Hi,
I am using I2C protocol (AtMega2560) to write certain registers of the camera module OV7670. Need to implement a repeated start condition for that purpose. I have written the code for that but not sure whether it will work practically or not (i.e. there is no compilation errors).
Actually I have learned the theory of the protocol but implementing it for the first time.
Thanks.
#define F_CPU 16000000UL
#include <avr/io.h>
#include <util/delay.h>
/*I2C Functions Start*/
void twi_init()
{
TWBR = 0xC6; /*SCL would be of 10MHz with Pre-scale of 1*/
TWCR = (1 << TWEN);
TWSR = 0x00; /*Pre-scale is set to 1*/
}
void twiStart (void)
{
TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTA); /*(TWI interrupt cleared) | (TWI enabled) | (TWI start condition)*/
while (!(TWCR & (1 << TWINT))); /*Wait for the start condition to be transmitted*/
TWCR |= (0 << TWSTA); /*Clear the start bit*/
}
void twiStop (void)
{
TWCR |= (1 << TWSTO); /*Set the Stop bit*/
}
void twiWrite (uint8_t deta)
{
TWDR = deta; /*Data to be sent*/
TWCR = (1 << TWINT) | (1 << TWEN);
while (!(TWCR & (1 << TWINT)));
}
/*I2C Functions End*/
/*Sart of the Main Function*/
int main()
{
twi_init();
twiStart(); /*Set the start condition*/
twiWrite(0x42); /*Slave address*/
twiWrite(0x00); /*Address of the first memory location*/
twiWrite(0x02); /*Gain setting*/
_delay_us(500);
twiStart(); /*Repeated Start*/
twiWrite(0x84); /*Blue setting*/
_delay_us(500);
twiStart(); /*Repeated Start*/
twiWrite(0x84); /*Red setting*/
twiStop(); /*Set the Stop Condition*/
while (1);
}
/*End of Main Function*/
