AVR I2C trouble

问题

I am trying to communicate using I2C with AT90CAN128, But it is not going further than following while loop:

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

It remains in the while loop. According to me, it is not able to set TWINT flag.

void TWI_start(void)
{
  TWCR= (1<<TWINT)|(1<<TWSTA)|(1<<TWEN); 
  while(!(TWCR & (1<<TWINT)));`enter code here`
  while((TWSR & 0xF8)!= 0x08); 
}

Any suggestions?

回答1:

Probably a hardware problem.

The TWI Master tries to assert SDA and SCL and checks if both SDA and SCL are at GND. Check the connections and the value of your pull-up resistors. If the controller fails to pull the lines down, the START condition never gets registered and TWINT will never get set.

来源：https://stackoverflow.com/questions/59653754/avr-i2c-trouble