|
|
|
@ -13,20 +13,22 @@
|
|
|
|
|
|
|
|
|
|
void i2c_init(void)
|
|
|
|
|
{
|
|
|
|
|
TWSR = 0; /* no prescaler */
|
|
|
|
|
TWBR = (uint8_t)TWBR_val;
|
|
|
|
|
//TWBR = 10;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
uint8_t i2c_start(uint8_t address)
|
|
|
|
|
{
|
|
|
|
|
// reset TWI control register
|
|
|
|
|
TWCR = 0;
|
|
|
|
|
//TWCR = 0;
|
|
|
|
|
// transmit START condition
|
|
|
|
|
TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
|
|
|
|
|
// wait for end of transmission
|
|
|
|
|
while( !(TWCR & (1<<TWINT)) );
|
|
|
|
|
|
|
|
|
|
// check if the start condition was successfully transmitted
|
|
|
|
|
if((TWSR & 0xF8) != TW_START){ return 1; }
|
|
|
|
|
if(((TW_STATUS & 0xF8) != TW_START) && ((TW_STATUS & 0xF8) != TW_REP_START)){ return 1; }
|
|
|
|
|
|
|
|
|
|
// load slave address into data register
|
|
|
|
|
TWDR = address;
|
|
|
|
@ -51,7 +53,7 @@ uint8_t i2c_write(uint8_t data)
|
|
|
|
|
// wait for end of transmission
|
|
|
|
|
while( !(TWCR & (1<<TWINT)) );
|
|
|
|
|
|
|
|
|
|
if( (TWSR & 0xF8) != TW_MT_DATA_ACK ){ return 1; }
|
|
|
|
|
if( (TW_STATUS & 0xF8) != TW_MT_DATA_ACK ){ return 1; }
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
@ -146,4 +148,6 @@ void i2c_stop(void)
|
|
|
|
|
{
|
|
|
|
|
// transmit STOP condition
|
|
|
|
|
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
|
|
|
|
|
// wait until stop condition is executed and bus released
|
|
|
|
|
while(TWCR & (1<<TWSTO));
|
|
|
|
|
}
|
|
|
|
|