i2c repeate start condition how to wrok

[bhavin]

#define F_CPU 16000000UL

#include <avr/io.h>

#include <util/delay.h>

 

 

 

 

void TWI_init_master(void) // Function to initialize master

{

TWSR = 0x00;   //  TWPS = 00;

TWBR = 0x48;  //   100 khz freq

TWCR = 0x00;

TWCR |= (1<<TWEN);

}

void TWI_start(void)

{

// Clear TWI interrupt flag, Put start condition on SDA, Enable TWI

TWCR= (1<<TWINT)|(1<<TWSTA)|(1<<TWEN);

while(!(TWCR & (1<<TWINT))); // Wait till start condition is transmitted

if ((TWSR & 0xF8) == 0x10);

}

void TWI_REPEATED_START(void)

{

TWCR = (1<<TWINT)|(1<<TWSTA)|(1<<TWEN);

while(!(TWCR & (1<<TWINT)));

}

 

 

void TWI_write_data(unsigned char data)

{

TWDR=data;    // put data in TWDR

TWCR=(1<<TWINT)|(1<<TWEN);    // Clear TWI interrupt flag,Enable TWI

while (!(TWCR & (1<<TWINT))); // Wait till complete TWDR byte transmitted

//while((TWSR & 0xF8) != 0x28); // Check for the acknoledgement

}

void TWI_stop(void)

{

// Clear TWI interrupt flag, Put stop condition on SDA, Enable TWI

TWCR = (1<<TWINT)|(1<<TWSTO)|(1<<TWEN);

_delay_ms(250);

}

 

 

int main(void)

{

while (1)

{

TWI_init_master();

TWI_start();

 

 

 

 

TWI_write_data(0x20);

TWI_write_data(0x59);

TWI_write_data(0x60);

TWI_stop();

_delay_ms(1000);

}

//while(1);

 

[Saatwik]

these both link may help you https://www.engineersgarage.com/tutorials/twi-i2c-interface

https://www.engineersgarage.com/embedded/avr-microcontroller-projects/atmega32-twi-two-wire-interface

[Author]

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