byte has been transmitted, NACK has been received
case TW_ST_LAST_DATA: // 0xC8:
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: ST->DATA_NACK or LAST_DATA\r\n");
rprintfInit(uart1SendByte);
#endif
// all done
// switch to open slave
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
// set state
I2cState = I2C_IDLE;
break;

// Misc
case TW_NO_INFO: // 0xF8: No relevant state information
// do nothing
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: NO_INFO\r\n");
rprintfInit(uart1SendByte);
#endif
break;
case TW_BUS_ERROR: // 0x00: Bus error due to illegal start or stop condition
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: BUS_ERROR\r\n");
rprintfInit(uart1SendByte);
#endif
// reset internal hardware and release bus
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWSTO)|BV(TWEA));
// set state
I2cState = I2C_IDLE;
break;
}
}

eI2cStateType i2cGetState(void)
{
return I2cState;
}


Вот функции из сишного файла





#include <avr/io.h>
#include <avr/interrupt.h>

#include "i2c.h"

#include "rprintf.h" // include printf function library
#include "uart2.h"

// Standard I2C bit rates are:
// 100KHz for slow speed
// 400KHz for high speed

//#define I2C_DEBUG

// I2C state and address variables
static volatile eI2cStateType I2cState;
static u08 I2cDeviceAddrRW;
// send/transmit buffer (outgoing data)
static u08 I2cSendData[I2C_SEND_DATA_BUFFER_SIZE];
static u08 I2cSendDataIndex;
static u08 I2cSendDataLength;
// receive buffer (incoming data)
static u08 I2cReceiveData[I2C_RECEIVE_DATA_BUFFER_SIZE];
static u08 I2cReceiveDataIndex;
static u08 I2cReceiveDataLength;

// function pointer to i2c receive routine
//! I2cSlaveReceive is called when this processor
// is addressed as a slave for writing
static void (*i2cSlaveReceive)(u08 receiveDataLength, u08* recieveData);
//! I2cSlaveTransmit is called when this processor
// is addressed as a slave for reading
static u08 (*i2cSlaveTransmit)(u08 transmitDataLengthMax, u08* transmitData);

// functions
void i2cInit(void)
{
// set pull-up resistors on I2C bus pins
// TODO: should #ifdef these
sbi(PORTC, 0); // i2c SCL on ATmega163,323,16,32,etc
sbi(PORTC, 1); // i2c SDA on ATmega163,323,16,32,etc
sbi(PORTD, 0); // i2c SCL on ATmega128,64
sbi(PORTD, 1); // i2c SDA on ATmega128,64

// clear SlaveReceive and SlaveTransmit handler to null
i2cSlaveReceive = 0;
i2cSlaveTransmit = 0;
// set i2c bit rate to 100KHz
i2cSetBitrate(100);
// enable TWI (two-wire interface)
sbi(TWCR, TWEN);
// set state
I2cState = I2C_IDLE;
// enable TWI interrupt and slave address ACK
sbi(TWCR, TWIE);
sbi(TWCR, TWEA);
//outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
// enable interrupts
sei();
}

void i2cSetBitrate(u16 bitrateKHz)
{
u08 bitrate_div;
// set i2c bitrate
// SCL freq = F_CPU/(16+2*TWBR))
#ifdef TWPS0
// for processors with additional bitrate division (mega128)
// SCL freq = F_CPU/(16+2*TWBR*4^TWPS)
// set TWPS to zero
cbi(TWSR, TWPS0);
cbi(TWSR, TWPS1);
#endif
// calculate bitrate division
bitrate_div = ((F_CPU/1000l)/bitrateKHz);
if(bitrate_div >= 16)
bitrate_div = (bitrate_div-16)/2;
outb(TWBR, bitrate_div);
}

void i2cSetLocalDeviceAddr(u08 deviceAddr, u08 genCallEn)
{
// set local device address (used in slave mode only)
outb(TWAR, ((deviceAddr&0xFE) | (genCallEn?1:0)) );
}

void i2cSetSlaveReceiveHandler(void (*i2cSlaveRx_func)(u08 receiveDataLength, u08* recieveData))
{
i2cSlaveReceive = i2cSlaveRx_func;
}

void i2cSetSlaveTransmitHandler(u08 (*i2cSlaveTx_func)(u08 transmitDataLengthMax, u08* transmitData))
{
i2cSlaveTransmit = i2cSlaveTx_func;
}

inline void i2cSendStart(void)
{
// send start condition
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWSTA));
}

inline void i2cSendStop(void)
{
// transmit stop condition
// leave with TWEA on for slave receiving
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA)|BV(TWSTO));
}

inline void i2cWaitForComplete(void)
{
// wait for i2c interface to complete operation
while( !(inb(TWCR) & BV(TWINT)) );
}

inline void i2cSendByte(u08 data)
{
// save data to the TWDR
outb(TWDR, data);
// begin send
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT));
}

inline void i2cReceiveByte(u08 ackFlag)
{
// begin receive over i2c
if( ackFlag )
{
// ackFlag = TRUE: ACK the recevied data
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
}
else
{
// ackFlag = FALSE: NACK the recevied data
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT));
}
}

inline u08 i2cGetReceivedByte(void)
{
// retieve received data byte from i2c TWDR
return( inb(TWDR) );
}

inline u08 i2cGetStatus(void)
{
// retieve current i2c status from i2c TWSR
return( inb(TWSR) );
}

void i2cMasterSend(u08 deviceAddr, u08 length, u08* data)
{
u08 i;
// wait for interface to be ready
while(I2cState);
// set state
I2cState = I2C_MASTER_TX;
// save data
I2cDeviceAddrRW = (deviceAddr & 0xFE); // RW cleared: write operation
for(i=0; i<length; i++)
I2cSendData[i] = *data++;
I2cSendDataIndex = 0;
I2cSendDataLength = length;
// send start condition
i2cSendStart();
}

void i2cMasterReceive(u08 deviceAddr, u08 length, u08* data)
{
u08 i;
// wait for interface to be ready
while(I2cState);
// set state
I2cState = I2C_MASTER_RX;
// save data
I2cDeviceAddrRW = (deviceAddr|0x01); // RW set: read operation
I2cReceiveDataIndex = 0;
I2cReceiveDataLength = length;
// send start condition
i2cSendStart();
// wait for data
while(I2cState);
// return data
for(i=0; i<length; i++)
*data++ = I2cReceiveData[i];
}

u08 i2cMasterSendNI(u08 deviceAddr, u08 length, u08* data)
{
u08 retval = I2C_OK;

// disable TWI interrupt
cbi(TWCR, TWIE);

// send start condition
i2cSendStart();
i2cWaitForComplete();

// send device address with write
i2cSendByte( deviceAddr & 0xFE );
i2cWaitForComplete();

// check if device is present and live
if( inb(TWSR) == TW_MT_SLA_ACK)
{
// send data
while(length)
{
i2cSendByte( *data++ );
i2cWaitForComplete();
length--;
}
}
else
{
// device did not ACK it's address,
// data will not be transferred
// return error
retval = I2C_ERROR_NODEV;
}

// transmit stop condition
// leave with TWEA on for slave receiving
i2cSendStop();
while( !(inb(TWCR) & BV(TWSTO)) );

// enable TWI interrupt
sbi(TWCR, TWIE);

return retval;
}

u08 i2cMasterReceiveNI(u08 deviceAddr, u08 length, u08 *data)
{
u08 retval = I2C_OK;

// disable TWI interrupt
cbi(TWCR, TWIE);

// send start condition
i2cSendStart();
i2cWaitForComplete();

// send device address with read
i2cSendByte( deviceAddr | 0x01 );
i2cWaitForComplete();

// check if device is present and live
if( inb(TWSR) == TW_MR_SLA_ACK)
{
// accept receive data and ack it
while(length > 1)
{
i2cReceiveByte(TRUE);
i2cWaitForComplete();
*data++ = i2cGetReceivedByte();
// decrement length
length--;
}

// accept receive data and nack it (last-byte signal)
i2cReceiveByte(FALSE);
i2cWaitForComplete();
*data++ = i2cGetReceivedByte();
}
else
{
// device did not ACK it's address,
// data will not be transferred
// return error
retval = I2C_ERROR_NODEV;
}

// transmit stop condition
// leave with TWEA on for slave receiving
i2cSendStop();

// enable TWI interrupt
sbi(TWCR, TWIE);

return retval;
}
/*
void i2cMasterTransferNI(u08 deviceAddr, u08 sendlength, u08* senddata, u08 receivelength, u08* receivedata)
{
// disable TWI interrupt
cbi(TWCR, TWIE);

// send start condition
i2cSendStart();
i2cWaitForComplete();

// if there's data to be sent, do it
if(sendlength)
{
// send device address with write
i2cSendByte( deviceAddr & 0xFE );
i2cWaitForComplete();

// send data
while(sendlength)
{
i2cSendByte( *senddata++ );
i2cWaitForComplete();
sendlength--;
}
}

// if there's data to be received, do it
if(receivelength)
{
// send repeated start condition
i2cSendStart();
i2cWaitForComplete();

// send device address with read
i2cSendByte( deviceAddr | 0x01 );
i2cWaitForComplete();

// accept receive data and ack it
while(receivelength > 1)
{
i2cReceiveByte(TRUE);
i2cWaitForComplete();
*receivedata++ = i2cGetReceivedByte();
// decrement length
receivelength--;
}

// accept receive data and nack it (last-byte signal)
i2cReceiveByte(TRUE);
i2cWaitForComplete();
*receivedata++ = i2cGetReceivedByte();
}

// transmit stop condition
// leave with TWEA on for slave receiving
i2cSendStop();
while( !(inb(TWCR) & BV(TWSTO)) );

// enable TWI interrupt
sbi(TWCR, TWIE);
}
*/

//! I2C (TWI) interrupt service routine
SIGNAL(SIG_2WIRE_SERIAL)
{
// read status bits
u08 status = inb(TWSR) & TWSR_STATUS_MASK;

switch(status)
{
// Master General
case TW_START: // 0x08: Sent start condition
case TW_REP_START: // 0x10: Sent repeated start condition
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: M->START\r\n");
rprintfInit(uart1SendByte);
#endif
// send device address
i2cSendByte(I2cDeviceAddrRW);
break;

// Master Transmitter & Receiver status codes
case TW_MT_SLA_ACK: // 0x18: Slave address acknowledged
case TW_MT_DATA_ACK: // 0x28: Data acknowledged
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: MT->SLA_ACK or DATA_ACK\r\n");
rprintfInit(uart1SendByte);
#endif
if(I2cSendDataIndex < I2cSendDataLength)
{
// send data
i2cSendByte( I2cSendData[I2cSendDataIndex++] );
}
else
{
// transmit stop condition, enable SLA ACK
i2cSendStop();
// set state
I2cState = I2C_IDLE;
}
break;
case TW_MR_DATA_NACK: // 0x58: Data received, NACK reply issued
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: MR->DATA_NACK\r\n");
rprintfInit(uart1SendByte);
#endif
// store final received data byte
I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
// continue to transmit STOP condition
case TW_MR_SLA_NACK: // 0x48: Slave address not acknowledged
case TW_MT_SLA_NACK: // 0x20: Slave address not acknowledged
case TW_MT_DATA_NACK: // 0x30: Data not acknowledged
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: MTR->SLA_NACK or MT->DATA_NACK\r\n");
rprintfInit(uart1SendByte);
#endif
// transmit stop condition, enable SLA ACK
i2cSendStop();
// set state
I2cState = I2C_IDLE;
break;
case TW_MT_ARB_LOST: // 0x38: Bus arbitration lost
//case TW_MR_ARB_LOST: // 0x38: Bus arbitration lost
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: MT->ARB_LOST\r\n");
rprintfInit(uart1SendByte);
#endif
// release bus
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT));
// set state
I2cState = I2C_IDLE;
// release bus and transmit start when bus is free
//outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWSTA));
break;
case TW_MR_DATA_ACK: // 0x50: Data acknowledged
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: MR->DATA_ACK\r\n");
rprintfInit(uart1SendByte);
#endif
// store received data byte
I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
// fall-through to see if more bytes will be received
case TW_MR_SLA_ACK: // 0x40: Slave address acknowledged
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: MR->SLA_ACK\r\n");
rprintfInit(uart1SendByte);
#endif
if(I2cReceiveDataIndex < (I2cReceiveDataLength-1))
// data byte will be received, reply with ACK (more bytes in transfer)
i2cReceiveByte(TRUE);
else
// data byte will be received, reply with NACK (final byte in transfer)
i2cReceiveByte(FALSE);
break;

// Slave Receiver status codes
case TW_SR_SLA_ACK: // 0x60: own SLA+W has been received, ACK has been returned
case TW_SR_ARB_LOST_SLA_ACK: // 0x68: own SLA+W has been received, ACK has been returned
case TW_SR_GCALL_ACK: // 0x70: GCA+W has been received, ACK has been returned
case TW_SR_ARB_LOST_GCALL_ACK: // 0x78: GCA+W has been received, ACK has been returned
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: SR->SLA_ACK\r\n");
rprintfInit(uart1SendByte);
#endif
// we are being addressed as slave for writing (data will be received from master)
// set state
I2cState = I2C_SLAVE_RX;
// prepare buffer
I2cReceiveDataIndex = 0;
// receive data byte and return ACK
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
break;
case TW_SR_DATA_ACK: // 0x80: data byte has been received, ACK has been returned
case TW_SR_GCALL_DATA_ACK: // 0x90: data byte has been received, ACK has been returned
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: SR->DATA_ACK\r\n");
rprintfInit(uart1SendByte);
#endif
// get previously received data byte
I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
// check receive buffer status
if(I2cReceiveDataIndex < I2C_RECEIVE_DATA_BUFFER_SIZE)
{
// receive data byte and return ACK
i2cReceiveByte(TRUE);
//outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
}
else
{
// receive data byte and return NACK
i2cReceiveByte(FALSE);
//outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT));
}
break;
case TW_SR_DATA_NACK: // 0x88: data byte has been received, NACK has been returned
case TW_SR_GCALL_DATA_NACK: // 0x98: data byte has been received, NACK has been returned
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: SR->DATA_NACK\r\n");
rprintfInit(uart1SendByte);
#endif
// receive data byte and return NACK
i2cReceiveByte(FALSE);
//outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT));
break;
case TW_SR_STOP: // 0xA0: STOP or REPEATED START has been received while addressed as slave
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: SR->SR_STOP\r\n");
rprintfInit(uart1SendByte);
#endif
// switch to SR mode with SLA ACK
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
// i2c receive is complete, call i2cSlaveReceive
if(i2cSlaveReceive) i2cSlaveReceive(I2cReceiveDataIndex, I2cReceiveData);
// set state
I2cState = I2C_IDLE;
break;

// Slave Transmitter
case TW_ST_SLA_ACK: // 0xA8: own SLA+R has been received, ACK has been returned
case TW_ST_ARB_LOST_SLA_ACK: // 0xB0: GCA+R has been received, ACK has been returned
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: ST->SLA_ACK\r\n");
rprintfInit(uart1SendByte);
#endif
// we are being addressed as slave for reading (data must be transmitted back to master)
// set state
I2cState = I2C_SLAVE_TX;
// request data from application
if(i2cSlaveTransmit) I2cSendDataLength = i2cSlaveTransmit(I2C_SEND_DATA_BUFFER_SIZE, I2cSendData);
// reset data index
I2cSendDataIndex = 0;
// fall-through to transmit first data byte
case TW_ST_DATA_ACK: // 0xB8: data byte has been transmitted, ACK has been received
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: ST->DATA_ACK\r\n");
rprintfInit(uart1SendByte);
#endif
// transmit data byte
outb(TWDR, I2cSendData[I2cSendDataIndex++]);
if(I2cSendDataIndex < I2cSendDataLength)
// expect ACK to data byte
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
else
// expect NACK to data byte
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT));
break;
case TW_ST_DATA_NACK: // 0xC0: data byte has been transmitted, NACK has been received
case TW_ST_LAST_DATA: // 0xC8:
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: ST->DATA_NACK or LAST_DATA\r\n");
rprintfInit(uart1SendByte);
#endif
// all done
// switch to open slave
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
// set state
I2cState = I2C_IDLE;
break;

// Misc
case TW_NO_INFO: // 0xF8: No relevant state information
// do nothing
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: NO_INFO\r\n");
rprintfInit(uart1SendByte);
#endif
break;
case TW_BUS_ERROR: // 0x00: Bus error due to illegal start or stop condition
#ifdef I2C_DEBUG
rprintfInit(uart1AddToTxBuffer);
rprintf("I2C: BUS_ERROR\r\n");
rprintfInit(uart1SendByte);
#endif
// reset internal hardware and release bus
outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWSTO)|BV(TWEA));
// set state
I2cState = I2C_IDLE;
break;
}
}

eI2cStateType i2cGetState(void)
{
return I2cState;
}